Battery monomer, battery and electric device

Abstract

A single battery, a battery and a power utilization device, the single battery comprises: a housing assembly comprising a housing and a first pole, the first pole comprises a pole body and a first cover plate, the pole body is mounted on the housing, and the first cover plate is arranged on the pole body; the battery core assembly comprises an active substance coating part and a conductive part connected with the active substance coating part, the active substance coating part is accommodated in the shell, and the conductive part is connected with the pole body through a first welding part; the first welding part is at least partially positioned on one side, deviating from the active material coating part, of the pole body, and the first cover plate is used for shielding the first welding part. The reliability of the battery monomer can be improved.

Description

Battery cells, batteries and electrical devices Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] New energy vehicles have experienced rapid growth in recent years. Batteries, as the power source for electric vehicles, play an irreplaceable and important role. Batteries typically consist of multiple cells, which carry a risk of thermal runaway or short circuits during use. This leads to poor reliability and hinders both performance and service life.

[0003] Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can reduce the probability of thermal runaway or short circuit in the battery cell, improve the reliability of the battery cell, and enhance the performance and service life of the battery cell.

[0005] In the first aspect, an embodiment of the present application provides a battery cell, comprising: a shell assembly, comprising a shell and a first pole, the first pole comprising a pole body and a first cover plate, the pole body being mounted on the shell, and the first cover plate being arranged on the pole body; a battery cell assembly, comprising an active material coating portion, and a conductive portion connected to the active material coating portion, the active material coating portion being accommodated in the shell, and the conductive portion being connected to the pole body through a first welding portion; wherein the first welding portion is at least partially located on a side of the pole body facing away from the active material coating portion, and the first cover plate is used to shield the first welding portion.

[0006] In the above technical solution, by positioning the first welding portion at least partially on the side of the electrode body facing away from the active material coating portion, the first welding portion can be reduced from entering the interior of the battery cell, preventing metal residue generated during welding from overlapping the positive and negative electrode sheets to a certain extent, thereby reducing the possibility of internal short circuits in the battery cell. Furthermore, the first welding portion can be positioned away from the active material coating portion. When the electrode body and the conductive portion are welded to form the first welding portion at high temperature, the first welding portion, acting as a high-temperature heat source, can be positioned away from the active material coating portion. This reduces the impact of the high temperature generated by the welding on the active material coating portion, lowering the probability of damage to the active material coating portion and improving the reliability of the battery cell. Furthermore, after the electrode body is welded to the conductive portion within the housing, when the battery cell is welded to the current collector, the first cover plate shields the first welding portion, providing protection, reducing the impact of the high temperature generated by the welding of the electrode body and the current collector on the first welding portion, and improving the reliability of the connection between the electrode body and the conductive portion.

[0007] In some embodiments, the pole body has a first receiving groove, the surface of the first pole facing the active material coating portion is the inner end face of the pole, the notch of the first receiving groove is formed on the inner end face of the pole, and the first receiving groove has a first end wall and a first side wall, the first end wall is located on the side of the first side wall away from the active material coating portion, at least part of the conductive portion is accommodated in the first receiving groove, the first welding portion is provided on the first end wall, and the first cover plate cooperates with the pole body and covers the first welding portion.

[0008] In the above technical solution, on the one hand, the first receiving groove on the first terminal can reduce the weight of the first terminal to a certain extent, thereby improving the weight energy density of the battery cell and the battery. On the other hand, because the notch of the first receiving groove is formed on the inner end surface of the terminal, and the inner end surface of the terminal is the surface of the first terminal close to the active material coating portion, the first receiving groove can be opened toward the active material coating portion, thereby facilitating the insertion of the conductive portion into the first receiving groove and improving assembly efficiency. In addition, this type of first receiving groove is easy to process, improving production efficiency.

[0009] Moreover, the first receiving tank can be easily processed to have a larger volume, which can accommodate more conductive parts. At the same time, since the first receiving tank is open toward the active material coating part, the first receiving tank can also serve as a buffer and temporary storage structure for the electrolyte, so that more electrolyte can be accommodated in the shell. Since the battery cell will lose electrolyte during the charging and discharging process, when there is more electrolyte, the service life of the battery cell can be extended. And because the first receiving tank is open toward the active material coating part, the first receiving tank can also serve as a storage and buffer structure for gas production inside the battery cell assembly, reducing the expansion of the battery cell and improving the reliability and stability of the battery cell.

[0010] Furthermore, because the first receiving groove is located inside the first terminal, foreign matter and impurities are less likely to enter the first receiving groove, thereby reducing the impact of foreign matter and impurities on the cell assembly, improving the stability and reliability of the cell assembly, and thereby improving the stability and reliability of the battery cell and battery. Secondly, by arranging the first weld between the terminal body and the conductive portion on the first end wall, the first weld can be positioned further away from the active material coating portion when within the first receiving groove, further reducing the impact of high temperatures generated when the terminal body and the conductive portion are welded to form the first weld on the active material coating. Furthermore, the first receiving groove not only serves to accommodate at least part of the conductive portion, but also allows the groove wall of the first receiving groove to electrically connect to the conductive portion. This simplifies the structure of the first terminal, facilitates its processing, simplifies the structure of the conductive portion, reduces redundancy in the conductive portion, and reduces the cost of the conductive portion. Furthermore, by welding the first end wall to the conductive portion, the weld area formed by the first weld can be relatively large, reducing the difficulty of welding and improving the reliability and stability of welding, thereby improving the performance of the battery cell.

[0011] In addition, since the first welding portion is located in the first receiving groove, it can not only prevent the first welding portion from protruding outside the first pole and occupying space outside the first pole, but also enable the first welding portion to be protected by the first cover plate, thereby improving the welding reliability and stability of the conductive portion and the first pole.

[0012] In some embodiments, the first end wall has a first recessed groove, and at least a portion of the first welding portion is located in the first recessed groove.

[0013] In the above technical solution, on the one hand, the first sinking groove can be used to pre-position and limit the first welding part, which is not only conducive to finding the correct position for welding and improving production efficiency, but also conducive to improving the stability and reliability of the conductive part, and ensuring the stability and reliability of the battery cell charging and discharging process; on the other hand, by arranging the first sinking groove on the first end wall, the local wall thickness of the first end wall can be locally thinned, which is not only conducive to welding, but also conducive to reducing the weight of the first pole and improving the weight energy density of the battery cell.

[0014] In some embodiments, the first pole has a first groove, the surface of the first pole away from the active material coating portion is the outer end face of the pole, the opening of the first groove is formed on the outer end face of the pole, and the first cover plate covers the opening of the first groove.

[0015] In the above technical solution, on the one hand, since the first pole is provided with the first groove, the weight of the first pole can be further reduced, so as to improve the weight energy density of the battery cell and the battery; on the other hand, the first groove is located on the outside of the first pole, that is, it is open toward the side of the first pole away from the interior of the shell, and the first groove can be used to accommodate or install structural components in the battery that electrically connect the various battery cells, so as to make full use of the space in the first pole and improve the space utilization and volume energy density of the battery; by providing the first groove, the first cover plate is used to cover the notch of the first groove, which facilitates the welding of the first cover plate and improves the assembly efficiency.

[0016] Furthermore, because the first electrode has both a first receiving slot and a first groove, the first groove is located on the side of the first receiving slot away from the active material coating portion and is open away from the first receiving slot. This facilitates laser welding of the conductive portion to the first end wall through the first groove from the outside of the first electrode, i.e., the side of the first electrode away from the active material coating portion, thereby facilitating electrical connection between the conductive portion and the first electrode through external welding. In other words, the above-described structural arrangement facilitates external welding of the first electrode and the conductive portion through the first groove, facilitating processing and manufacturing of the battery cell and saving processing and manufacturing costs.

[0017] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a pole ear portion electrically connected to the current collector, the pole ear portion includes a plurality of pole ear sheets, the plurality of pole ear sheets converge at a position close to the current collector to form a first gathered portion, the plurality of pole ear sheets converge and connect at a position away from the current collector to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, at least a portion of the second gathered portion is accommodated in the first accommodating groove, and the second gathered portion is connected to the first end wall through a first welding portion.

[0018] In the above technical solution, because the tab portion includes a second gathered portion formed by the convergence and connection of multiple tab sheets, at least a portion of the second gathered portion is accommodated within the first receiving groove, facilitating connection between the conductive portion and the first terminal, fully utilizing the space within the first terminal, and improving the volumetric energy density of the battery cell. When the second gathered portion is electrically connected to the first end wall via the first welding portion, such as when the second gathered portion is welded (e.g., laser welded) to the first end wall, the battery cell assembly can be simplified, reducing component count, streamlining the assembly process, and improving assembly efficiency.

[0019] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a pole ear portion and a transfer plate, the pole ear portion includes a plurality of pole ear plates, the plurality of pole ear plates converge at a position close to the current collector to form a first gathered portion, the plurality of pole ear plates converge and connect at a position away from the current collector to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, the transfer plate is connected to the second gathered portion, at least a portion of the transfer plate is accommodated in the first accommodating groove, and the transfer plate is connected to the first end wall through a first welding portion.

[0020] In the above technical solution, on the one hand, by at least partially housing the adapter plate within the first receiving groove, the space within the first electrode can be more fully utilized, further reducing the space occupied by the conductive portion within the housing, thereby improving the volumetric energy density of the battery cell. On the other hand, by using the adapter plate and the first welding portion to achieve indirect electrical connection between the second folded portion and the first electrode, the adapter plate can be welded to the first electrode at a location that avoids the second folded portion, thereby ensuring a secure weld between the adapter plate and the first electrode, minimizing the risk of weld cracking, and further improving the reliability and stability of the battery cell. Furthermore, the use of the adapter plate to electrically connect the first electrode and the tab can also simplify the tab structure.

[0021] In some embodiments, at least a portion of the first folded portion is received in the first receiving groove.

[0022] In the above technical solution, at least part of the first folded portion of the pole ear is accommodated in the first accommodating groove, which can make more effective use of the space in the first pole column, further reduce the space occupied by the pole ear in the shell, so as to accommodate a larger active material coating portion, improve the volume energy density of the battery cell, and better reduce the redundancy of the pole ear in the shell, further reducing the probability of short circuit between the pole ear and the active material coating portion.

[0023] In some embodiments, the housing has a mounting hole, and the first pole is mounted in the mounting hole; along the axial direction of the first pole, the depth H1 of the first accommodating groove is greater than or equal to the minimum distance H2 from the inner end surface of the pole to the mounting hole.

[0024] In the above technical solution, since the depth H1 of the first accommodating groove is greater than or equal to the minimum distance H2 from the inner end face of the pole to the mounting hole in the axial direction of the first pole, the volume of the first pole can be fully utilized, so that the first accommodating groove has a larger depth, which is conducive to accommodating more conductive parts, and thus can greatly reduce the space occupied by the conductive parts in the shell, further improve the energy density of the battery cell, and further reduce the redundancy of the conductive parts in the shell; at the same time, since the first accommodating groove has a larger depth, it can also accommodate the gas production of the battery cell assembly, ensure the reliability and stability of the battery cell, and can also accommodate more electrolyte to ensure the service life of the battery cell.

[0025] In some embodiments, the pole body has a second receiving groove, the surface of the pole body away from the active material coating part is the outer end face of the pole, the notch of the second receiving groove is formed on the outer end face of the pole, the second receiving groove has a second end wall close to the active material coating part, the first welding part is arranged on the second end wall, the first cover plate cooperates with the pole body and covers the notch of the second receiving groove.

[0026] In the above technical solution, on the one hand, the second receiving groove provided in the first terminal can reduce the weight of the first terminal to a certain extent, thereby improving the weight energy density of the battery cell and the battery. On the other hand, because the notch of the second receiving groove is formed on the outer end surface of the terminal, and the outer end surface of the terminal is the surface of the first terminal away from the active material coating portion, the second receiving groove can be open in a direction away from the active material coating portion. In this way, when at least a portion of the conductive portion is accommodated in the second receiving groove, the conductive portion can be easily stored and organized through the notch of the second receiving groove, and the conductive portion can be easily electrically connected to the first terminal through the notch of the second receiving groove, thereby reducing the difficulty of battery cell production and improving battery cell production efficiency. In particular, the first welding portion is provided on the second end wall. That is, the second receiving groove not only serves to accommodate at least a portion of the conductive portion, but the groove wall of the second receiving groove also serves to weld to the conductive portion. This can simplify the structure of the first terminal and facilitate its processing. Moreover, the opening direction of the slot of the second receiving slot makes it easy to weld the conductive part to the slot wall of the second receiving slot through the slot of the second receiving slot, which can reduce the difficulty of welding. The slot wall of the second receiving slot is used to achieve welding connection with the conductive part, which can make the welding area formed by the first welding part between the conductive part and the first pole relatively large, thereby improving the reliability and stability of the electrical connection and thereby improving the performance of the battery cell.

[0027] Furthermore, since the conductive part is connected to the pole body through the first welding part, there is welding slag at the first welding part. The first welding part is arranged on the second end wall, so that the welding slag can be kept away from the active material coating part, reducing the amount of welding slag entering the interior of the shell. On the other hand, the first cover plate blocks the first welding part to protect the first welding part, so that the welding slag or part of the welding slag falling on the first welding part can be blocked by the first cover plate, further reducing the amount of welding slag entering the interior of the shell. By reducing the entry of welding slag into the shell twice, the risk of short circuit inside the battery cell due to the presence of welding slag can be greatly reduced, thereby improving the reliability of the battery cell.

[0028] In addition, when the battery cell transmits electricity to the outside, the pole body needs to be electrically connected to the busbar component. At this time, the pole body and the busbar component are welded. In this case, since the first cover plate can cover the first welding part, the busbar component will not contact the first welding part, or it can be understood that the busbar component and the first welding part can be isolated from each other, which can also reduce the impact of the first welding part on other welding positions on the pole body.

[0029] In some embodiments, the conductive portion is located on a side of the second end wall facing the active material coating portion.

[0030] In the above technical solution, the first welding portion is arranged on the side of the second end wall facing the active material coating portion. At this time, the distance between the first welding portion and the surface of the pole body located outside the shell is relatively far, which can reduce the impact of the high temperature generated when the pole body and the busbar component are welded on the first welding portion.

[0031] In some embodiments, the second receiving groove is connected to the interior of the shell through the first perforation, the conductive part is passed through the first perforation and is at least partially received in the second receiving groove, and the conductive part is at least partially arranged on the side of the second end wall away from the active material coating part.

[0032] In the above technical solution, since the second receiving tank can be connected to the interior of the shell through the first perforation, the second receiving tank can also serve as a buffer and temporary storage structure for the electrolyte, so that more electrolyte can be accommodated in the shell. Since the battery cell will lose electrolyte during the charging and discharging process, when there is more electrolyte, the service life of the battery cell can be extended; and because the second receiving tank can be connected to the interior of the shell through the first perforation, the second receiving tank can also serve as a storage and buffer structure for gas generated inside the battery cell assembly, reducing the expansion of the battery cell and improving the reliability and stability of the battery cell.

[0033] In some embodiments, the second receiving groove further has a second side wall, which is located on the side of the second end wall away from the active material coating portion, and the second side wall and the second end wall are arranged to form a second receiving groove, the first through-hole is opened on the second end wall, and the second end wall has a second sinking groove, and at least part of the first welding portion is located in the second sinking groove.

[0034] In the above technical solution, on the one hand, the first through-hole provided in the second end wall facilitates the conductive portion to extend through the first through-hole into the second receiving groove, thereby simplifying the conductive portion structure, reducing redundancy, and lowering the cost of the conductive portion. On the other hand, the portion of the first welding portion located within the second recessed groove is configured to match the shape of the second recessed groove and fit snugly to achieve electrical connection. This allows the second recessed groove to pre-position and limit the electrical connection position of the conductive portion, facilitating accurate electrical connection, improving production efficiency, and enhancing the stability and reliability of the electrical connection position, thereby ensuring reliable and stable charging and discharging operations of the battery cells.

[0035] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a pole ear portion electrically connected to the current collector, the pole ear portion includes a plurality of pole ear sheets, the plurality of pole ear sheets converge at a position close to the current collector to form a first gathered portion, the plurality of pole ear sheets converge and connect at a position away from the current collector to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, at least a portion of the second gathered portion is accommodated in the second accommodating groove, and the second gathered portion is connected to the second end wall through a first welding portion.

[0036] In the above technical solution, because the tab portion includes a second, converged portion formed by the convergence and connection of multiple tab sheets, at least a portion of the second, converged portion can be easily accommodated within the second receiving groove, facilitating welding of the conductive portion to the first terminal. Furthermore, accommodating at least a portion of the second, converged portion within the second receiving groove utilizes the space within the first terminal, reducing the space occupied by the conductive portion within the housing and improving the volumetric energy density of the battery cell.

[0037] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a pole ear portion and a transfer plate, the pole ear portion is electrically connected to the current collector, the pole ear portion includes a plurality of pole ear sheets, the plurality of pole ear sheets converge at a position close to the current collector to form a first gathered portion, the plurality of pole ear sheets converge and connect at a position away from the current collector to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, the transfer plate is connected to the second gathered portion, at least a portion of the transfer plate is accommodated in the second accommodating groove, and the transfer plate is connected to the second end wall through a first welding portion.

[0038] In some embodiments, at least a portion of the first folded portion is received in the second receiving groove.

[0039] In the above technical solution, by accommodating at least a portion of the first accordion portion and the adapter plate within the second receiving groove, the space within the first terminal column can be more fully utilized, further reducing the space occupied by the conductive portion within the housing, thereby further improving the volumetric energy density of the battery cell. Furthermore, by providing the adapter plate with a sheet structure, the adapter plate can be easily inserted through the first perforation into the second receiving groove.

[0040] In some embodiments, the pole body is provided with a first accommodating portion, the first accommodating portion has a third accommodating groove, the surface of the first pole facing the active material coating portion is the inner end face of the pole, the third accommodating groove is located on the side of the second accommodating groove close to the active material coating portion, and the notch of the third accommodating groove is formed on the inner end face of the pole, the third accommodating groove is connected to the second accommodating groove through a first through-hole, and at least part of the first retracted portion is accommodated in the third accommodating groove.

[0041] In the above technical solution, a portion of the conductive part is located in the third accommodating groove, and the conductive part is also passed through the first through-hole, and the rest of the conductive part is located in the second accommodating groove, so that the space in the first pole can be more fully utilized and the space occupied by the conductive part in the shell can be reduced.

[0042] In some embodiments, the housing assembly further includes a second cover plate, which is disposed to cover the first through-hole and the conductive portion located in the second receiving groove.

[0043] In the above technical solution, at least part of the conductive part is located in the second receiving groove, the second cover plate is covered on the conductive part of this part, and the second cover plate is also covered with the first perforation, so that when the electrolyte enters the second receiving groove from the first perforation, the second cover plate can improve the problem of the electrolyte overflowing from the first pole, thereby improving the reliability of the battery cell.

[0044] In some embodiments, the housing has a mounting hole, the first pole is mounted in the mounting hole, and along the axial direction of the first pole, the depth H3 of the second receiving groove is greater than or equal to the minimum distance H4 from the outer end surface of the pole to the mounting hole.

[0045] In the above technical solution, the depth H3 of the second receiving groove refers to the maximum depth of the second receiving groove along the axial direction of the first pole. Since the depth H3 of the second receiving groove is greater than or equal to the minimum distance H4 between the outer end face of the pole and the mounting hole in the axial direction of the first pole, the volume of the first pole can be fully utilized, resulting in a larger depth of the second receiving groove, which is conducive to accommodating more conductive parts, thereby significantly reducing the space occupied by the conductive parts within the housing, further improving the energy density of the battery cell, and further reducing the redundancy of the conductive parts within the housing. At the same time, the greater depth of the second receiving groove can also accommodate gas generation from the battery cell assembly, ensuring the reliability and stability of the battery cell, and can also accommodate more electrolyte to ensure the service life of the battery cell.

[0046] In some embodiments, the pole body is provided with a first accommodating portion, the first accommodating portion has a fourth accommodating groove, the surface of the pole body away from the active material coating portion is the outer end face of the pole, the notch of the fourth accommodating groove is formed on the outer end face of the pole, the fourth accommodating groove is connected to the interior of the shell through the second through-hole, the conductive portion is passed through the second through-hole, the first welding portion is provided on the hole wall of the second through-hole formed by the first accommodating portion, the first cover plate cooperates with the pole body and covers the second through-hole.

[0047] In the above technical solution, the provision of the fourth receiving groove facilitates welding of the conductive portion to the wall of the second through-hole. Furthermore, in some cases, the electrical connection between the conductive portion and the first electrode can be utilized to seal the second through-hole. For example, the conductive portion can be welded to the wall of the second through-hole at the location where the second through-hole connects to the fourth receiving groove, thereby facilitating the welding process. Furthermore, by controlling the weld mark, the weld mark and the conductive portion can be used to seal the second through-hole, thereby alleviating the problem of electrolyte leakage from the housing through the second through-hole.

[0048] In some embodiments, the pole body includes a first pole portion and a second pole portion made of different materials and electrically connected, the second pole portion is located on the side of the first pole portion away from the active material coating portion, the first accommodating portion is arranged on the first pole portion or on the first pole portion and the second pole portion, and the first welding portion is arranged on the first pole portion.

[0049] In the above technical solution, by setting the first pole as a composite form composed of different materials, the first pole part located on the inner side is accommodated and electrically connected to the conductive part, and the second pole part located on the outer side is electrically connected to the busbar component, etc., which is conducive to the assembly and electrical connection of the first pole and related components, reduces the mutual interference between the welding position of the first pole and the conductive part and the welding position of the first pole and the battery busbar component, and improves the reliability and stability of the battery cell.

[0050] In some embodiments, the first cover plate is provided with a second accommodating portion, the second accommodating portion has a fifth accommodating groove, the groove opening of the fifth accommodating groove is formed on an end face of the first cover plate facing the active material coating portion, and the fifth accommodating groove has a third end wall and a third side wall, the third end wall is located on the side of the third side wall away from the active material coating portion, and at least part of the first welding portion is accommodated in the fifth accommodating groove.

[0051] In the above technical solution, on the one hand, the first cover plate is provided with a fifth receiving groove, which can reduce the weight of the first electrode to a certain extent, so as to improve the weight energy density of the battery cell and the battery; on the other hand, since the notch of the fifth receiving groove is formed on the end face of the first cover plate facing the active material coating portion, and the third end wall is located on the side of the third side wall away from the active material coating portion, the fifth receiving groove can be open in the direction away from the active material coating portion. In this way, when at least part of the conductive portion is accommodated in the fifth receiving groove, the first welding portion can be easily accommodated and sorted through the notch of the fifth receiving groove, thereby reducing the production difficulty of the battery cell and improving the production efficiency of the battery cell.

[0052] In some embodiments, the first cover plate is electrically connected to the pole body; or the first cover plate is insulated from the pole body.

[0053] In the above technical solution, the first cover plate can be electrically connected to the pole body. In this case, the first cover plate can also participate in the electrical connection with the busbar, thereby increasing the area of ​​the weldable area and facilitating the welding of the first pole and the busbar. The first cover plate can also be electrically insulated from the pole body. In this case, the first cover plate primarily serves to protect the first weld.

[0054] In some embodiments, the first cover plate includes a first conductive member and a second conductive member made of different materials. The first conductive member cooperates with and is electrically connected to the pole body, and the second conductive member cooperates with and is electrically connected to the first conductive member.

[0055] In the above technical solution, the first cover is configured as a composite form, and the first conductive member is configured to be made of the same material as the first pole, thereby facilitating electrical connection between the first conductive member and the first pole. For example, the first conductive member and the first pole can be easily and reliably connected by welding. Furthermore, because the second conductive member is made of a different material than the first conductive member, it is convenient to use the second conductive member to electrically connect to a busbar component made of a different material than the first pole. For example, the second conductive member can be easily and reliably connected to a busbar component made of the same material as the second conductive member by welding.

[0056] In some embodiments, the first conductive member has a second groove, the second conductive member is embedded in the second groove, and the notch of the second groove is formed on the surface of the first conductive member away from the active material coating portion, so that the second conductive member is exposed from the notch of the second groove.

[0057] In the above technical solution, on the one hand, by embedding the second conductive member within the first conductive member, the difficulty of assembling the first and second conductive members can be reduced, improving the stability and convenience of the cooperation between the first and second conductive members. It can also reduce the thickness of the first cover plate, reducing the space occupied by the first cover plate, thereby improving the space utilization of the battery cell. On the other hand, because the second conductive member can be exposed from the surface of the first conductive member away from the second receiving groove through the notch of the second groove, it is convenient to achieve electrical connection between the second conductive member and the busbar outside the first terminal.

[0058] In addition, since the notch of the second groove is formed on the surface of the first conductive member away from the second receiving groove, it means that the second groove is open in the direction away from the active material coating portion, so that the portion of the groove wall of the first conductive member used to define the second groove is located between the second receiving groove and the second conductive member to separate the second receiving groove and the second conductive member, thereby preventing the electrolyte entering the second groove from contacting the second conductive member and reducing leakage of the electrolyte.

[0059] In some embodiments, the first cover plate has a stress relief groove, and the stress relief groove is located in the outer peripheral area of ​​the first cover plate.

[0060] In the above technical solution, by setting a stress relief groove on the first cover plate, the stress generated during the first cover plate's own processing or during the electrical connection between the first cover plate and the first pole can be released, thereby improving related problems such as deformation or damage of the first cover plate due to stress.

[0061] In some embodiments, the battery cell further includes: a bracket located inside the shell and on the side of the active material coating portion close to the first pole, the bracket having an avoidance hole for avoiding the conductive portion, and the conductive portion is suitable for extending to the side of the bracket away from the active material coating portion through the avoidance hole.

[0062] In the above technical solution, a bracket is provided on the side of the active material coating part close to the first pole, so that the bracket can be used to separate the active material coating part from the shell, thereby improving the reliability of the battery cell, and an avoidance hole is provided on the bracket, which can guide and constrain the conductive part to cooperate with the first pole by passing through the avoidance hole, thereby eliminating the need for the conductive part to bypass the edge of the bracket to approach the first pole, thereby not only simplifying the arrangement of the conductive part, saving the material of the conductive part, and reducing the cost, but also supporting and guiding the conductive part to cooperate with the first pole by the bracket, which can reduce the risk of short-circuit connection between the conductive part and the active material coating part, thereby further improving the reliability of the battery cell.

[0063] In some embodiments, the pole body is provided with a first accommodating portion, the bracket is provided with a guide portion, the guide portion surrounds at least a portion of the avoidance hole, and the guide portion at least partially extends to the first accommodating portion.

[0064] In the above technical solution, the guide portion protrudes from the bracket and extends into the first accommodating portion, and at least a portion of the avoidance hole is formed in the guide portion, so that when the conductive portion is passed through the avoidance hole, at least a portion of the conductive portion can be easily received in the first accommodating portion, thereby improving the assembly efficiency of the conductive portion; at the same time, through the provision of the guide portion, the cooperation between the bracket and the first pole, and between the bracket and the conductive portion are tighter and more reliable, making the structure of the battery cell more compact, which is more conducive to improving the energy density of the battery cell.

[0065] In some embodiments, the avoidance hole includes a first hole segment and a second hole segment, the second hole segment is located on a side of the first hole segment close to the active material coating portion, and the cross-sectional area of ​​the second hole segment gradually increases in a direction away from the first hole segment, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a pole ear portion electrically connected to the current collector, the pole ear portion includes a plurality of pole ear sheets, the plurality of pole ear sheets converge at a position close to the current collector to form a first gathering portion, the plurality of pole ear sheets converge and are connected at a position away from the current collector to form a second gathering portion, the first gathering portion connects the second gathering portion and the active material coating portion, at least a portion of the first gathering portion is accommodated in the second hole segment, and the second gathering portion passes through the first hole segment.

[0066] In the above technical solution, by setting the avoidance hole to include a second hole segment that gradually expands in the direction of the active material coating portion, it is convenient for the second hole segment to accommodate more first folded portions, thereby improving the compactness of the cooperation between the bracket and the battery cell assembly, so that the overall volume of the battery cell is smaller, and the battery can accommodate a larger number of battery cells, thereby improving the volume energy density of the battery.

[0067] In some embodiments, the bracket is an integrated structure; or, the bracket is a split structure and includes a detachable first bracket and a second bracket, and an avoidance hole is defined between the first bracket and the second bracket.

[0068] In the above technical solution, the avoidance hole is formed in the form of a through hole that passes through the bracket. As a result, the bracket with an integrated structure is easy to process, and the reliability of the bracket is good, and it is convenient to assemble the bracket with the shell assembly, thereby improving assembly efficiency and matching stability. When the bracket is a split structure, the bracket includes a detachable first bracket and a second bracket, and the first bracket and the second bracket are both long plate-like structures, and the two can be detachably connected, for example, the two can be plugged in or snap-fitted to facilitate assembly. The avoidance hole is defined by the cooperation of the first bracket and the second bracket. When the bracket and the battery cell assembly are assembled, there is no need to pass the conductive part from one end of the avoidance hole to the other end. Instead, the first bracket and the second bracket can be spliced ​​at the position of the conductive part to clamp the conductive part, so that the avoidance hole surrounds the conductive part, thereby facilitating the assembly of the bracket and the battery cell assembly and improving assembly efficiency.

[0069] In some embodiments, the shell has a first wall, a mounting hole is formed in the first wall, the pole body is arranged in the mounting hole, and the surface where the cross section of the mounting hole is located is the projection surface. Along the direction perpendicular to the projection surface, the ratio of the projection area of ​​the first welding portion on the projection surface to the projection area of ​​the first wall on the projection surface is in the range of 0.1% to 1%.

[0070] In the above technical solution, by setting the ratio of the projected area of ​​the first welding portion on the projection surface to the projected area of ​​the first wall on the projection surface within the range of 0.1% to 1%, the effective flow area between the conductive portion and the pole body is increased, the flow area of ​​the first pole is increased, and the flow capacity of the first pole is increased, which is beneficial to improving the charging speed of the battery cell. At the same time, it is also beneficial to improve the thermal diffusion capacity of the first pole to a certain extent, reduce the overcurrent temperature of the first pole, and help reduce the risk of loss of control of the battery cell.

[0071] In some embodiments, the shell has a mounting hole, and the pole body includes an integrally formed pole body portion, a first limit platform portion, and a second limit platform portion. The pole body portion is passed through the mounting hole, and the first limit platform portion and the second limit platform portion are arranged at both ends of the pole body portion along the axial direction of the mounting hole. The first limit platform portion is limited and matched with the outer side of the shell, and the second limit platform portion is limited and matched with the inner side of the shell, so that the pole body is riveted to the shell.

[0072] In the above technical solution, the first limit platform portion and the second limit platform portion respectively extend along the radial direction of the mounting hole to the radial outside of the peripheral wall of the mounting hole. The first limit platform portion can limit the movement of the first pole relative to the shell in the direction toward the inside of the shell, and the second limit platform portion can limit the movement of the first pole relative to the shell in the direction toward the outside of the shell, so that the first pole can be easily and reliably installed at the mounting hole through the first limit platform portion and the second limit platform portion, thereby realizing a fixed connection between the first pole and the shell, facilitating the assembly of the first pole and the shell, and there is no need to adopt other connection methods between the first pole and the shell, that is, it is easy to realize a reliable connection between the first pole and the shell, which is conducive to simplifying the structure of the shell assembly and simplifying the assembly process of the shell assembly.

[0073] Moreover, since the pole body, the first limit platform and the second limit platform are formed as one piece, it is possible to save parts and reduce costs. At the same time, it is easy to ensure the strength of the first pole, so that after the first pole is matched with the shell, it is not easy for the first pole to separate from the shell due to vibration or external pulling during the charging and discharging process of the battery cell, nor is it easy to crack or be damaged due to vibration or external pulling. It can improve the stability and reliability of the shell assembly, thereby improving the stability and reliability of the battery cell.

[0074] In some embodiments, the battery cell further includes an external insulating member wrapped around the outer shell. In the above technical solution, the external insulating member serves as an insulator, separating the outer shell from external components. For example, the external insulating member is a blue film.

[0075] In some embodiments, the shell has a first wall, the first wall is formed with a mounting hole, the pole body is arranged in the mounting hole, the battery cell also includes a patch covering the outside of the first wall, the external insulating part includes an external insulating film, the external insulating film is an integrated diaphragm, the external insulating film has a connecting portion, the connecting portion extends to the outside of the first wall and is connected to the patch.

[0076] In the above technical solution, the connecting portion can overlap with the patch along the axial direction of the mounting hole, facilitating the connection between the connecting portion and the patch. In this case, the outer insulating film and the patch can at least separate the first pole on the first wall from the housing, improving the insulation reliability between the first pole and the housing, thereby improving the reliability of the battery cell. For example, the connecting portion can extend in an annular shape around the outer periphery of the first wall, so that the outer insulating member wraps around all walls of the housing except the first wall. The connecting portion is located between the patch and the first wall, so that the patch can provide a certain degree of protection for the connection between the connecting portion and the patch.

[0077] In some embodiments, the minimum distance between the edge of the outer insulating film and the first pole is greater than or equal to 3 mm. In this technical solution, the creepage distance between the first pole and the housing can be greater than or equal to 3 mm, which is conducive to improving the insulation withstand voltage performance between the first pole and the housing.

[0078] In a second aspect, an embodiment of the present application provides a battery, comprising the battery cell described above.

[0079] In the above technical solution, by locating the first welding portion of the battery cell at least partially on the side of the electrode body facing away from the active material coating portion, the first welding portion can be distanced from the active material coating portion. When the electrode body and the conductive portion are welded at high temperature to form the first welding portion, the first welding portion, acting as a high-temperature heat source, can be distanced from the active material coating portion. Therefore, the effect of the high temperature generated by the welding on the active material coating portion can be reduced, reducing the probability of damage to the active material coating portion and improving the reliability of the battery cell. Furthermore, after the electrode body is welded to the conductive portion inside the housing, when the battery cell is welded to the busbar, the first welding portion can be shielded by the first cover plate to provide protection, reducing the effect of the high temperature generated during the welding of the electrode body and the busbar on the first welding portion, and improving the reliability of the first welding portion between the electrode body and the conductive portion. It can be seen that by providing a battery including the above-described battery cell, the reliability of the battery can be improved.

[0080] In some embodiments, the battery further includes: a plurality of battery cells; a busbar component, the busbar component being electrically connected to the first poles of at least two battery cells, the first poles of the same polarity of each battery cell being electrically connected to the busbar component via a second welding portion, the second welding portion being formed on the first cover plate; wherein the shell includes a first wall, the first wall being formed with a mounting hole, the pole body being arranged in the mounting hole, and on a cross section of the mounting hole, the orthographic projection area of ​​the second welding portion being greater than or equal to 0.2% of the orthographic projection area of ​​the first wall.

[0081] In the above technical solution, by setting the orthographic projection area of ​​the second welding portion between the busbar component and the corresponding first pole on the cross-section of the mounting hole to be greater than or equal to 0.2% of the orthographic projection area of ​​the first wall, the effective flow area between the busbar component and the corresponding first pole is made greater than or equal to 0.2% of the orthographic projection area of ​​the first wall, so as to increase the effective flow area of ​​the busbar component and the first pole, increase the flow area of ​​the first pole, and improve the flow capacity of the first pole, which is beneficial to improving the charging speed of the battery cell. At the same time, it is also beneficial to improve the thermal diffusion capacity of the first pole to a certain extent, reduce the overcurrent temperature of the first pole, and help reduce the risk of loss of control of the battery cell.

[0082] In some embodiments, along a direction perpendicular to the cross section of the mounting hole, the overlapping portion of the busbar component and the pole body of the same polarity is the weldable area of ​​the busbar component, and the positive projection area of ​​the second welding portion on the cross section of the mounting hole is greater than or equal to 0.2 of the weldable area of ​​the busbar component.

[0083] In the above technical solution, the weldable area of ​​the busbar overlaps the pole body in a direction perpendicular to the projection plane, or in other words, the projection of the weldable area of ​​the busbar on the cross-section of the mounting hole and the projection of the pole body on the cross-section of the mounting hole in a direction perpendicular to the projection plane at least partially overlap. The weldable area of ​​the busbar can be understood as the area provided by the busbar that can be welded to the pole body. The area of ​​the weldable area must be greater than or equal to the orthographic projection area of ​​the second weld portion on the projection plane. The projected area of ​​the second weld portion on the projection plane has an appropriate proportion to facilitate the welding operation between the busbar and the pole body while appropriately improving the current carrying capacity and heat dissipation capacity of the pole body.

[0084] In some embodiments, along a direction perpendicular to the cross section of the mounting hole, the overlapping portion of the busbar component and the first pole of the same polarity is the weldable area of ​​the busbar component, and the area of ​​the weldable area of ​​the busbar component is greater than or equal to 20% of the positive projection area of ​​the busbar component on the cross section of the mounting hole.

[0085] In the above technical solution, the weldable area of ​​the conduit component overlaps with the first pole of the same polarity along the direction perpendicular to the cross section of the mounting hole, or in other words, along the direction perpendicular to the cross section of the mounting hole, the orthographic projection of the weldable area of ​​the conduit component on the cross section of the mounting hole overlaps at least partially with the orthographic projection of the first pole of the same polarity on the cross section of the mounting hole; the weldable area of ​​the conduit component can be understood as the area provided by the conduit component that can be welded to the first pole, and the area of ​​the weldable area of ​​the conduit component must be greater than or equal to the orthographic projection area of ​​the second welding portion on the cross section of the mounting hole. The area of ​​the weldable area of ​​the conduit component is greater than or equal to 20% of the orthographic projection area of ​​the conduit component on the cross section of the mounting hole. This allows the conduit component to provide sufficient weldable area to lay the foundation for improving the flow capacity and heat diffusion capacity of the first pole.

[0086] In some embodiments, the area of ​​the weldable region of the busbar component is less than or equal to 50% of the orthographic projection area of ​​the busbar component on the cross section of the mounting hole.

[0087] In the above technical solution, by setting the area of ​​the weldable area of ​​the busbar component to be greater than or equal to 50% of the positive projection area of ​​the busbar component on the cross section of the mounting hole, it is beneficial to further take into account the current carrying capacity of the first pole and the convenience of welding operation.

[0088] In a third aspect, an embodiment of the present application provides an electrical device comprising the battery described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0090] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0091] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0092] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0093] FIG4 is an orthographic view of a battery cell provided in some embodiments of the present application;

[0094] FIG5 is a cross-sectional view along line AA in FIG4 ;

[0095] FIG6 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0096] FIG7 is an assembly diagram of a second pole, a cell assembly, and a housing provided in some embodiments of the present application;

[0097] FIG8 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0098] FIG9 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0099] FIG10 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0100] FIG11 is a partial cross-sectional schematic diagram of a battery cell assembly provided in some embodiments of the present application;

[0101] FIG12 is a diagram illustrating various tab folding schemes for battery cell assemblies provided in some embodiments of the present application;

[0102] FIG13 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0103] FIG14 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0104] FIG15 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0105] FIG16 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0106] FIG17 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0107] FIG18 is a partial enlarged view of point B in FIG3 ;

[0108] FIG19 is an orthographic projection view of various first poles provided in some embodiments of the present application;

[0109] FIG20 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0110] FIG21 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0111] FIG22 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0112] FIG23 is an exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0113] FIG24 is a partial cross-sectional schematic diagram of a housing assembly provided in some embodiments of the present application;

[0114] FIG25 is an exploded view of the structure of the housing assembly shown in FIG24;

[0115] FIG26 is an exploded view of the structure of the first cover plate shown in FIG25 ;

[0116] FIG27 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0117] FIG28 is an exploded view of the structure of the battery cell shown in FIG27;

[0118] FIG29 is a partial cross-sectional schematic diagram of a battery cell provided by some embodiments of the present application;

[0119] FIG30 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0120] FIG31 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0121] FIG32 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0122] FIG33 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0123] FIG34 is a schematic diagram of the cooperation between a battery cell assembly and a bracket provided in some embodiments of the present application;

[0124] FIG35 is a cross-sectional view taken along line CC in FIG34;

[0125] FIG36 is a schematic structural diagram of an integrated bracket provided in some embodiments of the present application;

[0126] FIG37 is a schematic structural diagram of a split bracket provided in some embodiments of the present application;

[0127] FIG38 is a partial cross-sectional schematic diagram of a battery cell assembly and a bracket provided in some embodiments of the present application;

[0128] FIG39 is an exploded view of the structure of a battery cell assembly, a bracket, and a housing assembly provided in some embodiments of the present application;

[0129] FIG40 is an exploded view of the structure of the first pole, the housing, and the sealing gasket provided in some embodiments of the present application;

[0130] FIG41 is an assembly diagram of the first pole, housing, and sealing gasket shown in FIG40 ;

[0131] FIG42 is a schematic structural diagram of a first pole provided in some embodiments of the present application;

[0132] FIG43 is an assembly diagram of a first pole, a housing, and a sealing gasket provided in some embodiments of the present application;

[0133] FIG44 is an exploded view of the structure of the first pole shown in FIG43;

[0134] FIG45 is an orthographic view of a battery cell provided by some embodiments of the present application;

[0135] FIG46 is an orthographic view of a battery cell provided by some embodiments of the present application;

[0136] FIG47 is a cross-sectional view taken along line DD in FIG46;

[0137] FIG48 is a schematic cross-sectional view of a housing assembly provided in some embodiments of the present application;

[0138] FIG49 is a schematic cross-sectional view of a housing assembly provided in some embodiments of the present application;

[0139] FIG50 is an orthographic view of a battery cell provided by some embodiments of the present application;

[0140] FIG51 is a cross-sectional view taken along line EE in FIG50;

[0141] FIG52 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0142] FIG53 is a schematic diagram of the structure of a housing cover provided in some embodiments of the present application;

[0143] FIG54 is a partial schematic diagram 1 of a battery cell provided in some embodiments of the present application;

[0144] FIG55 is a second partial schematic diagram of a battery cell provided in some embodiments of the present application;

[0145] FIG56 is a schematic diagram of a battery cell provided in one embodiment of the present application;

[0146] FIG57 is a schematic diagram of the electrical connection between a battery cell and a busbar component provided in one embodiment of the present application;

[0147] FIG58 is a schematic diagram of the electrical connection between the busbar component and the pole according to an embodiment of the present application;

[0148] FIG59 is a schematic diagram showing the connection between the first polarity pole and the conductive portion of the battery cell shown in FIG56 ;

[0149] FIG60 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0150] FIG61 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0151] FIG62 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0152] FIG63 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0153] FIG64 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0154] FIG65 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0155] FIG66 is a schematic diagram of a battery cell assembly provided in one embodiment of the present application;

[0156] FIG67 is a schematic diagram of the arrangement of first polarity poles and second polarity poles provided in one embodiment of the present application;

[0157] FIG68 is a schematic diagram of the arrangement of first polarity poles and second polarity poles provided in one embodiment of the present application;

[0158] FIG69 is a schematic diagram of the arrangement of first polarity poles and second polarity poles provided in one embodiment of the present application;

[0159] FIG70 is a schematic diagram of the arrangement of first polarity poles and second polarity poles provided in one embodiment of the present application;

[0160] FIG71 is a schematic diagram of the arrangement of the first polarity pole and the second polarity pole provided in an embodiment of the present application

[0161] FIG72 is a schematic diagram of the arrangement of first polarity poles and second polarity poles provided in one embodiment of the present application;

[0162] FIG73 is a schematic diagram of the installation of a first polarity pole provided in one embodiment of the present application;

[0163] FIG74 is a schematic diagram of a battery cell provided in one embodiment of the present application;

[0164] FIG75 is a schematic diagram showing the connection between the outer insulating member and the patch shown in FIG74 .

[0165] Attached Labels: Icon: Electric device 1000; Battery 100; Controller 200; Motor 300; First direction Z; Second direction X; Third direction Y; Axial direction R of first pole; Battery cell 10; Housing 20; First housing 201; Second housing 202; Current collector 30; Housing assembly 1; Housing 11; First wall 110; Second wall 120; Housing body 111; Housing cover 112; Mounting hole 113; Separate hole 1131; Second mounting hole 114; First pole 12; First polarity pole 12A; Second polarity pole 12B; First accommodating portion 121; First accommodating groove 12110; First end wall 12111; First recessed groove 12112; First side wall 12113; Second accommodating groove 12120; Second end wall 12121; Second recessed groove 12122; Second side wall 12123; First slot section 12124; second slot section 12125; guide slope 12126; step surface 12127; first through-hole 12130; third accommodating slot 12140; fourth accommodating slot 12150; second through-hole 12160; third through-hole 12170; pole inner end surface 122; pole outer end surface 123; first pole portion 124; second pole portion 125; first groove 126; spacer 127; stopper 1281; perforation portion 1282; flange portion 1283; pole body 1201; pole main body 12a; first limiting platform 12b; second limiting platform 12c; first portion 128; second portion 129; first portion 1291; second portion 1292; first cover plate 13; first conductive member 131; second groove 1311; second conductive member 132; stress relief groove 133; Second accommodating portion 134; fifth accommodating groove 1341; third end wall 13411; third side wall 13412; second cover plate 14; second pole 15; pressure relief portion 16; avoidance groove 18; first sealing gasket 191; second sealing gasket 192; battery cell assembly 2; electrode assembly 2a; active material coating portion 21; current collector 211; active material layer 212; conductive portion 22; pole ear portion 221; pole ear piece 2211; first folded portion 2212; second folded portion 2213; adapter piece 222; bracket 3; avoidance hole 31; first hole section 311; second hole section 312; guide portion 32; first bracket 33; second bracket 34; shell entry guide surface 35; body portion 36; extension portion 37; third groove 38; positioning groove 39; Inner insulator 4 ; main body 41 ; connection portion 42 ; outer insulator 5 ; outer insulating film 52 ; connection portion 51 ; seal 6 ; first welding portion 71 ; second welding portion 72 ; insulating seal member 8 ; insulator 81 ; seal 82 ; patch 9 . DETAILED DESCRIPTION

[0166] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0167] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0168] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0169] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0170] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0171] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0172] The term "plurality" used in this application refers to two or more (including two).

[0173] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0174] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or battery pack. A battery module generally includes multiple battery cells. A battery pack generally includes a casing for enclosing one or more battery cells or one or more battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0175] For example, a battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to house the cell assembly and electrolyte, and is provided with at least one positive electrode post and at least one negative electrode post. The cell assembly includes one or more electrode assemblies, which are formed by stacking or winding positive and negative electrode sheets and separators.

[0176] The positive electrode sheet generally includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is directly or indirectly coated on the positive electrode current collector. The positive electrode current collector not coated with the positive electrode active material layer protrudes from the positive electrode current collector coated with the positive electrode active material layer. The positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. Multiple positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the stacked multiple positive electrode tabs can be directly welded to the positive electrode column to form an electrical connection. Alternatively, the battery cell assembly may further include a positive electrode adapter. The stacked multiple positive electrode tabs are welded to one end of the positive electrode adapter, and the other end of the positive electrode adapter is welded to the positive electrode column to form an electrical connection between the positive electrode tab and the positive electrode column.

[0177] The negative electrode sheet can generally include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is directly or indirectly coated on the negative electrode current collector. The negative electrode current collector not coated with the negative electrode active material layer protrudes from the negative electrode current collector coated with the negative electrode active material layer. The negative electrode current collector not coated with the negative electrode active material layer serves as a negative electrode tab. Multiple negative electrode tabs are stacked together and electrically connected to the negative electrode column. For example, the multiple stacked negative electrode tabs can be directly welded to the negative electrode column to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter. The multiple stacked negative electrode tabs are welded to one end of the negative electrode adapter, and the other end of the negative electrode adapter is welded to the negative electrode column to form an electrical connection between the negative electrode tab and the negative electrode column. The material of the separator is not limited, and can be, for example, polypropylene or polyethylene.

[0178] At the same time, battery cells primarily rely on the movement of metal ions between the positive and negative electrodes to operate. Taking lithium-ion batteries as an example, the positive electrode current collector can be made of aluminum, the positive electrode active material layer can be made of lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode current collector can be made of copper, and the negative electrode active material layer can be made of carbon or silicon, etc. During the charge and discharge process, Li+ is intercalated and deintercalated back and forth between the two electrodes: during charging, Li+ is deintercalated from the positive electrode and intercalated into the negative electrode through the electrolyte, leaving the negative electrode in a lithium-rich state; during discharge, the opposite occurs.

[0179] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component in new energy vehicles, batteries have high requirements for both safety and cycle life.

[0180] In the related art, during the manufacturing of battery cells, an active material layer is coated on the current collector and then cut to obtain a pole piece consisting of a current collector coated with an active material layer (referred to as an active material coating portion) and a current collector not coated with an active material layer (referred to as a pole tab piece). The positive and negative pole pieces and the separator are then stacked or wound in sequence to obtain an electrode assembly. In the electrode assembly, multiple pole tab pieces are stacked to form a pole tab portion, and the pole tab portion itself forms a conductive portion, or the pole tab portion is connected to a transition piece to form a conductive portion. The active material coating portion and the conductive portion form a battery cell assembly. A pole post is provided on the shell of the battery cell, and the surface of the pole post facing the active material coating portion is the inner end face of the pole post. In the related art, the conductive portion is generally welded to the inner end face of the pole post.

[0181] The inventors discovered that during the assembly of a battery cell, the tab is first welded to the inner end face of the electrode. Since the first welding portion is located on the inner end face of the electrode, close to the interior of the battery cell, metal residue from the welding process is difficult to completely clean, causing the remaining metal residue to fall into the active material coating portion and overlap the electrode pieces of opposite polarity, thereby causing an internal short circuit in the battery cell and reducing the reliability of the battery cell. Moreover, the tab generates high temperatures during the welding process to the electrode. As a result, the high temperature when the tab forms a weld mark will burn the active material coating portion in the shell, causing the active material coating on the active material coating portion to be lost, thereby reducing the performance of the battery cell and not being conducive to extending the service life of the battery cell. On the other hand, during the process of assembling the battery cell, the electrode of a battery cell needs to be welded to the electrode of another battery cell through a busbar. Since high temperatures are also generated during the welding process, the high temperature generated when the electrode and the external busbar are welded will affect the weld between the tab and the electrode, which can easily cause the weld to melt again and become loose, thereby reducing the performance of the battery cell.

[0182] Based on the above considerations, and to address the issues of internal short circuits caused by metal residue generated during welding, damage to the active material coating caused by high temperatures during tab welding, and the impact of the weld between the tab and the tab when the battery cell is welded to the busbar during battery assembly, the inventors, after in-depth research, have designed a battery cell comprising a housing assembly and a cell assembly. The housing assembly comprises a housing and a first terminal. The first terminal comprises a terminal body and a first cover plate. The terminal body is mounted within the housing, and the first cover plate is disposed on the terminal body. The cell assembly comprises an active material coating portion and a conductive portion connected to the active material coating portion. The active material coating portion is housed within the housing, and the conductive portion is connected to the terminal body via a first weld. By positioning the first weld at least partially on the side of the terminal body facing away from the active material coating, metal residue generated during welding can be reduced from entering the battery cell, preventing metal residue from overlapping the positive and negative electrode sheets to a certain extent, thereby reducing the possibility of internal short circuits in the battery cell. By positioning the first weld away from the active material coating portion, the effects of high temperatures generated during welding on the active material coating portion can be reduced, reducing the probability of damage to the active material coating portion. In addition, after the pole body is welded to the conductive part inside the shell, when the battery cell is welded to the busbar component, the first cover plate can shield the first welding part to play a protective role, reduce the impact of the high temperature generated when the pole body and the busbar component are welded on the first welding part, and improve the reliability of the first welding part between the pole body and the conductive part.

[0183] The battery disclosed in the embodiments of the present application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery disclosed in the present application can be used to form the electrical device.

[0184] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0185] For the convenience of description, the following embodiments take the electric device as a vehicle 1000 as an example, and describe in detail the structures of the electric device 1000, the battery 100 and the battery cell 10 of the present application.

[0186] Please refer to Figure 1, which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can serve as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0187] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0188] Please refer to Figure 2, which is an exploded view of the structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 20 and a plurality of battery cells 10, which are intended to be housed within the housing 20. The housing 20 provides assembly space for the battery cells 10 and can have various structures. In some embodiments, the housing 20 can include a first housing body 201 and a second housing body 202. The first housing body 201 and the second housing body 202 overlap each other, and the first housing body 201 and the second housing body 202 together define an assembly space for accommodating the battery cells 10. The second housing body 202 can be a hollow structure with one end open. The first housing body 201 can be a plate-like structure, and the first housing body 201 overlaps the open side of the second housing body 202, so that the first housing body 201 and the second housing body 202 together define an assembly space. Alternatively, the first housing body 201 and the second housing body 202 can each be a hollow structure with one end open, with the open side of the first housing body 201 overlapping the open side of the second housing body 202. Of course, the box body 20 formed by the first box body 201 and the second box body 202 can be in various shapes, such as a cylinder, a cuboid, etc.

[0189] In the battery 100, multiple battery cells 10 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 10. Multiple battery cells 10 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 10 is housed within the housing 20. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 10 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure housed within the housing 20. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 10.

[0190] Please refer to Figure 2, which is a schematic diagram of a partial structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes multiple rows of battery cells 10, which are arranged along a first direction X. Each row of battery cells 10 includes multiple battery cells 10 arranged along a second direction Y. The first direction X and the second direction Y are the length and width directions of the casing 20, respectively, and the first direction X and the second direction Y are perpendicular to each other.

[0191] Each battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 10 can be cylindrical, flat, rectangular or other shapes. For example, in FIG3 , the shape of the battery cell 10 is a rectangular parallelepiped. In related art, a battery cell generally includes a shell and a cell assembly, the shell is provided with a positive electrode column and a negative electrode column, the cell assembly is arranged in the shell, the cell assembly generally includes at least two electrode sheets, and a part is a positive electrode sheet and the rest is a negative electrode sheet, the positive electrode sheet is provided with a positive electrode ear, the negative electrode sheet is provided with a negative electrode ear, and a diaphragm is provided between the positive electrode sheet and the negative electrode sheet, wherein the positive electrode ear is electrically connected to the positive electrode column, the negative electrode ear is electrically connected to the negative electrode column, and the shell is filled with an electrolyte.

[0192] Referring to Figures 3-5 , an embodiment of the present application provides a battery cell 10 comprising a housing assembly 1 and a cell assembly 2. The housing assembly 1 comprises a housing 11 and a first electrode 12. The first electrode 12 comprises a body 1201 and a first cover 13. The body 1201 is mounted on the housing 11, and the first cover 13 is disposed on the body 1201. The cell assembly 2 comprises an active material coating portion 21 and a conductive portion 22 connected to the active material coating portion 21. The active material coating portion 21 is housed within the housing 11, and the conductive portion 22 is connected to the body 1201 via a first weld 71. The shape of the housing 11 varies depending on the type of battery cell 10. The embodiment of the present application is not limited to any type of battery cell 10. For example, when the battery cell 10 is a prismatic battery, the housing 11 is prismatic. When the battery cell 10 is a cylindrical battery, the housing 11 is cylindrical. The embodiments of the present application are described using a square housing 11 as an example.

[0193] The housing 11 is provided with poles, which are used to electrically connect to the battery cell assembly 2 to ensure normal charging and discharging operations of the battery cell 10. Generally, there are at least two poles, specifically at least one positive pole and at least one negative pole. For example, when there are two poles, one is a positive pole and the other is a negative pole, both of which are electrically connected to the positive and negative output positions of the battery cell assembly 2, respectively. For another example, when there are four poles, two can be positive poles and two can be negative poles. In this case, both positive poles are electrically connected to the positive output position of the battery cell assembly 2, and both negative poles are electrically connected to the negative output position of the battery cell assembly 2.

[0194] At the same time, Figure 6 is a structural schematic diagram of the battery cell 10 provided in some embodiments of the present application; Figure 7 is an assembly diagram of the second pole 15, the battery cell assembly 2, and the shell 11 provided in some embodiments of the present application. Please refer to Figures 1 to 7. In the embodiments of the present application, at least one pole among the multiple poles is the first pole 12, and the first pole 12 can be used as both a positive pole and a negative pole.

[0195] Regardless of whether the pole on the shell 11 is the first pole 12 or the second pole 15, the first pole 12 and the second pole 15 can be electrically connected to the battery cell assembly 2 to ensure the normal charging and discharging process of the battery cell 10. Of course, in other embodiments of the present application, the shell assembly 1 can also be provided with only one pole, and it is the first pole 12. The first pole 12 includes two parts, which are insulated and connected, and can be used as the positive pole and the negative pole respectively. To simplify the description, the following mainly introduces the case where all the poles on the shell 11 are the first pole 12 formed with the accommodating portion 121.

[0196] It should be noted that, referring to Figures 6 and 7, when the housing 11 is provided with a second pole 15, a relief groove 18 can be provided between the second pole 15 and the housing 11 as required, so that at least a portion of the conductive portion 22 is accommodated in the relief groove 18. This can also reduce the space occupied by the conductive portion 22 within the housing 11 to a certain extent, which is conducive to improving energy density and improving problems such as short circuits caused by redundant conductive portions 22.

[0197] Please refer to Figures 3 to 7 again. In the embodiment of the present application, the battery cell assembly 2 includes an active material coating portion 21 and a conductive portion 22. The active material coating portion 21 is accommodated in the shell 11. The active material coating portion 21 is the portion of the battery cell assembly 2 coated with active material, which can assist in the deintercalation of metal ions during the charging and discharging process of the battery cell 10. The conductive portion 22 is a metal structure that electrically connects the active material coating portion 21 and the pole, which is not coated with active material. The pole is electrically connected to the active material coating portion 21 through the conductive portion 22 to enable the charging and discharging operations of the battery cell 10 to be carried out.

[0198] It should be noted that in the embodiment of the present application, the active material coating portion 21 is divided into a positive electrode active material coating portion and a negative electrode active material coating portion, the positive electrode active material coating portion includes a portion of the positive electrode current collector coated with a positive electrode active material layer, and the negative electrode active material coating portion includes a portion of the negative electrode current collector coated with a negative electrode active material layer. The conductive portion 22 is divided into a positive electrode conductive portion and a negative electrode conductive portion, the positive electrode conductive portion electrically connects the positive electrode active material coating portion and the positive electrode column, and the negative electrode conductive portion electrically connects the negative electrode active material coating portion and the negative electrode column. It should be noted that the first welding portion 71 is formed in any manner, for example, it can be laser welding, friction welding, ultrasonic welding, and according to factors such as the position, angle or structure of the welding part, vertical welding or inclined welding, etc., as well as lap welding or edge sealing welding, etc. can be selected. Exemplarily, the first welding portion 71 can be a long strip weld mark to improve welding reliability and increase overcurrent performance.

[0199] In some embodiments, the conductive portion 22 is welded to the pole body 1201 from the outside to form a first weld portion 71 therebetween. The conductive portion 22 can be located inside the pole body 1201, or it can pass through a via in the pole body 1201 to overlap the outside of the pole body 1201. When the conductive portion 22 is located inside the pole body 1201, the first weld portion 71 penetrates the pole body 1201 to connect with the conductive portion 22. When the conductive portion 22 overlaps the outside of the pole body 1201, the first weld portion 71 penetrates the conductive portion 22 to connect with the pole body 1201. Exposing the first weld portion 71 outside the pole body 1201 may affect the reliability of the weld mark and the subsequent connection with the busbar. Therefore, a first cover plate 13 is provided to cooperate with the pole body 1201 to cover the first weld portion 71.

[0200] In other embodiments, the conductive portion 22 is welded to the pole body 1201 from the inside to form a first weld 71 therebetween. The conductive portion 22 can be located on the inside of the pole body 1201, or it can pass through a through-hole in the pole body 1201 to overlap the outside of the pole body 1201. When the conductive portion 22 is located on the inside of the pole body 1201, the first weld 71 penetrates the conductive portion 22 to connect with the pole body 1201; when the conductive portion 22 overlaps the outside of the pole body 1201, the first weld 71 penetrates the pole body 1201 to connect with the conductive portion 22. To ensure welding reliability, the first weld 71 is provided through the pole body 1201 during welding to increase weld strength. Exposing the first weld 71 on the outside of the pole body 1201 may affect the reliability of the weld mark and the subsequent connection to the current collector. Therefore, a first cover plate 13 is provided to cooperate with the pole body 1201 to cover the first weld 71.

[0201] In the above technical solution, by positioning the first welding portion 71 at least partially on the side of the electrode body 1201 facing away from the active material coating portion 21, the ingress of metal residue generated during welding into the battery cell 10 can be reduced, to a certain extent preventing the metal residue from overlapping the positive and negative electrode sheets, thereby reducing the possibility of an internal short circuit in the battery cell 10. Furthermore, the first welding portion 71 can be positioned away from the active material coating portion 21. When the electrode body 1201 and the conductive portion 22 are welded at high temperature to form the first welding portion 71, the first welding portion 71, acting as a high-temperature heat source, can be positioned away from the active material coating portion 21. This reduces the impact of the high temperature generated by the welding on the active material coating portion 21, thereby reducing the probability of damage to the active material coating portion 21 and improving the reliability of the battery cell 10. In addition, after the pole body 1201 is welded to the conductive part 22 inside the shell 11, when the battery cell 10 is welded to the busbar component 30, the first cover plate 13 shields the first welding part 71 to play a protective role, reducing the impact of the high temperature generated when the pole body 1201 is welded to the busbar component 30 on the first welding part 71, and improving the connection reliability between the pole body 1201 and the conductive part 22.

[0202] For example, there is a certain probability that the high temperature generated when the pole body 1201 and the busbar component 30 are welded will cause the first welding portion 71 to melt again. At this time, due to the obstruction of the first cover plate 13, the high temperature generated when the pole body 1201 and the busbar component 30 are welded will be weakened when it is transferred to the first welding portion 71, thereby making the first welding portion 71 between the pole body 1201 and the conductive portion 22 less likely to be melted again, thereby improving the reliability of the battery cell 10 during the manufacturing process. In some embodiments, in combination with Figures 8 and 9, the pole body 1201 has a first accommodating groove 12110, the surface of the first pole 12 facing the active material coating portion 21 is the pole inner end face 122, the notch of the first accommodating groove 12110 is formed on the pole inner end face 122, and the first accommodating groove 12110 has a first end wall 12111 and a first side wall 12113, the first end wall 12111 is located on the side of the first side wall 12113 away from the active material coating portion 21, at least part of the conductive portion 22 is accommodated in the first accommodating groove 12110, the first welding portion 71 is provided on the first end wall 12111, the first cover plate 13 cooperates with the pole body 1201, and covers the first welding portion 71.

[0203] Exemplarily, the first receiving groove 12110 is a groove body, which is a groove-like structure with a certain depth. For example, when the first terminal 12 is disposed on the upper end wall of the housing 11 and the terminal inner end surface 122 is the lower surface of the first terminal 12, the first receiving groove 12110 is formed as a receiving groove with a groove opening open downward and the groove wall recessed upward. For another example, when the first terminal 12 is disposed on the lower end wall of the housing 11 and the terminal inner end surface 122 is the upper surface of the first terminal 12, the first receiving groove 12110 is formed as a receiving groove with a groove opening open upward and the groove wall recessed downward.

[0204] In the above technical solution, on the one hand, the first receiving groove 12110 provided on the first terminal 12 can reduce the weight of the first terminal 12 to a certain extent, thereby increasing the weight energy density of the battery cell 10 and the battery 100. On the other hand, because the notch of the first receiving groove 12110 is formed on the terminal inner end surface 122, which is the surface of the first terminal 12 on the side close to the active material coating portion 21, the first receiving groove 12110 can be opened toward the active material coating portion 21, thereby facilitating the insertion of the conductive portion 22 into the first receiving groove 12110 and improving assembly efficiency. Furthermore, this type of first receiving groove 12110 is easier to process, improving production efficiency.

[0205] In addition, the first receiving groove 12110 is easy to be processed into a larger volume, so that it can accommodate more conductive parts 22; at the same time, since the first receiving groove 12110 is open toward the active material coating part 21, the first receiving groove 12110 can also serve as a buffer and temporary storage structure for the electrolyte, so that more electrolyte can be accommodated in the shell 11. Since the battery cell 10 will lose electrolyte during the charging and discharging process, the service life of the battery cell 10 can be extended when there is more electrolyte; and because the first receiving groove 12110 is open toward the active material coating part 21, the first receiving groove 12110 can also serve as a storage and buffer structure for gas production inside the battery cell assembly 2, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0206] In addition, since the first receiving groove 12110 is located on the inner side of the first pole 12, external foreign matter and impurities are not easy to enter the first receiving groove 12110, thereby reducing the impact of external foreign matter and impurities on the battery cell assembly 2, improving the stability and reliability of the battery cell assembly 2, and further improving the stability and reliability of the battery cell 10 and the battery 100.

[0207] Secondly, by positioning the first weld portion 71 between the electrode body 1201 and the conductive portion 22 on the first end wall 12111, the first weld portion 71 can be positioned further away from the active material coating portion 21 when within the first receiving groove 12110, further reducing the impact of the high temperature generated when the electrode body 1201 and the conductive portion 22 are welded to form the first weld portion 71 on the active material coating portion 21. Furthermore, the first receiving groove 12110 not only serves to accommodate at least part of the conductive portion 22, but also allows the groove wall of the first receiving groove 12110 to electrically connect with the conductive portion 22. This simplifies the structure of the first electrode 12, facilitates its processing, and simplifies the structure of the conductive portion 22, reducing redundancy and cost. Furthermore, by welding the first end wall 12111 to the conductive portion 22, the weld area formed by the first weld portion 71 can be relatively large, reducing the difficulty of welding and improving the reliability and stability of the welding, thereby enhancing the performance of the battery cell 10.

[0208] In addition, since the first welding portion 71 is located in the first accommodating groove 12110, it can not only prevent the first welding portion 71 from protruding from the outside of the first pole 12 and occupying the space outside the first pole 12, but also enable the first welding portion 71 to be protected by the first cover plate 13, thereby improving the welding reliability and stability of the conductive portion 22 and the first pole 12.

[0209] In addition, in an embodiment of the present application, the first end wall 12111 is constructed as a closed structure without any perforations, so that the first receiving tank 12110 is isolated from the external space of the shell 11, thereby avoiding the problem of the electrolyte in the shell 11 leaking from the first receiving tank 12110.

[0210] In conjunction with Figures 8 and 9 , in some optional embodiments, the shape of a portion of the conductive portion 22 matches the shape of a portion of the first end wall 12111, and the conductive portion 22 is positioned in a manner that fits the conductive portion 22 and forms an electrical connection therewith, such that the first welding portion 71 between the conductive portion 22 and the first end wall 12111 extends along the length or width of the first end wall 12111. For example, when the first end wall 12111 is planar, a portion of the conductive portion 22 can also be planar and fit against the first end wall 12111, with welding being performed at the fitting location. This increases the welding area, improving the reliability and stability of the welding.

[0211] It is worth noting that the shape of the first end wall 12111 is not limited, and can be, for example, a flat plate, an arc-shaped plate, etc. Specifically, when the first end wall 12111 is a flat plate structure, the first end wall 12111 is arranged at an angle to the axial direction R of the first pole 12. For example, the first end wall 12111 can be a flat plate structure perpendicular to the axial direction R of the first pole 12, or can be an inclined plate structure that is not perpendicular to the axial direction R of the first pole 12, but the inclination direction is not limited.

[0212] Of course, in other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the first end wall 12111 may not extend along the length or width direction of the first end wall 12111. For example, it may also be a plurality of discretely arranged welding points. For example, the conductive portion 22 has a plurality of spaced-apart portions that are respectively welded to the first end wall 12111, which will not be elaborated here.

[0213] In some embodiments, referring to FIG10 , the first end wall 12111 has a first recess 12112, and at least a portion of the first welding portion 71 is located within the first recess 12112. It is understood that the first recess 12112 extends downward away from the active material coating portion 21. For example, at least a portion of the conductive portion 22 can be disposed within the first recess 12112 and connected to the portion of the first end wall 12111 defining the first recess 12112.

[0214] In the above technical solution, on the one hand, the first sink groove 12112 can be used to pre-position and limit the first welding part 71, which is not only conducive to finding the correct position for welding and improving production efficiency, but also conducive to improving the stability and reliability of the conductive part 22, and ensuring the stability and reliability of the battery cell 10 during the charging and discharging process; on the other hand, by arranging the first sink groove 12112 on the first end wall 12111, the local wall thickness of the first end wall 12111 can be locally thinned, which is not only conducive to welding, but also conducive to reducing the weight of the first pole 12 and improving the weight energy density of the battery cell 10.

[0215] In some optional embodiments, a portion of the conductive portion 22 matches the shape of the first side wall 12113 and is disposed in close contact with it. For example, when the first side wall 12113 is curved, a portion of the conductive portion 22 may also be curved and in close contact with the first side wall 12113. The in close contact portion is then welded to extend the first welding portion 71 between the conductive portion 22 and the first side wall 12113 along the first side wall 12113. This increases the welding area, thereby improving the reliability and stability of the welding.

[0216] Of course, the present application is not limited to this. In other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the first side wall 12113 may not extend along the first side wall 12113. For example, it may also be a plurality of discretely arranged welding points. For example, the conductive portion 22 has a plurality of spaced-apart portions that are respectively welded to the first side wall 12113. Details will not be given here.

[0217] It should be noted that the number of first side walls 12113 is not limited and can be determined based on the shape of the first receiving groove 12110, as long as the end of each first side wall 12113 away from the notch of the first receiving groove 12110 is connected to the first end wall 12111. By way of example, when the cross-sectional shape of the first receiving groove 12110 is circular or elliptical, the first end wall 12111 is circular or elliptical, and there is one first side wall 12113 in an annular shape, disposed around the circumferential edge of the first end wall 12111. By way of further example, when the cross-sectional shape of the first receiving groove 12110 is rectangular or racetrack-shaped, the first end wall 12111 is rectangular or racetrack-shaped, and there are four first side walls 12113, each connected to the four sides of the first end wall 12111.

[0218] It should also be noted that the first receiving groove 12110 is not limited to the form defined by the first end wall 12111 and the first side wall 12113. For example, in some embodiments, the first end wall 12111 may not exist. In this case, the end of the notch of each first side wall 12113 away from the first receiving groove 12110 converges together, so that the first receiving groove 12110 is defined only by multiple first side walls 12113. At this time, the conductive part 22 can be electrically connected to the first side wall 12113 to ensure that the charging and discharging process of the battery cell 10 proceeds normally.

[0219] In addition, it is worth noting that in other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the first terminal 12 may not be located within the first receiving groove 12110. For example, the first welding portion 71 between the conductive portion 22 and the first terminal 12 may also be located on the terminal inner end surface 122. In this case, part of the conductive portion 22 is accommodated within the first receiving groove 12110, which can also save space to a certain extent and improve the energy density of the battery cell 10.

[0220] 9 and 10 , in some embodiments, the first pole 12 has a first groove 126 , and a surface of the first pole 12 away from the active material coating portion 21 is an outer end face 123 of the pole. The opening of the first groove 126 is formed on the outer end face 123 of the pole, and the first cover plate 13 covers the opening of the first groove 126 .

[0221] It is understood that the first groove 126 is a groove body, which is a groove-like structure with a certain depth. Moreover, when the first pole 12 is arranged on the upper end wall of the housing 11 and the pole outer end surface 123 is the upper surface of the first pole 12, the first groove 126 is formed as a groove with the groove opening open upward and the groove wall concave downward (i.e., concave toward the square near the battery cell assembly 2). For another example, when the first pole 12 is arranged on the lower end wall of the housing 11 and the pole outer end surface 123 is the lower surface of the first pole 12, the first groove 126 is formed as a groove with the groove opening open downward and the groove wall concave upward (i.e., concave toward the square near the battery cell assembly 2).

[0222] In the above technical solution, on the one hand, since the first pole 12 is provided with the first groove 126, the weight of the first pole 12 can be further reduced, so as to improve the weight energy density of the battery cell 10 and the battery 100; on the other hand, the first groove 126 is located on the outside of the first pole 12, that is, it is open toward the side of the first pole 12 away from the interior of the shell 11. The first groove 126 can be used to accommodate or install structural components of the battery 100 that electrically connect the various battery cells 10, so as to make full use of the space in the first pole 12 and improve the space utilization and volume energy density of the battery 100; by providing the first groove 126, the first cover plate 13 is covered with the notch of the first groove 126, which facilitates the welding of the first cover plate 13 and improves assembly efficiency.

[0223] In addition, since the first electrode 12 has both the first receiving groove 12110 and the first groove 126, the first groove 126 is located on the side of the first receiving groove 12110 away from the active material coating portion 21, and the first groove 126 is open in a direction away from the first receiving groove 12110. This facilitates laser welding of the conductive portion 22 to the first end wall 12111 through the first groove 126 from the outside of the first electrode 12, that is, from the side of the first electrode 12 away from the active material coating portion 21, thereby facilitating electrical connection between the conductive portion 22 and the first electrode 12 through external welding. In other words, the above-mentioned structural arrangement facilitates external welding of the first electrode 12 and the conductive portion 22 through the first groove 126, facilitates the processing and manufacturing of the battery cell 10, and can save processing and manufacturing costs.

[0224] Furthermore, in order to conveniently and effectively weld the conductive part 22 to the groove wall of the first receiving groove 12110 through the first groove 126, and improve the welding reliability of the conductive part 22 to the groove wall of the first receiving groove 12110, in an embodiment of the present application, the part between the first groove 126 and the first receiving groove 12110 can be laser welded to the conductive part 22, that is, the spacer part 127 shown in Figure 10 can be laser welded to the conductive part 22 to achieve electrical connection between the battery cell assembly 2 and the first pole 12. The thickness of the spacer 127 of the first pole 12 located between the first groove 126 and the first receiving groove 12110 is relatively thin. The spacer 127 isolates the first groove 126 and the first receiving groove 12110. The side wall of the spacer 127 close to the active material coating part 21 can be used as the first end wall 12111. When the conductive part 22 needs to be welded to the first end wall 12111, since the thickness of the spacer 127 is relatively thin, it is conducive to welding the conductive part 22 and the first end wall 12111 through the first groove 126, thereby improving the convenience and reliability of welding.

[0225] In some embodiments, the first receiving groove 12110 can be configured with a cross-sectional shape in which the length is greater than the width, such as a rectangle, an ellipse, a racetrack, or the like. The first weld portion 71 formed by welding the conductive portion 22 to the first electrode 12 can be a long, strip-shaped weld mark parallel to the length of the first receiving groove 12110, thereby improving welding reliability and enhancing current flow performance. For example, when the first weld portion 71 formed by welding the conductive portion 22 to the first end wall 12111 is a long, strip-shaped weld mark, the width of the weld mark can be greater than or equal to 6 mm, and the distance between the weld mark and the first side wall 12113 can be greater than or equal to 1 mm, thereby ensuring welding convenience and reliability while also ensuring the current flow capacity of the battery cell 10.

[0226] 9 , by providing a first cover plate 13 that covers the first groove 126, the first electrode 12 can be indirectly electrically connected to the busbar 30 through the first cover plate 13. By adjusting the position and structure of the first cover plate 13, the electrical connection between the first cover plate 13 and the busbar 30 is more convenient and the electrical connection area is larger. Thus, the provision of the first cover plate 13 facilitates the electrical connection between adjacent battery cells 10 within the battery 100. Furthermore, since the location where the battery cells 10 are electrically connected is located on the first cover plate 13, the first weld 71 between the conductive portion 22 and the first electrode 12 can be separated by the first groove 126, resulting in less interference between the two and further improving the stability and reliability of the battery cells 10.

[0227] It should be noted that the specific structure of the battery cell assembly 2 of the embodiment of the present application is not limited, for example, it may include but is not limited to the following two implementation methods.

[0228] In some embodiments, in combination with Figures 9-11, the active material coating portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211, the conductive portion 22 includes a pole ear portion 221 electrically connected to the current collector 211, the pole ear portion 221 includes a plurality of pole ear sheets 2211, the plurality of pole ear sheets 2211 converge near the current collector 211 (that is, gather in a direction approaching each other) to form a first gathering portion 2212, the plurality of pole ear sheets 2211 converge and connect at a position away from the current collector 211 to form a second gathering portion 2213, the first gathering portion 2212 connects the second gathering portion 2213 and the active material coating portion 21, at least a portion of the second gathering portion 2213 is accommodated in the first accommodating groove 12110, and the second gathering portion 2213 is connected to the first end wall 12111 through the first welding portion 71.

[0229] In the above technical solution, the plurality of tabs 2211 are merely brought together (i.e., gathered in a direction approaching each other) but not connected when forming the first gathered portion 2212, whereas the plurality of tabs 2211 are not only brought together but also connected into an integrated structure when forming the second gathered portion 2213. For example, the plurality of tabs 2211 may be connected into an integrated plate structure by welding (e.g., ultrasonic welding) to form the second gathered portion 2213, but the present application is not limited thereto. For example, the plurality of tabs 2211 may also be brought together and connected to form the second gathered portion 2213 by bonding with conductive adhesive, etc., which will not be described in detail here.

[0230] It should be noted that in the embodiments of the present application, the tabs 2211 are divided into positive electrode tabs 2211 and negative electrode tabs 2211. The positive electrode tabs 2211 that need to be gathered together are stacked together and ultrasonically pre-welded to form the positive electrode second gathered portion 2213. This can reduce the gaps between layers, allowing the fluffy multiple positive electrode tabs 2211 to form a sheet structure with a certain degree of rigidity. Similarly, the negative electrode tabs 2211 that need to be gathered together are stacked together and ultrasonically pre-welded to form the negative electrode second gathered portion 2213. This can reduce the gaps between layers, allowing the fluffy multiple negative electrode tabs 2211 to form a sheet structure with a certain degree of rigidity.

[0231] In the above technical solution, the phrase "a plurality of electrode tabs 2211 converge at positions close to the current collector 211 to form a first gathered portion 2212, and a plurality of electrode tabs 2211 converge and connect at positions away from the current collector 211 to form a second gathered portion 2213" is intended to explain that, along the extension direction of the electrode tab 2211, the first gathered portion 2212 and the second gathered portion 2213 are sequentially arranged in a direction away from the current collector 211, and the specific positions of the first gathered portion 2212 and the second gathered portion 2213 are not limited, i.e., there is no requirement for the first gathered portion 2212 to be close to the current collector 211, nor for the second gathered portion 2213 to be far from the current collector 211. In some optional examples, the current collector 211 and the electrode tab 2211 may be an integral part, such as an integrally formed aluminum foil for a positive electrode tab, or an integrally formed copper foil for a negative electrode tab, and so on.

[0232] In the above technical solution, since the pole ear portion 221 includes a second gathered portion 2213 formed by converging and connecting multiple pole ear sheets 2211, at least a portion of the second gathered portion 2213 is accommodated in the first accommodating groove 12110, which facilitates the connection between the conductive portion 22 and the first pole 12, can fully utilize the space of the first pole 12, and improve the volume energy density of the battery cell 10.

[0233] 9-11 , in a first embodiment, at least a portion of the second folded portion 2213 is accommodated in the first accommodating groove 12110 , thereby making more effective use of the space within the first pole 12 and further reducing the space occupied by the pole ear portion 221 within the shell 11 to accommodate a larger active material coating portion 21 , thereby increasing the volume energy density of the battery cell 10 , and further reducing the redundancy of the pole ear portion 221 within the shell 11 , thereby further reducing the probability of short circuit between the pole ear portion 221 and the active material coating portion 21 .

[0234] In this embodiment, the second gathered portion 2213 is connected to the first end wall 12111 via the first welding portion 71. For example, in conjunction with FIG9 , when the second gathered portion 2213 is welded to the first end wall 12111 via the first welding portion 71, such as when the second gathered portion 2213 is welded (e.g., laser welded) to the first end wall 12111, the structure of the battery cell assembly 2 can be simplified, parts can be reduced, the assembly process can be simplified, and assembly efficiency can be improved. The first welding portion 71 between the second gathered portion 2213 and the first end wall 12111 can extend along the length direction or width direction of the first end wall 12111. Furthermore, the first end wall 12111 has a first recessed groove 12112, and the first welding portion 71 between the second gathered portion 2213 and the first end wall 12111 can also be located within the first recessed groove 12112, etc. The corresponding technical effects can be referred to the description of the above embodiment and will not be elaborated here.

[0235] In conjunction with Figure 10, in some embodiments, the active material coating portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211, the conductive portion 22 includes a pole ear portion 221 and a transfer piece 222, the pole ear portion 221 includes a plurality of pole ear pieces 2211, the plurality of pole ear pieces 2211 converge at a position close to the current collector 211 to form a first gathering portion 2212, the plurality of pole ear pieces 2211 converge at a position away from the current collector 211 and are connected to form a second gathering portion 2213, the first gathering portion 2212 connects the second gathering portion 2213 and the active material coating portion 21, the transfer piece 222 is connected to the second gathering portion 2213, at least a portion of the transfer piece 222 is accommodated in the first accommodating groove 12110, and the transfer piece 222 is connected to the first end wall 12111 through the first welding portion 71.

[0236] In the above technical solution, the active material coating portion 21 can be electrically connected to the first electrode 12 through the first gathered portion 2212, the second gathered portion 2213, and the adapter plate 222 in sequence. The location where the conductive portion 22 is electrically connected to the first electrode 12 is located on the adapter plate 222. For example, the electrical connection can be achieved by welding (e.g., laser welding) the adapter plate 222 to the first electrode 12. In addition, the adapter plate 222 and the tab 2211 are two separate components and are connected by welding (e.g., ultrasonic welding).

[0237] In the above technical solution, on the one hand, by at least partially accommodating the adapter plate 222 within the first accommodating groove 12110, the space within the first electrode 12 can be more fully utilized, further reducing the space occupied by the conductive portion 22 within the housing 11, thereby improving the volumetric energy density of the battery cell 10. On the other hand, by using the adapter plate 222 and the first welding portion 71 to achieve indirect electrical connection between the second gathered portion 2213 and the first electrode 12, the adapter plate 222 can be welded to the first electrode 12 at a location that avoids the second gathered portion 2213. This ensures a secure weld between the adapter plate 222 and the first electrode 12, reduces the risk of weld cracking, and further improves the reliability and stability of the battery cell 10. Furthermore, the electrical connection between the first electrode 12 and the tab 2211 via the adapter plate 222 simplifies the structure of the tab 2211.

[0238] The connection method and location of the first welding portion 71 between the adapter plate 222 and the first pole 12 are not limited. For example, the first welding portion 71 between the adapter plate 222 and the first pole 12 can be located on the first end wall 12111 and / or the first side wall 12113. Furthermore, the first welding portion 71 between the adapter plate 222 and the first end wall 12111 can extend along the length or width of the first end wall 12111. Furthermore, the first end wall 12111 has a first recessed groove 12112, and the first welding portion 71 between the adapter plate 222 and the first end wall 12111 can be located within the first recessed groove 12112. The corresponding technical effects can be referred to the description of the above embodiment and are not further elaborated here. When the first welding portion 71 between the adapter plate 222 and the first pole 12 is located on the first end wall 12111 and / or the first side wall 12113, since at least part of the adapter plate 222 is accommodated in the first accommodating groove 12110, the structure of the adapter plate 222 can be simplified, redundancy can be reduced, and costs can be lowered.

[0239] 9-11 , in some embodiments, at least a portion of the first gathered portion 2212 is accommodated within the first accommodating groove 12110. In the above technical solution, at least a portion of the first gathered portion 2212 of the electrode ear 221 is accommodated within the first accommodating groove 12110, thereby more fully utilizing the space within the first electrode column 12 and further reducing the space occupied by the electrode ear 221 within the housing 11 to accommodate a larger active material coating portion 21, thereby improving the volumetric energy density of the battery cell 10. Furthermore, the redundancy of the electrode ear 221 within the housing 11 can be further reduced, further reducing the probability of short circuit between the electrode ear 221 and the active material coating portion 21.

[0240] 10-11 , in a second embodiment, the active material coating portion 21 includes a current collector 211 and an active material layer 212 disposed on the current collector 211. The conductive portion 22 includes a tab portion 221 and a transition piece 222. The tab portion 221 includes a plurality of tabs 2211 electrically connected to the current collector 211. The plurality of tabs 2211 converge near the current collector 211 to form a first gathered portion 2212. The plurality of tabs 2211 converge and connect to form a second gathered portion 2213 away from the current collector 211. The transition piece 222 is electrically connected to the second gathered portion 2213. When the accommodating portion 121 includes a first accommodating groove 12110, at least a portion of the transition piece 222 can be accommodated in the first accommodating groove 12110 and electrically connected to the first electrode 12.

[0241] In the above technical solution, compared with the solution in the first embodiment including the adapter plate 222, in the second embodiment, at least a portion of the adapter plate 222 is accommodated in the first accommodating groove 12110, but the relative position of the pole ear portion 221 and the first accommodating groove 12110 is not limited, that is, at least a portion of the pole ear portion 221 can be accommodated in the first accommodating groove 12110, and the pole ear portion 221 can also be completely located outside the first accommodating groove 12110, thereby meeting different structural design requirements.

[0242] In the above technical solution, by accommodating at least a portion of the adapter plate 222 within the first accommodating groove 12110, the adapter plate 222 can occupy the space within the first pole 12, thereby reducing the space occupied by the adapter plate 222 within the housing 11 to accommodate a larger active material coating portion 21, thereby improving the volume energy density of the battery cell 10. It can also reduce the probability of short circuiting between the adapter plate 222 and the active material coating portion 21, reducing the risk of short circuiting of the battery cell assembly 2, and thus improving the stability and reliability of the battery cell 10. In addition, accommodating at least a portion of the conductive portion 22 within the accommodating portion 121 is also conducive to stabilizing and limiting the conductive portion 22, thereby improving the stability of the conductive portion 22, thereby facilitating welding of the conductive portion 22 to the first pole 12, and improving assembly efficiency.

[0243] In addition, by using the adapter plate 222 to achieve indirect electrical connection between the second retracted portion 2213 and the first pole 12, the adapter plate 222 can be welded to the first pole 12 at a position avoiding the second retracted portion 2213, so that the welding between the adapter plate 222 and the first pole 12 is firm, the risk of welding cracking is small, and the reliability and stability of the battery cell 10 can be further improved; at the same time, by electrically connecting the first pole 12 and the pole tab 2211 through the adapter plate 222, the structure of the pole tab 2211 can also be simplified.

[0244] For example, in some optional embodiments, such as the first embodiment above or the third embodiment below, when the second gathered portion 2213 is directly electrically connected to the first electrode 12, the conductive portion 22 may be composed solely of the positive electrode tab and the negative electrode tab in each electrode assembly 2a. For example, in other embodiments, such as the first or second embodiment above, or the third or fourth embodiment below, when the second gathered portion 2213 is indirectly electrically connected to the first electrode 12 via the adapter 222, the conductive portion 22 may be composed simultaneously of the positive electrode tab and the negative electrode tab in each electrode assembly 2a and each adapter 222.

[0245] In some embodiments, when the battery cell assembly 2 includes two electrode assemblies 2a, the tabs 2211 of the two electrode assemblies 2a can be folded together, and the folding position is located at the center between the two electrode assemblies 2a to form a symmetrical folded form (for example, as shown in Figures 11 and 12(a)). Alternatively, in some other embodiments, when the tabs 2211 of the two electrode assemblies 2a are folded together, the folding position can also be biased towards one of the electrode assemblies 2a to form an asymmetrical folded form (for example, as shown in Figures 12(b) and 12(c)). In addition, the electrode assembly 2a can be in a full-tab form (for example, as shown in Figure 12(a)) or a half-tab form (for example, as shown in Figures 11, 12(b) and 12(c)).

[0246] Of course, the present application is not limited to this, and the tabs 2211 of the same polarity of the two electrode assemblies 2a may not be folded together. For example, the tabs 2211 of each electrode assembly 2a may be folded separately according to the positive and negative poles, that is, the positive tab of one electrode assembly 2a is folded separately, and the positive tab of the other electrode assembly 2a is also folded separately. This is not detailed here.

[0247] It should be noted that the accommodating portion 121 of the embodiment of the present application is not limited to having the form of the first accommodating groove 12110. For example, some other optional embodiments will be given later.

[0248] 8 , in some embodiments, the housing 11 has a mounting hole 113 , and the first pole 12 is mounted in the mounting hole 113 ; along the axial direction of the first pole 12 , a depth H1 of the first accommodating groove 12110 is greater than or equal to a minimum distance H2 from the inner end surface 122 of the pole to the mounting hole 113 .

[0249] It should be noted that the specific shape of the first receiving groove 12110 is not limited and can be regular or irregular, such as a cylindrical groove with a rectangular, elliptical, or racetrack-shaped cross-section, a trapezoidal groove with a rectangular cross-section and gradually changing cross-sectional dimensions, a hemispherical groove with a circular cross-section and gradually changing cross-sectional dimensions, or a hemispherical groove with an elliptical cross-section and gradually changing cross-sectional dimensions, etc. Therefore, the depth H1 of the first receiving groove 12110 refers to the maximum depth of the first receiving groove 12110 along the axial direction R of the first pole 12.

[0250] Since in the axial direction R of the first pole 12, the depth H1 of the first accommodating groove 12110 is greater than or equal to the minimum distance H2 from the inner end face 122 of the pole to the mounting hole 113, the volume of the first pole 12 can be fully utilized, so that the first accommodating groove 12110 has a larger depth, which is conducive to accommodating more conductive parts 22, and thus can greatly reduce the space occupied by the conductive parts 22 in the shell 11, further improve the energy density of the battery cell 10, and further reduce the redundancy of the conductive parts 22 in the shell 11; at the same time, since the first accommodating groove 12110 has a larger depth, it can also accommodate the gas production of the battery cell assembly 2, ensure the reliability and stability of the battery cell 10, and can also accommodate more electrolyte to ensure the service life of the battery cell 10.

[0251] It should be noted that the volume of the first receiving groove 12110 is not limited. For example, in some specific examples, the volume of the first receiving groove 12110 that can be used to accommodate the conductive portion 22 (referred to as the first volume V1) can be greater than or equal to 298 mm. 3 , so that the first receiving groove 12110 can have sufficient space to accommodate the conductive part 22 and facilitate welding of the conductive part 22 and the first pole 12. When the first volume V1 of the first receiving groove 12110 is less than 298mm 3 When the conductive portion 22 is not contained in the first receiving groove 12110 , the capacity of the conductive portion 22 to be contained in the first receiving groove 12110 is relatively weakened, and the difficulty of welding the conductive portion 22 and the first pole 12 is increased.

[0252] It is worth noting that the first volume V1 of the first receiving groove 12110 is the difference between the total volume V2 of the first receiving groove 12110 and the volume of the first receiving groove 12110 required to accommodate other components except the conductive part 22 (recorded as the second volume V3), that is, V1 = V2 - V3. It is understandable that when the first receiving groove 12110 does not need to accommodate other components except the conductive part 22, the second volume V3 can be 0mm. 3 For example, the first volume V1 of the first receiving tank 12110 can be 300 mm 3 -1500mm 3 , for example, 300mm 3 , 400mm 3 , 500mm 3 , 600mm 3 , 700mm 3 , 800mm 3 , 1000mm 3 , 1200mm 3 , 1400mm 3 , 1500mm 3 etc.

[0253] Optionally, in combination with Figure 8, the first accommodating groove 12110 can be set corresponding to the position of the mounting hole 113, or in other words, on the projection plane perpendicular to the axial direction R of the first pole 12, the orthographic projection of the first accommodating groove 12110 is located within the orthographic projection range of the mounting hole 113, so that the first accommodating groove 12110 can have a larger depth to accommodate more conductive parts 22, thereby reducing the space occupied by the conductive parts 22 in the shell 11 to a greater extent.

[0254] In some embodiments, in combination with Figure 13, the pole body 1201 has a second accommodating groove 12120, the surface of the pole body 1201 away from the active material coating part 21 is the pole outer end face 123, the notch of the second accommodating groove 12120 is formed on the pole outer end face 123, the second accommodating groove 12120 has a second end wall 12121 close to the active material coating part 21, the first welding part 71 is provided on the second end wall 12121, the first cover plate 13 cooperates with the pole body 1201, and covers the notch of the second accommodating groove 12120.

[0255] It is understood that the second receiving groove 12120 is a groove body, which is a groove-like structure with a certain depth. For example, when the first pole 12 is disposed on the upper end wall of the housing 11 and the pole outer end surface 123 is the upper surface of the first pole 12, the second receiving groove 12120 is formed as a receiving groove with an upwardly open groove opening and a downwardly recessed groove wall. For another example, when the first pole 12 is disposed on the lower end wall of the housing 11 and the pole outer end surface 123 is the lower surface of the first pole 12, the second receiving groove 12120 is formed as a receiving groove with a downwardly open groove opening and an upwardly recessed groove wall.

[0256] In the above technical solution, combined with Figure 13, on the one hand, the first electrode 12 is provided with a second receiving groove 12120, which can reduce the weight of the first electrode 12 to a certain extent, so as to improve the weight energy density of the battery cell 10 and the battery 100; on the other hand, since the notch of the second receiving groove 12120 is formed on the electrode outer end surface 123, and the electrode outer end surface 123 is the surface of the first electrode 12 away from the active material coating portion 21, the second receiving groove 12120 can be open in a direction away from the active material coating portion 21. In this way, when at least a portion of the conductive portion 22 is accommodated in the second receiving groove 12120, the conductive portion 22 can be easily stored and sorted through the notch of the second receiving groove 12120, and the electrical connection operation between the conductive portion 22 and the first electrode 12 can be easily achieved through the notch of the second receiving groove 12120, thereby reducing the production difficulty of the battery cell 10 and improving the production efficiency of the battery cell 10.

[0257] The first welding portion 71 is provided on the second end wall 12121. That is, the second receiving groove 12120 not only accommodates at least a portion of the conductive portion 22, but the groove wall of the second receiving groove 12120 also functions to weld to the conductive portion 22. This simplifies the structure of the first terminal 12 and facilitates processing of the first terminal 12. Furthermore, the opening direction of the second receiving groove 12120 allows for easy welding of the conductive portion 22 to the groove wall of the second receiving groove 12120 through the groove of the second receiving groove 12120, reducing the difficulty of welding. Furthermore, utilizing the groove wall of the second receiving groove 12120 to achieve a welded connection with the conductive portion 22 allows for a relatively large weld area formed by the first welding portion 71 between the conductive portion 22 and the first terminal 12, thereby improving the reliability and stability of the electrical connection and, in turn, enhancing the performance of the battery cell 10.

[0258] In addition, since the first welding portion 71 between the conductive portion 22 and the first pole 12 is located in the second accommodating groove 12120, it can not only avoid the position of the first welding portion 71 protruding from the outside of the first pole 12 and occupying the space outside the first pole 12, but also the position of the first welding portion 71 can be protected by the first pole 12, thereby improving the reliability and stability of the electrical connection between the conductive portion 22 and the first pole 12.

[0259] In conjunction with Figures 13 and 14 , in some embodiments, the shape of a portion of the conductive portion 22 matches the shape of a portion of the second end wall 12121, and the conductive portion 22 is positioned in a manner such that welding is performed, so that the first welding portion 71 between the conductive portion 22 and the second end wall 12121 extends along the length or width of the second end wall 12121. For example, when the second end wall 12121 is planar, a portion of the conductive portion 22 can also be planar and fit against the second end wall 12121, with welding performed at the fitting location. This can increase the area of ​​the first welding portion 71, improving the reliability and stability of welding.

[0260] It is worth noting that the shape of the second end wall 12121 is not limited, and can be, for example, a flat plate or an arc-shaped plate structure. When the second end wall 12121 is a flat plate structure, it is arranged at an angle to the axial direction R of the first pole 12. For example, it can be a flat plate structure perpendicular to the axial direction R of the first pole 12, or it can be an inclined flat plate structure that is not perpendicular to the axial direction R of the first pole 12, but the inclination direction is not limited.

[0261] In the above technical solution, since the conductive part 22 is connected to the pole body 1201 through the first welding part 71, there is welding slag at the first welding part 71, and the first welding part 71 is arranged on the second end wall 12121, so that the welding slag can be kept away from the active material coating part 21, thereby reducing the amount of welding slag entering the interior of the shell 11. On the other hand, the first cover plate 13 blocks the first welding part 71, which can protect the first welding part 71. In this way, the welding slag or part of the welding slag falling on the first welding part 71 can be blocked by the first cover plate 13, further reducing the amount of welding slag entering the interior of the shell 11. By reducing the welding slag entering the shell 11 twice, the risk of short circuit inside the battery cell 10 due to the presence of welding slag can be greatly reduced, thereby improving the reliability of the battery cell 10.

[0262] In addition, when the battery cell 10 transmits electricity to the outside, the pole body 1201 needs to be electrically connected to the busbar component 30. At this time, the pole body 1201 is welded to the busbar component 30. In this case, since the first cover plate 13 can block the first welding portion 71, the busbar component 30 will not contact the first welding portion 71, or it can be understood that the busbar component 30 and the first welding portion 71 can be isolated from each other, which can also reduce the influence of the first welding portion 71 on other welding positions on the pole body 1201.

[0263] In some embodiments, referring to FIG55 , the conductive portion 22 is located on the side of the second end wall 12121 facing the active material coating portion 21. In this case, the first welding portion 71 is located on the side of the second end wall 12121 facing the active material coating portion 21. In this case, the distance between the first welding portion 71 and the surface of the pole body 1201 located outside the housing 11 is relatively large, which can reduce the impact of high temperatures generated during welding of the pole body 1201 and the current collecting component 30 on the first welding portion 71.

[0264] In conjunction with Figure 13, in some embodiments, the second receiving groove 12120 is connected to the interior of the shell 11 through the first through-hole 12130, the conductive part 22 is passed through the first through-hole 12130 and is at least partially accommodated in the second receiving groove 12120, and the conductive part 22 is at least partially arranged on the side of the second end wall 12121 away from the active material coating part 21.

[0265] It can be understood that since the second receiving tank 12120 can be connected to the interior of the shell 11 through the first perforation 12130, the second receiving tank 12120 can also serve as a buffer and temporary storage structure for the electrolyte, so that more electrolyte can be accommodated in the shell 11. Since the battery cell 10 will lose electrolyte during the charging and discharging process, when there is more electrolyte, the service life of the battery cell 10 can be extended; and also because the second receiving tank 12120 can be connected to the interior of the shell 11 through the first perforation 12130, the second receiving tank 12120 can also serve as a receiving and buffer structure for gas production inside the battery cell assembly 2, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0266] It is worth noting that when the receiving portion 121 has the second receiving groove 12120 and the conductive portion 22 is passed through the first through hole 12130 and at least partially received in the second receiving groove 12120 , the welding position of the conductive portion 22 and the first pole 12 is not limited.

[0267] Exemplarily, when the conductive portion 22 is passed through the first through-hole 12130 and is at least partially accommodated in the second accommodating groove 12120 , in some embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the first pole 12 is located on the hole wall of the first through-hole 12130 formed by the first pole 12 .

[0268] In the above technical solution, the first welding portion 7 between the conductive portion 22 and the first pole 12 is arranged on the hole wall of the first through-hole 12130, thereby facilitating the welding operation of the conductive portion 22 and the first pole 12 through the second accommodating groove 12120. Moreover, when the welding area between the conductive portion 22 and the first pole 12 is large, the welding of the conductive portion 22 and the first pole 12 can be utilized to achieve the sealing of the first through-hole 12130, thereby saving sealing costs, reducing electrolyte leakage, and saving sealing parts.

[0269] Specifically, the conductive part 22 can be welded to the hole wall of the first through-hole 12130 at the position where the first through-hole 12130 is connected to the second receiving groove 12120, so as to facilitate the operation. Moreover, by controlling the weld mark, the weld mark and the conductive part 22 can be used to seal the first through-hole 12130 to improve the problem of the electrolyte in the shell 11 leaking from the first through-hole 12130.

[0270] As another example, when the conductive portion 22 is passed through the first through-hole 12130 and is at least partially accommodated in the second receiving groove 12120, in other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the first pole 12 may also be located on the wall of the second receiving groove 12120 formed by the first pole 12. This facilitates electrical connection operations. For example, when the conductive portion 22 is welded to the wall of the second receiving groove 12120 formed by the first pole 12, the risk of conductive particles generated by the welding entering the housing 11 and causing a short circuit or other problems can be reduced.

[0271] In some embodiments, in combination with Figures 13 and 14, the second accommodating groove 12120 further has a second side wall 12123, the second side wall 12123 is located on the side of the second end wall 12121 away from the active material coating portion 21, and the second side wall 12123 and the second end wall 12121 are arranged to form the second accommodating groove 12120, the first through hole 12130 is opened on the second end wall 12121, and the second end wall 12121 has a second sinking groove 12122, and at least part of the first welding portion 71 is located in the second sinking groove 12122.

[0272] In the above technical solution, on the one hand, since the first through hole 12130 is opened on the second end wall 12121, it is convenient for the conductive part 22 to extend into the second accommodating groove 12120 through the first through hole 12130, which can simplify the structure of the conductive part 22, reduce the redundancy of the conductive part 22, and reduce the cost of the conductive part 22.

[0273] On the other hand, the portion of the first welding portion 71 located in the second groove 12122 is set to match the shape of the second groove 12122 and is fitted to achieve welding, so that the second groove 12122 can be used to pre-position and limit the first welding portion 71 on the conductive portion 22, which is conducive to finding the correct position for welding, improving production efficiency, and improving the stability and reliability of the welding position, so as to ensure the reliability and stability of the charging and discharging operations of the battery cell 10.

[0274] 13 and 14 , the second end wall 12121 can be a flat plate-shaped structure, with the included angle θ between the second end wall 12121 and the axial direction R of the first electrode 12 being equal to 90°. That is, along the direction from the first through-hole 12130 to the second side wall 12123, the second end wall 12121 is equidistant from the active material coating portion 21. This facilitates welding of the conductive portion 22 to the second end wall 12121.

[0275] For another example, in conjunction with Figure 15, the angle θ between the second end wall 12121 and the axial direction R of the first pole 12 is greater than 90°, that is, along the direction from the first through-hole 12130 to the second side wall 12123, the second end wall 12121 extends obliquely toward the active material coating portion 21. As a result, the extension distance of the conductive portion 22 along the second end wall 12121 can be increased to increase the reliability of the electrical connection. Exemplarily, the angle θ between the second end wall 12121 and the axial direction R of the first pole 12 can be 90°-145°, such as 100°, 110°, 120°, 130°, 140°, etc., thereby making the second end wall 12121 easy to process and convenient for electrical connection with the conductive portion 22, and more fully utilizing the space within the first pole 12 to accommodate the conductive portion 22.

[0276] For another example, in conjunction with Figure 16, the angle θ between the second end wall 12121 and the axial direction R of the first pole 12 is less than 90°, that is, along the direction from the first through-hole 12130 to the second side wall 12123, the second end wall 12121 extends obliquely in a direction away from the active material coating portion 21. As a result, the extension distance of the conductive portion 22 along the second end wall 12121 can be increased to increase the reliability of the electrical connection. Exemplarily, the angle θ between the second end wall 12121 and the axial direction R of the first pole 12 can be 45°-90°, such as 50°, 60°, 70°, 80°, etc., so that on the one hand, the second end wall 12121 can be easily processed and convenient for welding with the conductive portion 22, and on the other hand, the space within the first pole 12 can be more fully utilized to accommodate the conductive portion 22.

[0277] Of course, the present application is not limited to this. In other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the second end wall 12121 may not extend along the length or width direction of the second end wall 12121. It may also be a plurality of discretely arranged points. For example, the conductive portion 22 has a plurality of spaced-apart portions that are respectively welded to the second end wall 12121, which will not be elaborated here.

[0278] Referring again to Figure 14 , regardless of the specific value of the angle θ between the second end wall 12121 and the axial direction R of the first electrode 12, in the embodiments of the present application, when the conductive portion 22 is welded to the second end wall 12121, a second recess 12122 can be provided on the second end wall 12121 as needed. The second recess 12122 is a groove formed by partially sinking the second end wall 12121 toward the end proximal to the active material coating portion. The first weld 71 between the conductive portion 22 and the second end wall 12121 is at least partially located within the second recess 12122.

[0279] In the above technical solution, the portion of the conductive part 22 located in the second groove 12122 is set to match the shape of the second groove 12122 and is fitted to achieve welding, so that the second groove 12122 can be used to pre-position and limit the welding position of the conductive part 22, which is conducive to finding the correct position for welding, improving production efficiency, and improving the stability and reliability of the electrical connection position, so as to ensure the reliability and stability of the charging and discharging operations of the battery cell 10.

[0280] It should be noted that in the embodiment of the present application, a portion of the conductive portion 22 can also be configured to match the shape of the second side wall 12123 and be fitted thereto. For example, when the second side wall 12123 is a curved surface, a portion of the conductive portion 22 can also be a curved surface and fit thereto, and the fitted portion can be welded so that the first welding portion 71 between the conductive portion 22 and the second side wall 12123 extends along the second side wall 12123. In this way, the area of ​​the first welding portion 71 can be increased, thereby improving the reliability and stability of the welding.

[0281] It should also be noted that in other embodiments of the present application, the first welding portion 71 between the conductive portion 22 and the second side wall 12123 may not extend along the second side wall 12123. For example, it may be a plurality of discretely arranged points. For example, the conductive portion 22 has a plurality of spaced-apart portions that are respectively welded to the second side wall 12123, which will not be elaborated here.

[0282] It is understood that the number of second side walls 12123 is not limited and can be determined based on the shape of the second receiving groove 12120. However, it is sufficient that the end of each second side wall 12123 away from the notch of the second receiving groove 12120 is connected to the second end wall 12121. For example, when the cross-sectional shape of the second receiving groove 12120 is circular or elliptical, the second end wall 12121 is circular or elliptical, and there is one second side wall 12123, which is annular and disposed around the circumferential edge of the second end wall 12121. For another example, when the cross-sectional shape of the second receiving groove 12120 is rectangular or racetrack-shaped, the second end wall 12121 is rectangular or racetrack-shaped, and there are four second side walls 12123, each connected to the four sides of the second end wall 12121.

[0283] It should also be noted that the second accommodating groove 12120 is not limited to a form defined by the second end wall 12121 and the second side wall 12123. For example, in some embodiments, in combination with Figure 17, one end of the notch of each second side wall 12123 away from the second accommodating groove 12120 extends to the first through-hole 12130, so that the second accommodating groove 12120 is defined only by multiple second side walls 12123. At this time, the conductive part 22 can be electrically connected to the second side wall 12123.

[0284] In some embodiments, in combination with Figure 29, the active material coating portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211, the conductive portion 22 includes a pole ear portion 221 electrically connected to the current collector 211, the pole ear portion 221 includes a plurality of pole ear sheets 2211, the plurality of pole ear sheets 2211 converge at a position close to the current collector 211 to form a first gathering portion 2212, the plurality of pole ear sheets 2211 converge at a position away from the current collector 211 and are connected to form a second gathering portion 2213, the first gathering portion 2212 connects the second gathering portion 2213 and the active material coating portion 21, at least a portion of the second gathering portion 2213 is accommodated in the second accommodating groove 12120, and the second gathering portion 2213 is connected to the second end wall 12121 through the first welding portion 71.

[0285] In the above technical solution, because the electrode tab portion 221 includes a second gathered portion 2213 formed by the convergence and connection of multiple electrode tabs 2211, at least a portion of the second gathered portion 2213 can be easily accommodated within the second receiving groove 12120, facilitating the assembly of the conductive portion 22 and the first electrode 12. Furthermore, accommodating at least a portion of the second gathered portion 2213 within the second receiving groove 12120 utilizes the space within the first electrode 12, reducing the space occupied by the conductive portion 22 within the housing 11 and improving the volumetric energy density of the battery cell 10.

[0286] In some optional examples, in combination with Figure 29, the position where the first gathering portion 2212 and the second gathering portion 2213 are connected can be set corresponding to the first through-hole 12130, that is, on the projection plane perpendicular to the axial direction R of the first pole 12, the orthographic projection of the position where the first gathering portion 2212 and the second gathering portion 2213 are connected is located within the orthographic projection range of the first through-hole 12130, thereby facilitating the second gathering portion 2213 to extend into the first through-hole 12130 at a shorter distance and enter the second accommodating groove 12120, thereby reducing redundancy and reducing costs.

[0287] It is understood that the folding position of the tab 2211 can be designed based on the position of the first through-hole 12130, for example, by adopting the symmetrical folding method described above or the asymmetrical folding method, so that the position where the first folding portion 2212 and the second folding portion 2213 connect is aligned with the first through-hole 12130. This will not be described in detail here. Furthermore, as mentioned above, when the second folding portion 2213 is formed into a sheet structure using ultrasonic pre-welding, it is easier for the second folding portion 2213 to pass through the first through-hole 12130.

[0288] In some embodiments, in combination with Figure 30, the active material coating portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211, the conductive portion 22 includes a pole ear portion 221 and a transfer piece 222, the pole ear portion 221 is electrically connected to the current collector 211, the pole ear portion 221 includes a plurality of pole ear pieces 2211, the plurality of pole ear pieces 2211 converge at a position close to the current collector 211 to form a first gathering portion 2212, the plurality of pole ear pieces 2211 converge at a position away from the current collector 211 and are connected to form a second gathering portion 2213, the first gathering portion 2212 connects the second gathering portion 2213 and the active material coating portion 21, the transfer piece 222 is connected to the second gathering portion 2213, at least a portion of the transfer piece 222 is accommodated in the second accommodating groove 12120, and the transfer piece 222 is connected to the second end wall 12121 through the first welding portion 71.

[0289] In the above technical solution, by accommodating at least a portion of the adapter plate 222 in the second accommodating groove 12120, the adapter plate 222 can occupy the space in the first pole 12, thereby reducing the space occupied by the adapter plate 222 in the shell 11 to accommodate a larger active material coating part 21, thereby improving the energy density of the battery cell 10, and reducing the probability of short-circuiting between the adapter plate 222 and the active material coating part 21, reducing the risk of short-circuiting the battery cell assembly 2, and improving the stability and reliability of the battery cell 10.

[0290] In addition, by using the adapter plate 222 to achieve indirect electrical connection between the second retracted portion 2213 and the first pole 12, the adapter plate 222 can be welded to the first pole 12 at a position avoiding the second retracted portion 2213, so that the welding between the adapter plate 222 and the first pole 12 is firm, the risk of welding cracking is small, and the reliability and stability of the battery cell 10 can be further improved; at the same time, by electrically connecting the first pole 12 and the pole tab 2211 through the adapter plate 222, the structure of the pole tab 2211 can also be simplified.

[0291] In some embodiments, referring to FIG. 30 , at least a portion of the first folded portion 2212 is received in the second receiving groove 12120 .

[0292] In the above technical solution, by accommodating at least a portion of the first folded portion 2212 and the adapter plate 222 within the second receiving groove 12120, the space within the first terminal 12 can be more fully utilized, further reducing the space occupied by the conductive portion 22 within the housing 11, thereby further improving the volumetric energy density of the battery cell 10. Furthermore, by providing the adapter plate 222 with a sheet structure, the adapter plate 222 can be easily inserted through the first through-hole 12130 and into the second receiving groove 12120.

[0293] In conjunction with Figure 29, in some embodiments, the pole body 1201 has a first accommodating portion 121, the first accommodating portion 121 has a third accommodating groove 12140, the surface of the first pole 12 facing the active material coating portion 21 is the pole inner end face 122, the third accommodating groove 12140 is located on the side of the second accommodating groove 12120 close to the active material coating portion 21, and the notch of the third accommodating groove 12140 is formed on the pole inner end face 122, the third accommodating groove 12140 is connected to the second accommodating groove 12120 through the first through-hole 12130, and at least part of the first retracted portion 2212 is accommodated in the third accommodating groove 12140.

[0294] At this time, a portion of the conductive part 22 is located in the third accommodating groove 12140, while the conductive part 22 is also passed through the first through-hole 12130, and the rest of the conductive part 22 is located in the second accommodating groove 12120, so that the space in the first pole 12 can be more fully utilized and the space occupied by the conductive part 22 in the shell 11 can be reduced.

[0295] It is worth noting that when the conductive portion 22 is connected to the second end wall 12121 or the second side wall 12123 via laser welding, with reference to FIG17 , the angle β between the welded portion of the conductive portion 22 and the axis of the first through-hole 12130 can be set to be greater than 5°. This reduces the risk of laser light entering the housing 11 through the first through-hole 12130 and facilitates the welding operation. Furthermore, when the angle β between the welded portion of the conductive portion 22 and the axis of the first through-hole 12130 is close to 5°, edge welding can be used; the remaining welds can be lap welded.

[0296] In some embodiments, in conjunction with FIG. 27 and FIG. 28 , the housing assembly 1 further includes a second cover plate 14 , which covers the first through hole 12130 and the conductive portion 22 located in the second receiving groove 12120 .

[0297] It is worth noting that when the housing assembly 1 includes the second cover plate 14, the housing assembly 1 may or may not include the first cover plate 13. Furthermore, when the housing assembly 1 includes both the second cover plate 14 and the first cover plate 13, the first cover plate 13 may be a composite of multiple materials or a non-composite of the same material.

[0298] In the above technical solution, at least a portion of the conductive portion 22 is located in the second receiving groove 12120, and the second cover plate 14 covers the conductive portion 22 of this portion. The second cover plate 14 also covers the first perforation 12130, so that when the electrolyte enters the second receiving groove 12120 from the first perforation 12130, the second cover plate 14 can improve the problem of overflow of this portion of the electrolyte from the first pole 12, thereby improving the reliability of the battery cell 10.

[0299] For example, as shown in Figures 27 and 28, when a portion of the conductive portion 22 is sandwiched between the second cover plate 14 and the second end wall 12121, laser welding can be used to weld the portion of the conductive portion 22, the second cover plate 14, and the second end wall 12121 together to improve the reliability of the connection between the first pole 12 and the conductive portion 22. Furthermore, because the second cover plate 14 can compress the conductive portion 22, the second cover plate 14 can be used to improve the stability of the conductive portion 22 within the second receiving groove 12120.

[0300] Referring again to FIG. 13 , in some embodiments, the housing 11 has a mounting hole 113 , the first pole 12 is mounted in the mounting hole 113 , and along the axial direction of the first pole 12 , a depth H3 of the second receiving groove 12120 is greater than or equal to a minimum distance H4 from the pole outer end surface 123 to the mounting hole 113 .

[0301] It should be noted that the specific shape of the second receiving groove 12120 is not limited and can be regular or irregular, such as a cylindrical groove with a rectangular, elliptical, or racetrack-shaped cross-section, a trapezoidal groove with a rectangular cross-section and gradually changing cross-sectional dimensions, a hemispherical groove with a circular cross-section and gradually changing cross-sectional dimensions, or a hemispherical groove with an elliptical cross-section and gradually changing cross-sectional dimensions, etc. It is worth noting that the racetrack shape described herein refers to a shape in which the two short sides of a rectangle are replaced by convex curves, such as the shape shown in Figure 19(b).

[0302] Therefore, the depth H3 of the second receiving groove 12120 refers to the maximum depth of the second receiving groove 12120 along the axial direction R of the first pole 12. Since the depth H3 of the second receiving groove 12120 is greater than or equal to the minimum distance H4 between the pole outer end surface 123 and the mounting hole 113 in the axial direction R of the first pole 12, the volume of the first pole 12 can be fully utilized, resulting in the second receiving groove 12120 having a greater depth, which is conducive to accommodating more conductive portions 22, thereby greatly reducing the space occupied by the conductive portions 22 within the housing 11, further improving the energy density of the battery cell 10, and further reducing the redundancy of the conductive portions 22 within the housing 11. At the same time, due to the greater depth of the second receiving groove 12120, it can also accommodate gassing of the battery cell assembly 2, ensuring the reliability and stability of the battery cell 10, and can also accommodate more electrolyte to ensure the service life of the battery cell 10.

[0303] It should be noted that the volume of the second receiving groove 12120 is not limited. For example, in some specific examples, the volume of the second receiving groove 12120 that can be used to accommodate the conductive portion 22 (recorded as the third volume V4) can be greater than or equal to 298 mm. 3 , so that the second receiving groove 12120 can have sufficient space to accommodate the conductive part 22 and facilitate welding of the conductive part 22 and the first pole 12. When the third volume V4 of the second receiving groove 12120 is less than 298mm 3 When the second receiving groove 12120 has a relatively weaker capacity for the conductive portion 22, the welding difficulty of the conductive portion 22 and the first pole 12 increases. For example, the third volume V4 of the second receiving groove 12120 can be 300mm 3 , 400mm 3 , 500mm 3 , 600mm 3 , 700mm 3 , 800mm 3 , 1000mm 3 etc.

[0304] It is worth noting that the third volume V4 of the second receiving tank 12120 is the difference between the total volume V5 of the second receiving tank 12120 and the volume of the second receiving tank 12120 required to accommodate other components (such as the first cover plate 13 and the second cover plate 14 described herein) other than the conductive portion 22 (recorded as the fourth volume V6), that is, V4 = V5 - V6. For example, in some specific examples, the total volume V5 of the second receiving tank 12120 can be 1400 mm 3 -1500mm 3, so that the second receiving groove 12120 can have more sufficient space to accommodate the conductive part 22 and other components. For example, the total volume V5 of the second receiving groove 12120 can be 1420mm 3 , 1440mm 3 , 1460mm 3 、1480mm 3 、1490mm 3 etc.

[0305] Optionally, in combination with Figure 13, the second accommodating groove 12120 can be set corresponding to the position of the mounting hole 113, or in other words, on the projection plane perpendicular to the axial direction R of the first pole 12, the orthographic projection of the second accommodating groove 12120 is located within the orthographic projection range of the mounting hole 113, so that the second accommodating groove 12120 can have a larger depth to accommodate more conductive parts 22, thereby reducing the space occupied by the conductive parts 22 in the shell 11 to a greater extent.

[0306] In the embodiment of the present application, the shape of the first through-hole 12130 , the number of the first through-hole 12130 , and the relative positional relationship between the first through-hole 12130 and the second receiving groove 12120 are not limited.

[0307] For example, with respect to the shape of the first through-hole 12130, in conjunction with Figures 18 and 19, in an embodiment of the present application, the first through-hole 12130 can be in the form of an elongated strip to match the shape of the sheet-shaped portion of the conductive portion 22, thereby facilitating the passage of the sheet-shaped portion of the conductive portion 22. Furthermore, when the first through-hole 12130 is in the form of an elongated strip, the second receiving groove 12120 can also be configured in a shape where the cross-section is longer than the width, such as a rectangular, elliptical, or racetrack shape. In this case, the length direction of the first through-hole 12130 can be set to coincide with the length direction of the cross-section of the second receiving groove 12120, thereby fully utilizing the space. Furthermore, the weld mark formed by welding the conductive portion 22 to the first electrode 12 can be in the form of an elongated strip parallel to the length direction of the first through-hole 12130, thereby improving welding reliability and enhancing overcurrent performance. Exemplarily, when the conductive part 22 is welded to the second end wall 12121 to form a long strip-shaped weld mark, the width of the weld mark can be greater than or equal to 6 mm, and the distance between the weld mark and the second side wall 12123 can be greater than or equal to 1 mm, so as to ensure the current flow capacity of the battery cell 10 while ensuring the convenience and reliability of welding.

[0308] Regarding the size and number of the first through-holes 12130, in the embodiments of the present application, the size and specific position of the first through-holes 12130 on the second receiving groove 12120 are not limited, and can be designed according to the number of the first through-holes 12130. For example, the width of the first through-hole 12130 can be greater than or equal to 2 mm, which is conducive to the passage of the conductive portion 22. For example, when there is only one first through-hole 12130 on the second receiving groove 12120, in some examples, in conjunction with Figures 18 and 19, the first through-hole 12130 can be centered relative to the second receiving groove 12120. In other examples, in conjunction with Figure 20, the first through-hole 12130 can also be offset relative to the center of the second receiving groove 12120. For example, in some embodiments, in combination with Figure 20, the first through-hole 12130 can be opened at the edge of the second end wall 12121 to be arranged close to the second side wall 12123, so as to increase the available area of ​​the second end wall 12121 and increase the welding area between the conductive part 22 and the second end wall 12121.

[0309] It is understood that after the conductive portion 22 passes through the first through-hole 12130, it will be folded in order to fit the second end wall 12121, but the direction of the folding is not limited. For example, when the first through-hole 12130 is centrally located relative to the second receiving groove 12120, the conductive portion 22 can be folded toward either side of the first through-hole 12130 after passing through the first through-hole 12130 (see Figure 18), thereby appropriately reducing the size of the second receiving groove 12120 and enhancing the structural compactness and structural strength; alternatively, after passing through the first through-hole 12130, the conductive portion 22 can also be folded toward opposite sides simultaneously (see Figure 21) to reduce the thickness of the weld, reduce the welding heat input, and thus reduce problems such as particle splashing.

[0310] For example, when there are multiple first through-holes 12130 provided on the second receiving groove 12120, the length directions of the multiple first through-holes 12130 are arranged in parallel or substantially parallel to make full use of the space. In this case, the folding direction of the conductive portion 22 after passing through the first through-hole 12130 can be set according to the relative positional relationship of the multiple first through-holes 12130. For example, when there are two first through-holes 12130 provided on the second receiving groove 12120 and they are far away from each other (see FIG. 22 ), the two conductive portions 22 passing through the two first through-holes 12130 can be folded in a direction toward each other; and when there are two first through-holes 12130 provided on the second receiving groove 12120 and they are close to each other, the two conductive portions 22 passing through the two first through-holes 12130 can be folded in a direction away from each other.

[0311] It is understandable that when there are multiple first through holes 12130 opened on the second receiving groove 12120 , the number of the first poles 12 can be appropriately reduced, thereby reducing costs and reducing the number of processes.

[0312] In addition, in some embodiments, in combination with Figures 20 and 21, the first perforation 12130 can be centered relative to the active material coating portion 21, but the position of the first perforation 12130 relative to the second accommodating groove 12120 is not limited and can be centered or offset. Since the first perforation 12130 is centered relative to the active material coating portion 21, the conductive portion 22 can be retracted corresponding to the center line position of the active material coating portion 21.

[0313] In some embodiments, with reference to FIG21 , a sealing member 6 may be provided at the first through-hole 12130 to improve the problem of electrolyte in the housing 11 leaking from the first through-hole 12130. The material, shape, and connection method of the sealing member 6 with the first through-hole 12130 are not limited. For example, the sealing member 6 may be a metal member made of the same material as the first pole 12 or the conductive portion 22, which may be welded to the wall surface of the first through-hole 12130 of the first pole 12 to seal the first through-hole 12130. For another example, the sealing member 6 may be a plastic member that is plugged into the first through-hole 12130 to seal the first through-hole 12130. In the embodiments of the present application, all of these may be designed according to actual requirements without limitation.

[0314] Figure 23 is a structural explosion diagram of the battery cell 10 provided in some embodiments of the present application; Figure 24 is a partial cross-sectional schematic diagram of the shell assembly 1 provided in some embodiments of the present application, and Figure 25 is a structural explosion diagram of the shell assembly 1 shown in Figure 24. In combination with Figure 23 and Figure 24, in some embodiments of the present application, when the accommodating portion 121 has the second accommodating groove 12120 of any of the above-mentioned embodiments, optionally, the shell assembly 1 may further include a first cover plate 13, the first cover plate 13 cooperates with the first pole 12, and closes the notch of the second accommodating groove 12120, and the first cover plate 13 is electrically connected to the first pole 12.

[0315] In the above technical solution, by providing the first cover plate 13 to close the notch of the second receiving tank 12120, the electrolyte in the shell 11 can be prevented from leaking from the notch of the second receiving tank 12120. Moreover, since the first cover plate 13 closes the notch of the second receiving tank 12120 and is electrically connected to the first pole 12, the first cover plate 13 can be used to easily realize the indirect electrical connection between the first pole 12 and the busbar component, and it is beneficial to increase the connection area of ​​the electrical connection, thereby helping to reduce the resistance of the electrical connection.

[0316] It is worth noting that the manner and position of the first cover plate 13 and the first terminal 12 are not limited, as long as the first cover plate 13 can seal the notch of the second receiving groove 12120. For example, in some embodiments, with reference to FIG22 , the first cover plate 13 can be welded to the first terminal 12. During processing, the conductive portion 22 can first be passed through the first through-hole 12130 and welded to the wall of the second receiving groove 12120. Then, the first cover plate 13 and the first terminal 12 are welded to close the notch of the second receiving groove 12120.

[0317] In conjunction with Figure 31, in some embodiments, the pole body 1201 is provided with a first accommodating portion 121, the first accommodating portion 121 has a fourth accommodating groove 12150, the fourth accommodating groove 12150 is a groove body, and the groove body is a groove-shaped structure with a certain depth. The surface of the pole body 1201 away from the active material coating portion 21 is the pole outer end face 123, the notch of the fourth accommodating groove 12150 is formed on the pole outer end face 123, the fourth accommodating groove 12150 is connected to the interior of the shell 11 through the second through-hole 12160, the conductive part 22 may not be accommodated in the fourth accommodating groove 12150, for example, the conductive part 22 is provided in the second through-hole 12160, the first welding part 71 is provided on the hole wall of the second through-hole 12160 formed in the first accommodating portion 121, and the first cover plate 13 cooperates with the pole body 1201 and covers the second through-hole 12160.

[0318] In the above embodiment, by providing the fourth receiving groove 12150, the conductive portion 22 can be easily welded to the wall of the second through-hole 12160. In some cases, the welding of the conductive portion 22 to the first electrode 12 can be used to seal the second through-hole 12160. For example, the conductive portion 22 can be welded to the wall of the second through-hole 12160 at the location where the second through-hole 12160 connects to the fourth receiving groove 12150, thereby facilitating the welding process. Furthermore, by controlling the weld mark, the weld mark and the conductive portion 22 can be used to seal the second through-hole 12160, thereby improving the problem of electrolyte leakage from the housing 11 through the second through-hole 12160.

[0319] It should be noted that the specific shape of the fourth accommodating groove 12150 is not limited, and can be a regular shape or an irregular shape, such as a cylindrical groove with a rectangular, elliptical, or runway-shaped cross-section, or a trapezoidal groove with a rectangular cross-section and a gradually changing cross-sectional size, or a hemispherical groove with a circular cross-section and a gradually changing cross-sectional size, or a semi-ellipsoidal groove with an elliptical cross-section and a gradually changing cross-sectional size, etc.

[0320] In the embodiment of the present application, the second through-hole 12160 can be in the form of an elongated strip to match the shape of the sheet-shaped portion of the conductive portion 22, thereby facilitating the passage of the sheet-shaped portion of the conductive portion 22. Furthermore, when the second through-hole 12160 is in the form of an elongated strip, the fourth receiving slot 12150 can also be configured in a shape where the cross-section is longer than the width, such as a rectangular, elliptical, or racetrack shape. In this case, the length direction of the second through-hole 12160 can be aligned with the length direction of the cross-section of the fourth receiving slot 12150, thereby fully utilizing the space.

[0321] It should be noted that the first accommodating portion 121 of the embodiment of the present application is not limited to the above-mentioned form of having at least one accommodating groove. For example, in some other embodiments of the present application, in conjunction with Figure 32, the first accommodating portion 121 may only have a third through-hole 12170, the surface of the first pole 12 facing the active material coating portion 21 is the pole inner end face 122, the surface of the first pole 12 away from the active material coating portion 21 is the pole outer end face 123, the third through-hole 12170 is in the form of a through-hole and passes through the pole inner end face 122 and the pole outer end face 123, and at least a portion of the conductive portion 22 is provided through the third through-hole 12170. The electrical connection position between the conductive portion 22 and the first pole 12 is not limited. For example, the electrical connection position can be located on the hole wall of the first pole 12 forming the third through-hole 12170, or the conductive portion 22 can also pass through the third through-hole 12170 so that the electrical connection position is located on the pole outer end face 123 outside the third through-hole 12170, etc. Furthermore, the shape of the third through-hole 12170 is not limited and can be a regular hole with a uniform cross-section, or a variable cross-section hole with unequal cross-sections, etc. Furthermore, the cross-sectional shape of the third through-hole 12170 is not limited and can be, for example, a long strip shape such as a rectangle, an ellipse, or a racetrack shape, etc., to match the shape of the sheet-like portion of the conductive portion 22, thereby facilitating the insertion of the sheet-like portion of the conductive portion 22 through the third through-hole 12170. This will not be described in detail here.

[0322] In the embodiments of the present application, the first pole 12 can be an integrally formed pole or a composite pole formed in separate parts. Referring to Figures 27 and 28 , in some embodiments, the pole body 1201 includes a first pole portion 124 and a second pole portion 125 made of different materials and electrically connected. The second pole portion 125 is located on a side of the first pole portion 124 away from the active material coating portion 21. The first accommodating portion 121 is provided on the first pole portion 124 or on both the first pole portion 124 and the second pole portion 125. The first welding portion 71 is provided on the first pole portion 124.

[0323] In the above technical solution, by setting the first pole 12 as a composite form composed of different materials, the first pole portion 124 located on the inner side is accommodated and electrically connected to the conductive portion 22, and the second pole portion 125 located on the outer side is electrically connected to the busbar component 30, etc., which is conducive to the assembly and electrical connection of the first pole 12 with related components, reduces the mutual interference between the welding position of the first pole 12 and the conductive portion 22 and the welding position of the first pole 12 and the busbar component 30 of the battery 100, and improves the reliability and stability of the battery cell 10.

[0324] For example, when the material of the conductive part 22 is different from the material of the busbar component 30, the first pole part 124 can be set to the same material as the conductive part 22, and the second pole part 125 can be set to the same material as the busbar component 30, which is conducive to the welding of the second pole part 125 and the busbar component 30, as well as the welding of the first pole part 124 and the conductive part 22, thereby improving the reliability and stability of the electrical connection between the conductive part 22 and the first pole 12, as well as the reliability and stability of the electrical connection between the first pole 12 and the busbar component 30.

[0325] Furthermore, when the first pole 12 is a composite form of the above embodiments and has the second receiving groove 12120 and the first through-hole 12130 of any of the above embodiments, in some embodiments, the housing assembly 1 may also include the second cover plate 14 of any of the above embodiments. In this case, the second cover plate 14 and the first pole portion 124 may be made of the same material, and the first pole portion 124 and the second cover plate 14 may be electrically connected, thereby improving the reliability and stability of the electrical connection between the first pole portion 124 and the second cover plate 14. For example, the first pole portion 124 and the second cover plate 14 may be connected by welding.

[0326] For example, in combination with Figures 27-28, when the first pole 12 is a negative pole, the first pole portion 124 is made of copper, the second pole portion 125 is made of aluminum, and the conduit component 30 is an aluminum sheet, then the second cover plate 14 can be set to copper, and the first cover plate 13 can be set to aluminum. At this time, the second cover plate 14 and the first pole portion 124 are made of the same material and can be effectively welded, the second pole portion 125 and the first cover plate 13 are made of the same material and can be effectively welded, and the first cover plate 13 and the conduit component 30 are made of the same material and can be effectively welded.

[0327] In an embodiment of the present application, when the first accommodating portion 121 has a second accommodating groove 12120, the matching conditions between the battery cell assembly 2 and the second accommodating groove 12120 are not limited according to the different structures of the battery cell assembly 2, and may include, but are not limited to, the following third and fourth embodiments.

[0328] In some embodiments, in combination with Figures 8 and 54, the first cover plate 13 is provided with a second accommodating portion 134, the second accommodating portion 134 has a fifth accommodating groove 1341, the notch of the fifth accommodating groove 1341 is formed on an end face of the first cover plate 13 facing the active material coating portion 12, and the fifth accommodating groove 1341 has a third end wall 13411 and a third side wall 13412, the third end wall 13411 is located on the side of the third side wall 13412 away from the active material coating portion 21, and at least part of the first welding portion 71 is accommodated in the fifth accommodating groove 1341.

[0329] For example, when the outer end face 123 of the first pole 12 does not form an accommodating groove, the outer end face 123 of the pole is a plane. At this time, the first welding portion 71 protrudes from the outer end face 123 of the pole. The first cover plate 13 is provided with a fifth accommodating groove 1341 to accommodate the first welding portion 71, so as to protect the first welding portion 71 and subsequently connect it to the busbar component.

[0330] Of course, the pole body 1201 has a second accommodating groove 12120. When the notch of the second accommodating groove 12120 is formed on the outer end face 123 of the pole, the first cover plate 13 can also be provided with a fifth accommodating groove 1341 to cooperate with the second accommodating groove 12120 to accommodate the first welding portion 71, so as to protect the first welding portion 71 and subsequently connect with the busbar component.

[0331] In the above technical solution, on the one hand, the first cover plate 13 is provided with the fifth receiving groove 1341, which can reduce the weight of the first electrode 12 to a certain extent, so as to improve the weight energy density of the battery cell 10 and the battery 100; on the other hand, since the notch of the fifth receiving groove 1341 is formed on the end face of the first cover plate 13 facing the active material coating portion 12, and the third end wall 13411 is located on the side of the third side wall 13412 away from the active material coating portion 21, the fifth receiving groove 1341 can be open in the direction away from the active material coating portion 21. In this way, when at least a portion of the conductive portion 22 is accommodated in the fifth receiving groove 1341, the first welding portion 71 can be easily accommodated and sorted through the notch of the fifth receiving groove 1341, thereby reducing the production difficulty of the battery cell 10 and improving the production efficiency of the battery cell 10.

[0332] In some embodiments, the first cover plate 13 is electrically connected to the pole body 1201; alternatively, the first cover plate 13 is insulated from the pole body 1201. Specifically, the first cover plate 13 can be electrically connected to the pole body 1201, thereby also contributing to the electrical connection of the busbar 30. This increases the weldable area and facilitates welding between the first pole 12 and the busbar 30. Alternatively, the first cover plate 13 can be electrically insulated from the pole body 1201, in which case the first cover plate 13 primarily serves to protect the first weld 71.

[0333] In some embodiments, as shown in FIG. 26 , the first cover plate 13 includes a first conductive member 131 and a second conductive member 132 made of different materials. The first conductive member 131 cooperates with and is electrically connected to the pole body 1201 , and the second conductive member 132 cooperates with and is electrically connected to the first conductive member 131 .

[0334] In the above technical solution, the first cover plate 13 is configured as a composite form, and the first conductive member 131 is configured to be made of the same material as the first pole 12, thereby facilitating electrical connection between the first conductive member 131 and the first pole 12. For example, the first conductive member 131 can be easily and reliably and stably connected to the first pole 12 through welding. Furthermore, because the second conductive member 132 is made of a different material than the first conductive member 131, it is convenient to utilize the second conductive member 132 to electrically connect to a busbar component made of a different material than the first pole 12. For example, the second conductive member 132 can be easily and reliably and stably connected to a busbar component made of the same material as the second conductive member 132 through welding.

[0335] For example, when the first pole 12 is a negative pole, the first pole 12 is a copper pole, and the current collector is an aluminum sheet, the first conductive member 131 can be set to copper and the second conductive member 132 can be set to aluminum. In this case, the first pole 12 and the first conductive member 131 are made of the same material and can be effectively welded, and the second conductive member 132 and the current collector are made of the same material and can be effectively welded, thereby effectively achieving an indirect electrical connection between the first pole 12 and the current collector through the first cover 13. Moreover, the copper-to-copper welding of the first pole 12 and the first conductive member 131 has good fluidity and is less likely to crack, which helps to improve the sealing effect of the weld.

[0336] It is worth noting that the matching method of the first conductive member 131 and the second conductive member 132 is not limited. In some embodiments, with reference to Figures 24-26, the first conductive member 131 has a second groove 1311, and the second conductive member 132 is embedded in the second groove 1311. The notch of the second groove 1311 is formed on the surface of the first conductive member 131 on the side away from the active material coating portion 21, so that the second conductive member 132 is exposed from the notch of the second groove 1311. Alternatively, in other embodiments, the connection method between the first conductive member 131 and the second conductive member 132 can also be a fastening connection, a snap connection, etc.

[0337] It should also be noted that the "exposed" of the second conductive member 132 by the notch of the second groove 1311 means that the first conductive member 131 does not block the second conductive member 132 at the notch position of the second groove 1311, and the second conductive member 132 is not required to protrude from the notch of the second groove 1311. For example, the second conductive member 132 can be flush with the surface of the first conductive member 131 on the side away from the second accommodating groove 12120, or the second conductive member 132 can protrude from the surface of the first conductive member 131 on the side away from the second accommodating groove 12120.

[0338] In the above technical solution, on the one hand, by embedding the second conductive member 132 within the first conductive member 131, the difficulty of assembling the first and second conductive members 131, 132 can be reduced, improving the stability and convenience of the cooperation between the first and second conductive members 131, 132. Furthermore, the thickness of the first cover plate 13 can be reduced, reducing the space occupied by the first cover plate 13, thereby improving the space utilization of the battery cell 10. Furthermore, because the second conductive member 132 can be exposed from the surface of the first conductive member 131 on the side away from the second receiving groove 12120 through the notch of the second groove 1311, it is convenient to electrically connect the second conductive member 132 to the busbar outside the first terminal 12.

[0339] In addition, since the notch of the second groove 1311 is formed on the surface of the first conductive member 131 on the side away from the second receiving groove 12120, it means that the second groove 1311 is open in the direction away from the active material coating portion 21, so that the portion of the groove wall of the first conductive member 131 used to define the second groove 1311 is located between the second receiving groove 12120 and the second conductive member 132 to separate the second receiving groove 12120 and the second conductive member 132, thereby preventing the electrolyte entering the second groove 1311 from contacting the second conductive member 132, thereby reducing leakage of the electrolyte.

[0340] Of course, in other embodiments, the first cover plate 13 may not be a composite form composed of multiple materials. For example, in other embodiments of the present application, combined with Figure 27, the first cover plate 13 as a whole can also be set to a non-composite form made of the same material, such as for adapting to the positive electrode column, which will not be elaborated here.

[0341] Referring again to Figures 24-26 , in some embodiments, the first cover plate 13 is further embedded in the notch of the second receiving groove 12120. In the above technical solution, by embedding the first cover plate 13 in the second receiving groove 12120, the difficulty of assembling the first cover plate 13 and the first pole 12 can be reduced, the assembly stability of the first cover plate 13 and the first pole 12 can be improved, as well as the reliability and convenience of the connection. In addition, the space occupied by the first cover plate 13 outside the first pole 12 can be reduced. Moreover, because the first cover plate 13 is embedded in the notch of the second receiving groove 12120, there is sufficient space in the second receiving groove 12120 to accommodate the conductive portion 22.

[0342] Of course, in other embodiments of the present application, the cooperation manner of the first cover plate 13 and the first pole 12 is not limited to being embedded in the second receiving groove 12120. The first cover plate 13 can also be directly covered outside the first pole 12, that is, directly covered at the notch of the second receiving groove 12120, so as to facilitate cooperation with the convergence component of the battery 100. This is not limited in this embodiment.

[0343] Referring again to Figures 24-26 , optionally, in an embodiment of the present application, at least a portion of the wall surface at the notch of the second receiving groove 12120 formed by the first pole 12 is a guide bevel 12126, which is used to guide the first cover plate 13 to mate with the notch of the second receiving groove 12120. In the above technical solution, by processing the wall surface at the notch of the second receiving groove 12120 into a guiding bevel, the difficulty of assembling the first cover plate 13 and the second receiving groove 12120 can be reduced, and the efficiency of assembling the first cover plate 13 and the second receiving groove 12120 can be improved. Moreover, when the first cover plate 13 is welded to the guide bevel 12126, the area of ​​the weld can be increased, thereby improving the reliability of the weld connection between the first cover plate 13 and the first pole 12 and alleviating the problems of molten pool collapse or laser penetration into the first pole 12 during welding.

[0344] 24-26 , the second receiving groove 12120 includes a first groove section 12124 and a second groove section 12125 located on a side of the first groove section 12124 closer to the pole outer end surface 123. The cross-sectional area of ​​the second groove section 12125 is larger than that of the first groove section 12124, giving the second receiving groove 12120 a stepped groove shape. Furthermore, a stepped surface 12127 is formed at the junction of the first groove section 12124 and the second groove section 12125. This allows the first cover plate 13, when embedded in the second receiving groove 12120, to be embedded in the second groove section 12125 and supported by the stepped surface 12127.

[0345] In the above technical solution, by setting the second accommodating groove 12120 to a stepped groove form, the first cover plate 13 can be stably fitted in the groove position of the second accommodating groove 12120, thereby improving the connection stability between the first cover plate 13 and the first pole 12, and by limiting the groove depth of the first groove section 12124, there is relatively sufficient space in the second accommodating groove 12120 to accommodate the conductive part 22.

[0346] Furthermore, when the wall surface at the slot of the second accommodating slot 12120 formed by the first pole 12 is a guide slope 12126, the cross-sectional area of ​​the second slot segment 12125 can be set to gradually increase in the direction approaching the outer end face 123 of the pole, so that the side wall of the second slot segment 12125 is formed as a guide slope 12126, thereby facilitating processing and simply and effectively meeting the guidance requirements.

[0347] Referring again to FIG. 24 to FIG. 26 , in some embodiments, the first cover plate 13 has a stress release groove 133 . The stress release groove 133 is located in the outer peripheral area of ​​the first cover plate 13 to assist the first cover plate 13 in stress release.

[0348] In the above technical solution, by providing a stress relief groove 133 on the first cover plate 13, the stress generated during the processing of the first cover plate 13 itself or during the electrical connection between the first cover plate 13 and the first pole 12 can be released, thereby improving the deformation or damage of the first cover plate 13 caused by the stress and other related problems.

[0349] Specifically, when the first cover plate 13 and the second receiving groove 12120 are embedded and welded, the stress relief groove 133 can be used to release the stress generated by the welding, improve the transverse heat conduction, and reduce the probability of damage or deformation of the first cover plate 13. At the same time, when the first cover plate 13 is a composite form including the first conductive member 131 and the second conductive member 132, the stress relief groove 133 can be set on the first conductive member 131 and located in the peripheral area of ​​the second conductive member 132. When the first conductive member 131 and the second receiving groove 12120 are embedded and welded, the stress relief groove 133 can be used to release the stress generated by the welding, improve the transverse heat conduction, and reduce the probability of damage or deformation of the second conductive member 132. Moreover, when the second conductive member 132 and the first conductive member 131 are embedded and welded, the stress relief groove 133 can be used to release the stress generated by the welding, improve the transverse heat conduction, and reduce the probability of deformation of the first conductive member 131, which may result in the first conductive member 131 being unable to be embedded in the second receiving groove 12120.

[0350] 27-28 , in an embodiment of the present application, the housing assembly 1 may further be provided with a second cover plate 14 as required, and the second cover plate 14 covers the first through-hole 12130 and the conductive portion 22 located in the second receiving groove 12120 .

[0351] It is worth noting that when the housing assembly 1 includes the second cover plate 14, the housing assembly 1 may or may not include the first cover plate 13. Furthermore, when the housing assembly 1 includes both the second cover plate 14 and the first cover plate 13, the first cover plate 13 may be a composite of multiple materials or a non-composite of the same material.

[0352] In the above technical solution, at least a portion of the conductive portion 22 is located in the second receiving groove 12120, and the second cover plate 14 covers the conductive portion 22 of this portion. The second cover plate 14 also covers the first perforation 12130, so that when the electrolyte enters the second receiving groove 12120 from the first perforation 12130, the second cover plate 14 can improve the problem of overflow of this portion of the electrolyte from the first pole 12, thereby improving the reliability of the battery cell 10.

[0353] For example, as shown in Figures 27 and 28, when a portion of the conductive portion 22 is sandwiched between the second cover plate 14 and the second end wall 12121, laser welding can be used to weld the portion of the conductive portion 22, the second cover plate 14, and the second end wall 12121 together to improve the reliability of the connection between the first pole 12 and the conductive portion 22. Furthermore, because the second cover plate 14 can compress the conductive portion 22, the second cover plate 14 can be used to improve the stability of the conductive portion 22 within the second receiving groove 12120.

[0354] In conjunction with Figures 33-35, in some embodiments, the battery cell 10 also includes a bracket 3, which is located in the shell 11 and on the side of the active material coating portion 21 close to the first pole 12. The bracket 3 has an avoidance hole 31 for avoiding the conductive portion 22. The conductive portion 22 is suitable for extending to the side of the bracket 3 away from the active material coating portion 21 through the avoidance hole 31 to be welded to the first pole 12, thereby ensuring the normal charging and discharging operations of the battery cell 10.

[0355] In the above technical solution, a bracket 3 is provided on the side of the active material coating portion 21 close to the first pole 12, so that the bracket 3 can be used to separate the active material coating portion 21 from the shell 11, thereby improving the reliability of the battery cell 10, and an avoidance hole 31 is provided on the bracket 3, which can guide and constrain the conductive portion 22 to cooperate with the first pole 12 by passing through the avoidance hole 31, thereby eliminating the need for the conductive portion 22 to bypass the edge of the bracket 3 to approach the first pole 12, thereby simplifying the arrangement of the conductive portion 22, saving material of the conductive portion 22, and reducing costs, and also supporting and guiding the conductive portion 22 to cooperate with the first pole 12 by the bracket 3, which can reduce the risk of short-circuiting between the conductive portion 22 and the active material coating portion 21, thereby further improving the reliability of the battery cell 10.

[0356] In some embodiments, the pole body 1201 is provided with a first receiving portion 121 , and the bracket 3 is provided with a guide portion 32 . The guide portion 32 surrounds at least a portion of the avoidance hole 31 , and at least a portion of the guide portion 32 extends to the first receiving portion 121 .

[0357] It is worth noting that the guide portion 32 protrudes from the bracket 3 and extends into the first accommodating portion 121, and at least a portion of the avoidance hole 31 is formed in the guide portion 32, so that when the conductive portion 22 is passed through the avoidance hole 31, at least a portion of the conductive portion 22 can be easily received in the first accommodating portion 121, thereby improving the assembly efficiency of the conductive portion 22; at the same time, through the provision of the guide portion 32, the cooperation between the bracket 3 and the first pole 12, and between the bracket 3 and the conductive portion 22 are tighter and more reliable, making the structure of the battery cell 10 more compact, which is more conducive to the improvement of the energy density of the battery cell 10.

[0358] 33 to 35 , optionally, a third groove 38 is provided on the bracket 3 , and at least a portion of the first pole 12 located in the housing 11 is accommodated in the third groove 38 .

[0359] In the above technical solution, by providing a third groove 38 on the bracket 3, at least part of the portion of the first pole 12 located in the shell 11 is accommodated in the third groove 38 of the bracket 3, thereby improving the compactness of the structure. On the one hand, it is beneficial to reduce the space occupied by the bracket 3 in the shell 11, and on the other hand, it is also beneficial to improve the stability and reliability of the first pole 12, so as to ensure the reliability and stability of the electrical connection between the first pole 12 and the battery cell assembly 2, so as to improve the reliability and stability of the charging and discharging operations of the battery cell 10.

[0360] Furthermore, in some embodiments, the guide portion 32 can be used to help define the third groove 38, thereby simplifying the structure of the bracket 3, reducing the difficulty of designing and processing the bracket 3, and facilitating increasing the wall thickness of the guide portion 32, thereby improving the guiding reliability of the conductive portion 32. Furthermore, this also helps improve the stability and reliability of the first pole 12, thereby ensuring the reliability and stability of the electrical connection between the first pole 12 and the battery cell assembly 2, and thus improving the reliability and stability of the charging and discharging operations of the battery cell 10.

[0361] In conjunction with Figures 33-35, in some embodiments, the avoidance hole 31 includes a first hole segment 311 and a second hole segment 312. The second hole segment 312 is located on a side of the first hole segment 311 close to the active material coating portion 21, and the cross-sectional area of ​​the second hole segment 312 gradually increases in a direction away from the first hole segment 311. The active material coating portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211. The conductive portion 22 includes an electrode ear portion 221 electrically connected to the current collector 211. The pole ear portion 221 includes a plurality of pole ear sheets 2211, and the plurality of pole ear sheets 2211 converge at a position close to the current collector 211 to form a first gathered portion 2212, and the plurality of pole ear sheets 2211 converge at a position away from the current collector 211 and are connected to form a second gathered portion 2213, and the first gathered portion 2212 connects the second gathered portion 2213 and the active material coating portion 21, and at least a portion of the first gathered portion 2212 is accommodated in the second hole segment 312, and the second gathered portion 2213 is passed through the first hole segment 311.

[0362] In the above technical solution, by configuring the avoidance hole 31 to include a second hole segment 312 that gradually expands toward the active material coating portion 21, the second hole segment 312 can accommodate more first retracted portions 2212, thereby improving the compactness of the support 3 and the battery cell assembly 2. This reduces the overall volume of the battery cells 10, allowing the battery 100 to accommodate a larger number of battery cells 10, thereby increasing the volumetric energy density of the battery 100. Furthermore, in the above technical solution, the specific explanations of the first retracted portions 2212 and the second retracted portions 2213 have been described in the previous embodiments and will not be repeated here.

[0363] In some embodiments, the bracket 3 is an integrated structure; or, in conjunction with Figure 36, the bracket 3 is a split structure and includes a detachable first bracket 33 and a second bracket 34, and an avoidance hole 31 is defined between the first bracket 33 and the second bracket 34.

[0364] In the above technical solution, the avoidance hole 31 is formed as a through-hole extending through the bracket 3. As a result, the one-piece structure of the bracket 3 is easy to manufacture, improves reliability, and facilitates assembly of the bracket 3 with the housing assembly 1, thereby improving assembly efficiency and mating stability. It will be appreciated that the processing method of the bracket 3 can be selected based on the specific material of the bracket 3. For example, when the bracket 3 is an insulating plastic part, the one-piece structure of the bracket 3 can be obtained by injection molding.

[0365] Referring to Figure 37 , when the bracket 3 is a split structure, it includes a detachable first bracket 33 and a second bracket 34. Both the first bracket 33 and the second bracket 34 are elongated, plate-like structures that can be detachably connected, for example, by plugging or snapping them together for easy assembly. Furthermore, the first bracket 33 has a semi-hole structure on one side near the second bracket 34, and the second bracket 34 also has another semi-hole structure of a matching shape near the first bracket 33. Together, the semi-hole structures of the first bracket 33 and the second bracket 34 form an annular avoidance hole 31. That is, the avoidance hole 31 is defined between the first bracket 33 and the second bracket 34.

[0366] In the above technical solution, the avoidance hole 31 is defined by the cooperation of the first bracket 33 and the second bracket 34. When the bracket 3 is assembled with the battery cell assembly 2, there is no need to pass the conductive part 22 from one end of the avoidance hole 31 to the other end. Instead, the first bracket 33 and the second bracket 34 can be spliced ​​and clamped at the position of the conductive part 22 to make the avoidance hole 31 surround the conductive part 22, thereby facilitating the assembly of the bracket 3 and the battery cell assembly 2 and improving the assembly efficiency.

[0367] As an optional solution, when the cross-section of the avoidance hole 31 is long and strip-shaped, the first bracket 33 and the second bracket 34 are placed on both sides of the avoidance hole 31 in the width direction. For example, if the width direction of the avoidance hole 31 is the left and right direction, the first bracket 33 and the second bracket 34 are located on the left and right sides of the avoidance hole 31, thereby facilitating the cooperation between the first bracket 33, the second bracket 34 and the conductive part 22.

[0368] With reference to Figures 33, 38, and 39, in the embodiments of the present application, the configuration of the bracket 3 is not limited thereto. For example, the edge of the bracket 3 may further be provided with a shell entry guide surface 35. The shell entry guide surface 35 may be an inclined or curved surface, and when orthographically projected along the axial direction R of the first electrode 12, the orthographic projection of the active material coating portion 21 is entirely within the orthographic projection range of the bracket 3, and the orthographic projection range of the bracket 3 exceeds the orthographic projection range of the active material coating portion 21. During assembly, the bracket 3 and the cell assembly 2 can be pre-assembled together, and this pre-assembled assembly is then installed into the housing 11. During installation, the bracket 3 is positioned at the front end of the active material coating portion 21, that is, the bracket 3 enters the housing 11 before the active material coating portion 21. This reduces the difficulty of the bracket 3 entering the housing 11 by utilizing the shell entry guide surface 35. The relatively large projected area of ​​the bracket 3 also protects the active material coating portion 21, reducing the chance of scratching and damage between the active material coating portion 21 and the housing 11, thereby improving assembly efficiency and success rate. Moreover, the contact area between the bracket 3 and the active material coating portion 21 can be increased, which can reduce the stress concentration problem and eliminate other structural parts.

[0369] 38 , in some embodiments of the present application, the battery cell 10 may further include an inner insulating member 4, which is located inside the shell 11 and wrapped around the outside of the active material coating portion 21, and the inner insulating member 4 is connected to the bracket 3. In the above embodiment, on the one hand, by wrapping the inner insulating member 4 around the outside of the active material coating portion 21, the insulation reliability between the active material coating portion 21 and the shell 11 can be improved, and the corrosion of the shell 11 caused by the contact between the active material coating portion 21 and the shell 11 can be reduced or prevented, and the leakage of electrolyte caused by the corrosion of the shell 11 can be reduced, thereby improving the reliability of the battery cell 10; on the other hand, by connecting the inner insulating member 4 to the bracket 3, the difficulty of fixing the inner insulating member 4 can be reduced, and the reliability of the inner insulating member 4 wrapped around the outside of the active material coating portion 21 can be improved.

[0370] With reference to FIG38 , in an embodiment of the present application, the bracket 3 includes a main body 36 and an extension 37 . The main body 36 is located on the side of the active material coating portion 21 close to the first pole 12 . The extension 37 is connected to the main body 36 and is located in the peripheral area of ​​the active material coating portion 21 . For example, the extension 37 can be connected to the circumferential edge of the main body 36 to form an annular extension structure connected to the main body 36 , or it can be a partial extension of the circumference of the main body 36 to form a block-shaped structure protruding relative to the main body 36 . On the one hand, the provision of the extension 37 can limit the active material coating portion 21 to improve the problem of carbon powder falling off the edge of the active material coating portion 21 and overlapping with the shell 11 to cause corrosion. On the other hand, the provision of the extension 37 can also fix the internal insulator 4, improve the connection reliability between the internal insulator 4 and the bracket 3 , and have a better insulation effect.

[0371] Exemplarily, in combination with Figure 38, the main body 36 and the extension portion 37 can define a positioning groove 39 located on the side of the extension portion 37 away from the active material coating portion 21, and the end of the inner insulating part 4 is embedded in the positioning groove 39 to prevent the inner insulating part 4 from protruding from the edge of the main body 36. In this way, when entering the shell, the main body 36 can be used to protect the inner insulating part 4, reducing the chance of damage to the inner insulating part 4 and the shell 11 due to scratches.

[0372] Specifically, in conjunction with Figure 39, the internal insulating part 4 can be an integrated film, having a main body 41 located on both sides of the active material coating part 21 in the thickness direction and a connecting part 42 connecting the two main body parts 41, the connecting part 42 is located on the side of the active material coating part 21 away from the first pole 12, and the edge of the side of the main body 41 away from the connecting part 42 extends to the extension part 37 and is connected to the extension part 37, so that it has better insulation performance and is easy to connect.

[0373] In the embodiment of the present application, the specific manner of setting the first pole 12 on the housing 11 is not limited, and may be, for example, riveting or welding, etc., which are described below respectively.

[0374] In some embodiments, in combination with Figures 56 and 57, the shell 11 has a first wall 110, and the first wall 110 is formed with a mounting hole 113. The pole body 1201 is arranged in the mounting hole 113. The surface where the cross section of the mounting hole 113 is located is the projection surface. Along the direction perpendicular to the projection surface, the ratio of the projection area of ​​the first welding portion 71 on the projection surface to the projection area of ​​the first wall 110 on the projection surface is in the range of 0.1% to 1%.

[0375] The cross-section of the mounting hole 113 is perpendicular to the axial direction (third direction Z) of the mounting hole 113, and the projection direction in the above conditions is parallel to the axial direction of the mounting hole 113. The orthographic projection area of ​​the first welding portion 71 can be understood as the orthographic projection area of ​​the connection area between the conductive portion 22 and the pole body 1201 on the cross-section of the mounting hole 113. Then the orthographic projection area of ​​the first welding portion 71 on the cross-section of the mounting hole 113 can reflect the area size of the connection area between the conductive portion 22 and the pole body 1201. If the orthographic projection area of ​​the first welding portion 71 on the cross-section of the mounting hole 113 meets the above conditions, the equivalent resistance between the conductive portion 22 and the pole body 1201 can be reduced to a certain extent, the flow area of ​​the first pole 12 can be increased, and the flow capacity of the first pole 12 can be increased, which is beneficial to improving the charging speed of the battery cell 10 and improving the fast charging performance of the battery cell 10. At the same time, it is also beneficial to improving the thermal diffusion capacity of the first pole 12 to a certain extent.

[0376] In the above technical solution, by setting the ratio of the projected area of ​​the first welding portion 71 on the projection surface to the projected area of ​​the first wall 110 on the projection surface within the range of 0.1% to 1%, the effective flow area between the conductive portion 22 and the pole body 1201 is increased, the flow area of ​​the first pole 12 is increased, and the flow capacity of the first pole 12 is increased, which is beneficial to improving the charging speed of the battery cell 10. At the same time, it is also beneficial to improve the thermal diffusion capacity of the first pole 12 to a certain extent, reduce the overcurrent temperature of the first pole 12, and help reduce the risk of loss of control of the battery cell 10.

[0377] In some embodiments, in combination with Figure 57, the shell 11 has a mounting hole 113, and the pole body 1201 includes an integrally formed pole body portion 12a, a first limit platform portion 12b and a second limit platform portion 12c. The pole body portion 12a is passed through the mounting hole 113 of the shell 11, and the first limit platform portion 12b and the second limit platform portion 12c are arranged at both ends of the pole body portion 12a along the axial direction of the mounting hole 113. The first limit platform portion 12b is limited and matched with the outer side of the shell 11, and the second limit platform portion 12c is limited and matched with the inner side of the shell 11, so that the pole body 1201 is riveted to the shell 11.

[0378] It can be seen that the first limiting platform 12b and the second limiting platform 12c extend radially along the mounting hole 113 to the radially outer side of the peripheral wall of the mounting hole 113 respectively. The first limiting platform 12b can limit the movement of the first pole 12 relative to the shell 11 in the direction toward the inner side of the shell 11, while the second limiting platform 12c can limit the movement of the first pole 12 relative to the shell 11 in the direction toward the outer side of the shell 11, so that the first pole 12 can be easily and reliably installed in the mounting hole 113 through the first limiting platform 12b and the second limiting platform 12c, thereby realizing the fixed connection between the first pole 12 and the shell 11, facilitating the assembly of the first pole 12 and the shell 11, and there is no need to adopt other connection methods between the first pole 12 and the shell 11, that is, it is easy to realize the reliable connection between the first pole 12 and the shell 11, which is conducive to simplifying the structure of the shell assembly 1 and simplifying the assembly process of the shell assembly 1.

[0379] Moreover, since the pole main body 12a, the first limit platform 12b and the second limit platform 12c are formed as one piece, it is possible to save parts and reduce costs. At the same time, it is convenient to ensure the strength of the first pole 12, so that after the first pole 12 is matched with the shell 11, it is not easy for the first pole 12 to separate from the shell 11 due to vibration or external pulling during the charging and discharging process of the battery cell 10, nor is it easy to crack or be damaged due to vibration or external pulling, which can improve the stability and reliability of the shell assembly 1, thereby improving the stability and reliability of the battery cell 10.

[0380] Exemplarily, the axial direction of the mounting hole 113 is the third direction Z, the side wall of the shell 11 in the third direction Z is formed with a through mounting hole 113, and the first limit platform portion 12b and the second limit platform portion 12c are arranged at both ends of the pole body portion 12a along the third direction Z.

[0381] It should be noted that in the above technical solution, the pole of the shell assembly 1 can be one or more, wherein at least one pole is a first pole 12 including an integrally formed pole body 12a, a first limit platform 12b and a second pole body 12a, a first limit platform 12b and a second limit platform 12c, or a part of the poles on the shell 11 are the first pole 12 including an integrally formed pole body 12a, a first limit platform 12b and a second limit platform 12c, and the other part of the poles are other structures.

[0382] It is understandable that, in the present application, the first pole 12 can be used as a positive pole or a negative pole, and there is no limitation here.

[0383] For example, refer to Figure 57, which is a schematic diagram of the assembly process of the first pole 12 and the first wall 110 provided in some embodiments of the present application. The first limit platform 12b, the second limit platform 12c and the pole body 12a are an integrated part. Before the first pole 12 is riveted to the shell 11, one of the first limit platform 12b and the second limit platform 12c can extend along the axial direction of the mounting hole 113, and the other can extend along the radial direction of the mounting hole 113. After the pole body 12a is passed through the mounting hole 113, tools can be used to rivet one of the above-mentioned piers of the first limit platform 12b and the second limit platform 12c to extend along the radial direction of the mounting hole 113 to achieve riveting fixation of the first pole 12 to the shell 11.

[0384] In some embodiments, as shown in Figures 60, 61 and 65, in the axial direction, the thickness of the first limit platform portion 12b is t1, 2mm≤t1≤3.2mm, so as to take into account the riveting strength of the first pole 12 at the first limit platform portion 12b and the volume energy density of the battery cell 10 at the same time, to avoid setting the thickness of the first limit platform portion 12b to be larger due to consideration of the riveting strength of the first pole 12, thereby reducing the volume energy density of the battery cell 10, and at the same time to avoid setting the thickness of the first limit platform portion 12b to be smaller due to consideration of the volume energy density of the battery cell 10, thereby causing the riveting strength of the first pole 12 at the first limit platform portion 12b to be poor.

[0385] For example, t1 may be 2 mm, 2.2 mm, 2.5 mm, 2.7 mm, 2.9 mm, 3 mm, or 3.2 mm.

[0386] In some embodiments, as shown in Figures 60, 61, and 62, the width of the first limiting platform 12b in the radial direction of the mounting hole 113 is x1, where x1 ≥ 1 mm, so as to enhance the limiting effect of the first limiting platform 12b on the first terminal 12, thereby to a certain extent improving the reliability of the riveting between the first terminal 12 and the housing 11. The width d of the first limiting platform 12b can be understood as the distance from the outer peripheral wall of the terminal body 12a to the outer side wall of the first limiting platform 12b along the radial direction of the mounting hole 113.

[0387] For example, x1 may be 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm, etc.

[0388] In some embodiments, as shown in Figures 60, 61 and 62, in the axial direction, the thickness of the second limit platform portion 12c is t2, t2≤2mm, so as to take into account the riveting strength of the first pole 12 at the second limit platform portion 12c and the volume energy density of the battery cell 10 at the same time, to avoid setting the thickness of the second limit platform portion 12c to be larger due to consideration of the riveting strength of the first pole 12, thereby reducing the volume energy density of the battery cell 10, and at the same time to avoid setting the thickness of the second limit platform portion 12c to be smaller due to consideration of the volume energy density of the battery cell 10, thereby causing the riveting strength of the first pole 12 at the second limit platform portion 12c to be poor.

[0389] For example, t2 may be 2 mm, 1.8 mm, 1.5 mm, 1.4 mm, or 1.2 mm, etc.

[0390] In some embodiments, the distance between the end of the second limiting platform 12c away from the first limiting platform 12b and the inner wall of the shell 11 in the axial direction of the mounting hole 113 is less than or equal to 2 mm, so as to further improve the energy density of the battery cell 10.

[0391] In some embodiments, at least one of the first limiting platform 12b and the second limiting platform 12c is a separate part from the pole body 12a and is fixedly connected. That is to say, the first limiting platform 12b or the second limiting platform 12c can be a separate part from the pole body 12a and is fixedly connected, or the first limiting platform 12b and the second limiting platform 12c are both a separate part from the pole body 12a and are fixedly connected. In this technical solution, since at least one of the first limiting platform 12b and the second limiting platform 12c is a separate part from the pole body 12a, it is relatively easy to operate when assembling the first pole 12 with the shell 11, which can reduce the difficulty of assembly, and is conducive to later disassembly and replacement, thereby reducing the cost of use.

[0392] In some embodiments, at least one of the first limiting platform portion 12b and the second limiting platform portion 12c is welded to the pole body portion 12a.

[0393] In some embodiments, the pole body 12a, the first limit platform 12b and the second limit platform 12c are an integral part. It can be understood that this method can reduce the assembly steps between the first pole 12 and the shell 11, simplify the assembly process, and improve work efficiency. At the same time, setting the pole body 12a, the first limit platform 12b and the second limit platform 12c as an integral part can also make the installation between the first pole 12 and the shell 11 more reliable, and can reduce the risk of the split pole falling off between the first pole 12 and the shell 11 due to loose components.

[0394] Secondly, the materials of the pole body 12a, the first limiting platform 12b and the second limiting platform 12c can be the same or different; of course, the pole body 12a, the first limiting platform 12b and the second limiting platform 12c can also be separate parts.

[0395] In some embodiments, as shown in Figures 60, 61 and 62, the battery 100 further includes an insulating sealing component 8, which is disposed between the first pole 12 and the shell 11 to achieve insulation and sealing between the first pole 12 and the shell 11.

[0396] In some embodiments, as shown in Figures 60, 61 and 62, the insulating sealing component 8 includes an insulating member 81 and a sealing member 82. The insulating member 81 is arranged between the first limit platform 12b and the shell 11; the sealing member 82 is arranged between the second limit platform 12c and the shell 11. A portion of the insulating member 81 and / or a portion of the sealing member are fitted between the pole body 12a and the peripheral wall of the mounting hole 113. The insulating member 81 can play an insulating role between the first limit platform 12b and the shell 11 to ensure insulation reliability, while the sealing member 82 can play a sealing role so that the electrolyte in the shell 11 is not easy to overflow.

[0397] In some embodiments, as shown in Figures 60, 61, and 62, the outer wall of the housing 11 is formed with a mating groove to accommodate the insulating member 81, which facilitates the positioning and installation of the insulating member 8. To a certain extent, this can prevent the insulating member 8 from being easily misaligned during the riveting process between the first terminal 12 and the housing 11. At the same time, under the premise of reliable use of the housing 11, the provision of the mating groove is conducive to reducing the height of the insulating member 8 protruding from the outer wall of the housing 11, which is conducive to reducing the height of the first terminal 12 protruding from the outer wall of the housing 11, thereby improving the volume energy density (VED) of the battery cell 10. Of course, the outer wall of the housing 11 can also be formed with no mating groove.

[0398] In some embodiments, as shown in Figures 60, 61, and 62, the inner sidewall of the housing 11 is formed with a mating protrusion that abuts against the seal 82 to improve the sealing reliability of the seal 82. Of course, the inner sidewall of the housing 11 may also not be formed with the mating protrusion.

[0399] For example, in the examples shown in Figures 60, 61 and 62, the outer wall of the shell 11 is formed with a mating groove to accommodate the insulating member 8, and the inner wall of the shell 11 is formed with a mating protrusion, which stops at the sealing member 82.

[0400] Optionally, the insulating sealing component 8 can be an integral part, that is, the insulating part 8 and the sealing part 82 are an integral part, in which case the materials of the insulating part 8 and the sealing part 82 can be the same or different; of course, the insulating part 8 and the sealing part 82 can also be separate parts.

[0401] Specifically, with reference to Figures 40-42, the first pole 12, before being riveted, may include a stopper 1281 and a penetration portion 1282. During assembly, the stopper 1281 is stopped inside the housing 11, and the penetration portion 1282 is penetrated through the mounting hole 113. The portion of the penetration portion 1282 located outside the housing 11 is then riveted to form a flange 1283. The flange 1283 is stopped outside the housing 11, thereby achieving installation of the first pole 12. It should be noted that the penetration portion 1282 may refer to the pole body 12a hereinafter, the stopper 1281 may refer to the second limiting platform 12c hereinafter, and the flange 1283 may refer to the first limiting platform 12b hereinafter.

[0402] Optionally, referring to Figures 40 and 41 , the housing assembly 1 may include several sealing gaskets, such as the first sealing gasket 191 and the second sealing gasket 192 shown in Figure 40 , that fit between the housing 11 and the first pole 12. The sealing gaskets are assembled in place before riveting. After the first pole 12 is riveted, the first pole 12 presses against the sealing gaskets to form a seal, thereby improving the sealing performance at the joint between the first pole 12 and the housing 11. The number, position, and material of the sealing gaskets are not limited, and the materials may be, for example, silicone, plastic, etc., and are not limited here.

[0403] Optionally, referring to FIG41 , the length c of the flange portion 1283 may be greater than or equal to 1 mm, and the thickness d may be greater than or equal to 2 mm, to improve the riveting strength of the first pole 12. When the length c of the flange portion 1283 is less than 1 mm and / or the thickness d is less than 2 mm, the reliability of the first pole 12 and the housing 11 may be reduced under relatively strong vibration.

[0404] For another example, in other embodiments of the present application, with reference to FIG6 and FIG7 , the first pole 12 may be a split structure that is welded together for installation on the housing 11. For example, the first pole 12 includes a first portion 1291 and a second portion 1292, wherein at least a portion of the first portion 1291 is abutted against the exterior of the housing 11, and at least a portion of the second portion 1292 is abutted against the interior of the housing 11. The first pole 12 may be installed by inserting at least one of the first portion 1291 and the second portion 1292 into the mounting hole 113 and welding the other portion (e.g., laser welding).

[0405] In some optional embodiments, referring to FIG. 45 and FIG. 46 , there are multiple first poles 12 and all of them are located on the same side surface of the housing 11 , thereby facilitating installation and improving assembly efficiency.

[0406] It should be noted that the arrangement of the multiple first poles 12 on the same side surface is not limited. For example, when the cross-section of the first pole 12 is an elongated structure, for example, a cross-sectional length greater than or equal to three times the cross-sectional width, such as an elliptical, racetrack, or rectangular shape, it has better adaptability to the thin and flat shape of the housing 11. For example, the multiple first poles 12 are all provided on a side surface of the housing 11 in the height direction (denoted as the first wall 110), the length direction of each first pole 12 is consistent with the length direction of the first wall 110 of the housing 11, and the multiple first poles 12 are spaced apart along the length direction and / or width direction of the first wall 110.

[0407] For example, in the example shown in FIG45 , when the first wall 110 has two first poles 12, the two first poles 12 are spaced apart along the length of the first wall 110. Optionally, in conjunction with FIG45 , the portion of the first pole 12 located outside the housing 11 (denoted as the pole outer portion) is annular. Along the length of the first wall 110, the inner ring length a1 of the pole outer portion is greater than or equal to 1 / 3 of the length a0 of the first wall 110, and along the width of the first wall 110, the inner ring width b1 of the pole outer portion is greater than or equal to 3 / 4 of the width b0 of the first wall 110. This facilitates providing a larger area for the first pole 12 to electrically connect to the current-carrying component, thereby further improving the current carrying capacity of the first pole 12. For example, the inner ring length a1 of the pole outer portion is greater than or equal to 50 mm, and the inner ring width b1 of the pole outer portion is greater than or equal to 30 mm.

[0408] In addition, with reference to FIG45 , when the first wall 110 has two first poles 12, and the two first poles 12 are spaced apart along the length direction of the first wall 110, in some optional embodiments, the first pole 12 includes a portion located within the housing 11 (denoted as the pole interior). In the length direction of the first wall 110, the length of the pole interior is greater than or equal to 1 / 3 of the length of the first wall 110, and in the width direction of the first wall 110, the width of the pole interior is greater than or equal to 3 / 4 of the width of the first wall 110. This facilitates providing a larger area for the first pole 12 to electrically connect with the conductive portion 22, thereby further improving the current carrying capacity of the first pole 12. For example, the length of the pole interior is greater than or equal to 50 mm, and the width of the pole interior is greater than or equal to 30 mm.

[0409] For example, in the example shown in FIG46 , when the first wall 110 has four first poles 12, two of the first poles 12 are spaced apart along the width of the first wall 110 to form a group, for a total of two groups spaced apart along the length of the first wall 110. Optionally, referring to FIG46 , the portion of the first pole 12 located outside the housing 11 (denoted as the pole outer portion) is annular. Along the length of the first wall 110, the inner ring length a2 of the pole outer portion is greater than or equal to 1 / 3 of the length a0 of the first wall 110, and along the width of the first wall 110, the inner ring width b2 of the pole outer portion is greater than or equal to 1 / 5 of the width b0 of the first wall 110. This facilitates providing a larger area for the first pole 12 to electrically connect to the busbar, thereby further improving the current carrying capacity of the first pole 12. For example, the inner ring length a2 of the pole outer portion is greater than or equal to 50 mm, and the inner ring width b2 of the pole outer portion is greater than or equal to 8 mm.

[0410] In addition, with reference to FIG46 , when the first wall 110 has four first poles 12, with two first poles 12 spaced apart along the width direction of the first wall 110 to form a group, with a total of two groups spaced apart along the length direction of the first wall 110, in some optional embodiments, the first pole 12 includes a portion located within the housing 11 (denoted as the pole interior). In the length direction of the first wall 110, the length of the pole interior is greater than or equal to 1 / 3 of the length of the first wall 110, and in the width direction of the first wall 110, the width of the pole interior is greater than or equal to 1 / 5 of the width of the first wall 110. This facilitates providing a larger area for the first pole 12 to electrically connect with the conductive portion 22, thereby further improving the current carrying capacity of the first pole 12. For example, the length of the pole interior is greater than or equal to 50 mm, and the width of the pole interior is greater than or equal to 8 mm.

[0411] In some embodiments, referring to FIG45 and FIG46 , a portion of the first pole 12 is located inside the housing 11, and a portion of the first pole 12 is located outside the housing 11. The orthographic projection area of ​​the portion of the first pole 12 located outside the housing 11 on the first wall 110 is greater than or equal to 5% of the area of ​​the first wall 110. For example, the orthographic projection area of ​​the portion of the first pole 12 located outside the housing 11 on the first wall 110 is greater than or equal to 5%, 6%, 7%, 8%, 9%, 10%, etc. of the area of ​​the first wall 110. This helps increase the connection area between the first pole 12 and the current busbar, increases the effective flow area between the first pole 12 and the current busbar, and helps increase the charging speed of the battery cell 10.

[0412] In addition, in some embodiments, combined with Figure 47, the vertical height t1 of the portion of the first pole 12 protruding from the outer surface of the first wall 110 (recorded as the pole outside) from the first wall 110 can be less than or equal to 3.2 mm, and the vertical height t2 of the portion of the first pole 12 protruding from the inner surface of the first wall 110 (recorded as the pole inside) from the first wall 110 can be less than or equal to 2 mm, so as to improve the volume energy density of the battery cell 10.

[0413] Figure 48 is a schematic cross-sectional view of a housing assembly 1 according to some embodiments of the present application; Figure 49 is a schematic cross-sectional view of a housing assembly 1 according to some embodiments of the present application; Figure 50 is an orthographic view of a battery cell 10 according to some embodiments of the present application; Figure 51 is a cross-sectional view taken along line EE in Figure 50; and Figure 52 is a schematic partial cross-sectional view of a battery cell 10 according to some embodiments of the present application. Referring to Figures 48 to 52, in the embodiments of the present application, the housing 11 specifically includes a housing body 111 and a housing cover 112. The housing body 111 is a square ring-shaped structure with one or both ends open. When one end is open, there is one housing cover 112, which is positioned in the open position. When both ends are open, there are two housing covers 112, one covering each of the open ends of the housing body 111.

[0414] In detail, when the housing 11 includes a body 111 and a cover 112, and one end of the body 111 is open, the body 111 is an integrally formed part, specifically a square structure formed by stretching. In this case, the first pole 12 can be provided on at least one of the body 111 or the cover 112. For example, in conjunction with FIG48, the first pole 12 can be provided at the end of the body 111 away from the cover 112. When the battery cell 10 is used in a vibrating environment, the amplitude of the connection between the body 111 and the cover 112 is small, and the connection between the body 111 and the cover 112 is not easy to crack, which can improve the reliability of the battery cell 10 and can help reduce the wall thickness of the body 111, thereby reducing cost and weight, and helping to achieve miniaturization of the battery cell 10.

[0415] As an optional solution, referring again to Figure 48 , when there are multiple first terminals 12, all first terminals 12 are located at the end of the housing 111 away from the housing cover 112. Thus, when the battery cell 10 is used in a vibrating environment, the amplitude of vibration at the connection between the housing 111 and the housing cover 112 is small, and the connection between the housing 111 and the housing cover 112 is less likely to crack, thereby improving the reliability of the battery cell 10. Furthermore, the wall thickness e1 of the end wall of the housing 111 away from the housing cover 112 can be reduced to less than or equal to 2 mm, and the wall thickness e2 of the side wall of the housing 111 connecting the end wall to the housing cover 112 can be reduced to less than or equal to 0.8 mm. This can reduce cost and weight, and facilitate miniaturization of the battery cell 10.

[0416] When the first receiving groove 12110 corresponding to the mounting hole 113 is provided on the first pole 12, the wall thickness of the portion of the first pole 12 located on the side of the first receiving groove 12110 away from the active material coating portion 21 is thinner, so that the welding of the conductive portion 22 and the first pole 12 can be achieved from the outside of the shell 11. As shown in Figure 48, for the case where the shell 11 includes a shell body 111 and a shell cover 112, and the shell cover 112 is arranged at the open end of the shell body 111, even if the first pole 12 is arranged at the closed end of the shell body 111, there is no need to worry about the difficulty in welding the conductive portion 22 and the first pole 12 from the inside of the shell 11, because the conductive portion 22 and the first pole 12 can be welded from the outside of the shell 11, so that the connection stability and reliability of the shell body 111 and the shell cover 112 can be improved by arranging the first pole 12 at the closed end of the shell body 111.

[0417] When the above-mentioned second accommodating groove 12120 is opened on the first pole 12, since the welding of the conductive part 22 and the first pole 12 can be achieved from the outside of the shell 11 through the notch of the second accommodating groove 12120, combined with Figure 48, for the shell 11 including the shell body 111 and the shell cover 112, the shell cover 112 is arranged at the open end of the shell body 111, even if the first pole 12 is arranged at the closed end of the shell body 111, there is no need to worry about the difficulty in welding the conductive part 22 and the first pole 12 from the inside of the shell 11, because the conductive part 22 and the first pole 12 can be welded from the outside of the shell 11, so that the connection stability and reliability of the shell body 111 and the shell cover 112 can be improved by arranging the first pole 12 at the closed end of the shell body 111.

[0418] 49 , in other embodiments of the present application, all first poles 12 may be provided on the housing cover 112 as required. This facilitates assembly of the first poles 12 and the housing cover 112, which is not limited in this embodiment.

[0419] 50-52 , in the embodiment of the present application, when there are multiple first poles 12, the first poles 12 may also be disposed on two surfaces on different sides of the housing 11. For example, there are multiple first poles 12 disposed on two adjacent surfaces of the housing 11, or there are multiple first poles 12 disposed on two opposite surfaces of the housing 11.

[0420] When first poles 12 are provided on opposite sides of the housing 11, conductive portions 22 can extend from the active material coating portion 21 near the first pole 12 on each side. The conductive portions 22 cooperate with and connect to the first pole 12 on the adjacent side, thereby improving the problem of the pole ear 221 being pulled by the first pole 12 on the same side, which could cause cracking in the connection between the pole ear 221 and the active material coating portion 21, thereby improving the reliability of the battery cell 10. It is worth noting that the first poles 12 on both sides can be the same or different, and the connection method between the first poles 12 on both sides and the conductive portion 22 can be the same or different, without limitation herein.

[0421] Of course, in other embodiments of the present application, the first pole 12 can also be arranged on the side surface with the largest area of ​​the shell 11. For another example, in some optional embodiments of the present application, the first pole 12 can be located on the top surface of the shell 11. For another example, in some optional embodiments of the present application, the first pole 12 can be located on the bottom surface of the shell 11, and so on. Among them, when the first pole 12 is located on the bottom surface of the shell 11, the accommodating portion 121 can be used to accommodate the electrolyte, thereby improving the cycle life of the battery cell 10. In addition, when the first pole 12 is located on the bottom surface of the shell 11 and the bracket 3 is located at the bottom of the active material coating portion 21, the contact area between the bracket 3 and the active material coating portion 21 can be increased, thereby reducing the stress concentration problem and eliminating other supporting structural parts.

[0422] 43 , in some embodiments of the present application, the housing 11 has a pressure relief portion 16. The specific configuration of the pressure relief portion 16 is not limited, and it can be, for example, an explosion-proof valve or a weakened portion, etc., and can be used to relieve pressure when the pressure inside the battery cell 10 is high, thereby improving the reliability of the battery cell 10.

[0423] Optionally, the pressure relief portion 16 and the first pole 12 can be located on the same side of the housing 11. This facilitates processing and assembly. Alternatively, the pressure relief portion 16 and the first pole 12 can be located on opposite sides of the housing 11. This saves space, increases the volume of the first pole 12, and reduces the adverse effects of the pressure relief portion 16 on the first pole 12 when releasing pressure.

[0424] Please refer to Figures 48 and 53 again. In the embodiment of the present application, the pressure relief portion 16 can also be provided on the shell cover 112 as needed. Since the shell cover 112 does not need to bear the function of installing the first pole 12, and the connection position between the shell cover 112 and the shell body 11 is less affected by vibration during the charging and discharging process of the battery cell 10 and is not easy to crack, the thickness of the shell cover 112 is set to be relatively thin, which makes it easier to process and manufacture the pressure relief portion 16. For example, it is convenient to directly form the pressure relief portion 16 on the shell cover 112 by an integrated notch, so as to fully improve the manufacturability of the battery cell 10. It is worth noting that in this embodiment, the first pole 12 can be provided on the shell body 111 or the shell cover 112, and there is no limitation here. For example, the pressure relief portion 16 can be integrally formed with the shell cover 112, thereby facilitating processing, simplifying assembly, improving production efficiency, and reducing costs.

[0425] Please refer to FIG. 3-FIG . 5 , FIG. 18 , and FIG. 23 - FIG. 24 again for a description of the battery cell 10 according to a specific embodiment of the present application.

[0426] 3-5 , the battery cell 10 is a rectangular parallelepiped, with the height of the battery cell 10 being in a first direction Z, the length of the battery cell 10 being in a second direction X, and the thickness of the battery cell 10 being in a third direction Y. The battery cell 10 includes a housing 11, which comprises a body 111 and a cover 112. The body 111 is a square ring-shaped structure, with one end of the body 111 being open along the first direction Z and the other end being closed along the first direction Z. The cover 112 is disposed over the open portion of the body 111.

[0427] 3-5 , the closed end of the housing 111 along the first direction Z is provided with two poles, and the two poles are spaced apart along the second direction X to be a positive pole and a negative pole respectively. Both poles are first poles 12 provided with an accommodating portion 121, and the accommodating portion 121 includes a second accommodating groove 12120. Specifically, the first pole 12 includes a second end wall 12121 and a second side wall 12123. The second end wall 12121 is located on the side of the second side wall 12123 close to the shell cover 112. The second end wall 12121 and the second side wall 12123 are arranged to form the second accommodating groove 12120. The surface of the first pole 12 away from the shell cover 112 is the pole outer end surface 123. The notch of the second accommodating groove 12120 is formed on the pole outer end surface 123. A first through-hole 12130 is opened on the second end wall 12121. The first through-hole 12130 is located at a position of the second end wall 12121 close to the second side wall 12123.

[0428] 5 and 18 , the battery cell 10 further includes a cell assembly 2 , which includes an active material coating portion 21 and a pole ear portion 221 . The active material coating portion 21 is accommodated in the shell 11 , and the pole ear portion 221 extends through the first through-hole 12130 into the second accommodating groove 12120 and is welded to the second end wall 12121 to electrically connect the active material coating portion 21 and the first pole 12 through the pole ear portion 221 .

[0429] Referring to Figures 18, 23, and 24, a first cover plate 13 is embedded in the notch of the second receiving slot 12120. After the electrode lug 221 is welded to the second end wall 12121, the first cover plate 13 cooperates with the first terminal 12 to seal the notch of the second receiving slot 12120. The first cover plate 13 is welded to the first terminal 12 to form an electrical connection. Subsequently, when a busbar assembly is used to electrically connect battery cells 10, the busbar assembly can be welded to the first cover plate 13 to achieve an electrical connection with the first terminal 12.

[0430] In the above technical solution, on the one hand, the first electrode 12 is provided with a second receiving groove 12120, which can reduce the weight of the first electrode 12 to a certain extent, so as to improve the weight energy density of the battery cell 10 and the battery 100; on the other hand, since the notch of the second receiving groove 12120 is formed on the electrode outer end surface 123, and the electrode outer end surface 123 is the surface of the first electrode 12 away from the active material coating portion 21, the second receiving groove 12120 can be open in the direction away from the active material coating portion 21. In this way, when at least a portion of the electrode ear 221 is accommodated in the second receiving groove 12120, the electrode ear 221 can be easily stored and sorted through the notch of the second receiving groove 12120, and the electrode ear 221 and the first electrode 12 can be easily welded through the notch of the second receiving groove 12120, thereby reducing the production difficulty of the battery cell 10 and improving the production efficiency of the battery cell 10.

[0431] Furthermore, since the welding of the pole ear portion 221 and the first pole 12 can be achieved from the outside of the shell 11, the first pole 12 can be arranged on the closed end of the shell body 111. In this way, when the battery cell 10 is used in a vibration environment, the amplitude of the connection between the shell body 111 and the shell cover 112 is small, and the connection position between the shell body 111 and the shell cover 112 is not easy to crack, which can improve the reliability of the battery cell 10 and can help reduce the wall thickness of the shell body 111, thereby reducing cost and weight, and helping to achieve miniaturization of the battery cell 10.

[0432] At the same time, since the second receiving tank 12120 can be connected to the interior of the shell 11 through the first perforation 12130, the second receiving tank 12120 can also serve as a buffer and temporary storage structure for the electrolyte, so that more electrolyte can be accommodated in the shell 11. Since the battery cell 10 will lose electrolyte during the charging and discharging process, when there is more electrolyte, the service life of the battery cell 10 can be extended; and because the second receiving tank 12120 can be connected to the interior of the shell 11 through the first perforation 12130, the second receiving tank 12120 can also serve as a receiving and buffer structure for gas production inside the battery cell assembly 2, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0433] In some embodiments, as shown in Figures 74 and 75 , the battery cell 10 further includes an external insulating member 5 , which is wrapped around the exterior of the housing 11. In this embodiment, the external insulating member 5 serves as an insulator, isolating the housing 11 from external components. For example, the external insulating member 5 is a blue film.

[0434] In some embodiments, in combination with Figure 74, the shell 111 has a first wall 110, the first wall 110 is formed with a mounting hole 113, the pole body 1201 is arranged in the mounting hole 113, the battery cell 10 also includes a patch 9 covering the outside of the first wall 110, the external insulating part 5 includes an external insulating film 52, the external insulating film 52 is an integrated diaphragm, the external insulating film 52 has a connecting portion 51, the connecting portion 51 extends to the outside of the first wall 110 and is connected to the patch 9.

[0435] In the above technical solution, the connecting portion 51 can overlap with the patch 9 along the axial direction of the mounting hole 113, facilitating the connection between the connecting portion 51 and the patch 9. In this case, the outer insulating film 52 and the patch 9 can at least separate the first pole 12 on the first wall 110 from the housing 11, improving the insulation reliability between the first pole 12 and the housing 11, thereby improving the reliability of the battery cell 10. For example, in the examples of Figures 74 and 75, the connecting portion 51 can extend in an annular shape around the outer periphery of the first wall 110, so that the outer insulating member 5 is wrapped around all walls of the housing 11 except the first wall 110. The connecting portion 51 is provided between the patch 9 and the first wall 110, so that the patch 9 can play a certain protective role in the connection between the connecting portion 51 and the patch 9.

[0436] Optionally, the outer insulating member 5 is bonded to the housing 11 , and the patch 6 is bonded to the first wall 11 a .

[0437] In some embodiments, the first pole 12 is a solid structure, and the second welding portion 72 is formed on the portion of the first pole 12 located outside the shell 11. In this manner, the structure of the first pole 12 is simple and easy to process.

[0438] In some embodiments, the minimum distance between the edge of the outer insulating film 52 and the first pole 12 is greater than or equal to 3 mm. This allows for a creepage distance between the first pole 12 and the housing 11 to be greater than or equal to 3 mm, which helps improve the insulation withstand voltage performance between the first pole 12 and the housing 11. For example, the minimum distance t between the connecting portion 51 and the pole 12 can be 3 mm, 4 mm, 4.7 mm, 5 mm, or 5.2 mm.

[0439] In some embodiments, as shown in Figures 56-60 and 66, with the surface where the cross section of the mounting hole 113 is located as the projection surface, along the direction perpendicular to the projection surface, the projection area of ​​the first welding portion 71 on the projection surface is greater than or equal to 0.1% of the projection area of ​​the first wall 110 on the projection surface.

[0440] In the above technical solution, the cross-section of the mounting hole 113 is perpendicular to the axial direction of the mounting hole 113, and the projection direction in the above conditions is parallel to the axial direction of the mounting hole 113. The projection area of ​​the first welding portion 71 on the projection surface can be understood as the projection area of ​​the connection area between the conductive portion 22 and the pole body 1201 on the projection surface. Then the projection area of ​​the first welding portion 71 on the projection surface can reflect the area size of the connection area between the conductive portion 22 and the pole body 1201. If the projection area of ​​the first welding portion 71 on the projection surface meets the above conditions, the equivalent resistance between the conductive portion 22 and the pole body 1201 can be reduced to a certain extent, the flow area of ​​the first pole 12 can be increased, and the flow capacity of the first pole 12 can be increased, which is beneficial to improving the charging speed of the battery cell 10 and improving the fast charging performance of the battery cell 10. At the same time, it is also beneficial to improving the thermal diffusion capacity of the pole 12 to a certain extent.

[0441] In the above technical solution, by setting the projected area of ​​the first welding portion 71 between the conductive portion 22 and the pole body 1201 on the projected surface to be greater than or equal to 0.1% of the projected area of ​​the first wall 110 on the projected surface, the effective flow area between the conductive portion 22 and the pole body 1201 is greater than or equal to 0.1% of the projected area of ​​the first wall 110 on the projected surface, thereby increasing the effective flow area of ​​the conductive portion 22 and the pole body 1201, increasing the flow area of ​​the first pole 12, and improving the flow capacity of the first pole 12, which is beneficial to improving the charging speed of the battery cell 10. At the same time, it is also beneficial to improve the thermal diffusion capacity of the first pole 12 to a certain extent, reduce the overcurrent temperature of the first pole 12, and thus help reduce the risk of loss of control of the battery cell 10.

[0442] In some embodiments, along a direction perpendicular to the projection plane, a projection area of ​​the first welding portion 71 on the projection plane is greater than or equal to 0.15% of a projection area of ​​the first wall 110 on the projection plane.

[0443] In the above technical solution, the orthographic projection area of ​​the first welding portion 71 on the projection surface is set to be greater than or equal to 0.15% of the orthographic projection area of ​​the first wall 110 on the projection surface, so as to further increase the effective flow area between the conductive portion 22 and the pole body 1201, thereby facilitating the improvement of the fast charging performance of the battery cell 10.

[0444] In some embodiments, the projection area of ​​the first welding portion 71 on the projection surface is greater than or equal to 5 mm. 2 For example, the projection area of ​​the first welding portion 71 on the projection surface can be 5mm 2 , 6mm 2 , 8mm 2 , 9mm 2 , or 10mm 2 etc.

[0445] In the above technical solution, by setting the projection area of ​​the first welding portion 71 on the projection surface to be greater than or equal to 5mm 2 , so as to effectively improve the current carrying capacity and heat diffusion capacity of the first pole 12.

[0446] For example, in the example of FIG59 , the projection of the first weld portion 71 on the projection surface extends into a long strip (the corresponding weld is a spiral long strip). Taking the projection of the first weld portion 71 on the projection surface extending along a straight line as an example, the length of the projection of the first weld portion 71 on the projection surface is greater than or equal to 10 mm, and the width of the projection of the first weld portion 71 on the projection surface is greater than or equal to 5 mm. Of course, the projection of the first weld portion 71 on the projection surface can also extend along a curve (including but not limited to such a smooth curve or a broken line). For example, the projection of the first weld portion 71 on the projection surface extends into a closed ring (e.g., a circular ring, a polygonal ring, etc.). In addition, the shape of the projection of the first weld portion 71 on the projection surface can also be a solid circle.

[0447] Furthermore, the projection area of ​​the first welding portion 71 on the projection surface is greater than or equal to 7 mm 2 For example, the projection area of ​​the first welding portion 71 on the projection surface can be 7mm 2 , 7.8mm 2 , 9.5mm 2 , or 11mm 2 etc.

[0448] For example, taking the case where the projection of the first welding portion 71 on the projection plane is a solid circle, the diameter of the circle corresponding to the projection of the first welding portion 71 on the projection plane is greater than or equal to 3 mm.

[0449] In some embodiments, the overlapping portion of the conductive part 22 and the pole body 1201 along the direction perpendicular to the projection plane is the weldable area of ​​the conductive part 22; that is, the weldable area of ​​the conductive part 22 is overlapped with the pole body 1201 along the direction perpendicular to the projection plane, or in other words, along the direction perpendicular to the projection plane, the projection of the weldable area of ​​the conductive part 22 on the projection plane overlaps at least partially with the projection of the pole body 1201 on the projection plane; then the weldable area of ​​the conductive part 22 can be understood as the area provided by the conductive part 22 that can be welded to the pole body 1201, then the area of ​​the weldable area must be greater than or equal to the positive projection area of ​​the first welding part 71 on the projection plane.

[0450] Among them, along the direction perpendicular to the projection plane, the projected area of ​​the first welding portion 71 on the projection plane is greater than or equal to 20% of the area of ​​the weldable area of ​​the conductive portion 22, then the projected area of ​​the first welding portion 71 on the projection plane has a suitable proportion, so as to facilitate the welding operation between the conductive portion 22 and the pole body 1201 while appropriately improving the current carrying capacity and heat diffusion capacity of the first pole 12.

[0451] For example, the orthographic projection area of ​​the first welding portion 71 on the projection plane is 20%, 25%, 35%, 40%, 50%, or 60% of the area of ​​the weldable region of the conductive portion 22 .

[0452] In some embodiments, along a direction perpendicular to the projection plane, a projection area of ​​the first welding portion 71 on the projection plane is greater than or equal to 30% of an area of ​​the weldable region of the conductive portion 22 .

[0453] In the above technical solution, by setting the orthographic projection area of ​​the first welding portion 71 on the projection surface to be greater than or equal to 30% of the area of ​​the weldable area of ​​the conductive portion 22, it is beneficial to further balance the current carrying capacity of the first electrode 12 and the convenience of welding operation. For example, the orthographic projection area of ​​the second welding portion 7 on the projection surface is 30%, 45%, 55%, 65%, or 70% of the area of ​​the weldable area of ​​the guide portion 22.

[0454] In some embodiments, the cross-section of the mounting hole 113 is a projection plane. Along the direction perpendicular to the projection plane, the overlapping portion of the second gathered portion 2213 with the first pole 12 is the weldable area of ​​the pole ear portion 221. The weldable area of ​​the pole ear portion 221 overlaps with the first pole 12 along the direction perpendicular to the projection plane. In other words, along the direction perpendicular to the projection plane, the orthographic projection of the weldable area of ​​the pole ear portion 221 on the projection plane overlaps with at least part of the orthographic projection of the first pole 12 on the projection plane. The weldable area of ​​the pole ear portion 221 can be understood as the area provided by the pole ear portion 221 that can be welded to the first pole 12. Then, the area of ​​the weldable area of ​​the pole ear portion 221 must be greater than or equal to the orthographic projection area of ​​the first welding portion 71 on the projection plane.

[0455] The area of ​​the weldable region of the pole lug 221 is greater than or equal to 40% of the total area of ​​the pole lug 221, so that the pole lug 221 can provide a sufficient weldable region to lay a foundation for improving the current carrying capacity and heat dissipation capacity of the first pole 12. For example, the area of ​​the weldable region of the pole lug 221 is 40%, 45%, 50%, 65%, or 70% of the total area of ​​the pole lug 221, etc.

[0456] In some embodiments, the area of ​​the weldable region of the pole lug 221 is greater than or equal to 60% of the total area of ​​the pole lug 221. In the above technical solution, by setting the area of ​​the weldable region of the pole lug 221 to be greater than or equal to 60% of the total area of ​​the pole lug 221, the pole lug 221 can further provide a sufficient weldable region, thereby laying a foundation for improving the current carrying capacity and heat dissipation capacity of the first pole column 12. For example, the area of ​​the weldable region of the pole lug 221 is 60%, 68%, 72%, or 80% of the total area of ​​the pole lug 221, etc.

[0457] In some embodiments, as shown in Figures 62 to 66, the conductive portion 22 includes a pole ear portion 221 and an adapter plate 222. The connection and setting of the adapter plate 222 refer to the above text. Along the direction perpendicular to the projection plane, the overlapping portion of the adapter plate 222 and the first pole 12 is the weldable area of ​​the adapter plate 222. The weldable area of ​​the adapter plate 222 is overlapped with the first pole 12 along the direction perpendicular to the projection plane, or in other words, along the direction perpendicular to the projection plane, the orthographic projection of the weldable area of ​​the adapter plate 222 on the projection plane overlaps with at least part of the orthographic projection of the first pole 12 on the projection plane; then the weldable area of ​​the adapter plate 222 can be immediately the area provided by the adapter plate 222 that can be welded to the first pole 12, then the area of ​​the weldable area of ​​the adapter plate 222 must be greater than or equal to the orthographic projection area of ​​the first welding portion 71 on the projection plane.

[0458] The area of ​​the weldable region of the adapter plate 222 is greater than or equal to 1 / 12 of the area of ​​the adapter plate 222 , so that the adapter plate 222 can provide sufficient weldable region to lay a foundation for improving the current carrying capacity and heat diffusion capacity of the first pole 12 .

[0459] For example, the area of ​​the weldable region of the transfer plate 222 is 1 / 11, 1 / 10, 1 / 9, or 1 / 8 of the total area of ​​the transfer plate 222 .

[0460] In some embodiments, the pole ear portion 221 is indirectly electrically connected to the first pole 12 through the adapter plate 222, and the weldable area of ​​the conductive portion 22 is the weldable area of ​​the adapter plate 222. In the direction perpendicular to the projection plane, the projection area of ​​the first welding portion 71 on the projection plane is greater than or equal to 20% of the area of ​​the weldable area of ​​the adapter plate 222.

[0461] In some embodiments, the area of ​​the weldable region of the transfer plate 222 is greater than or equal to 1 / 10 of the area of ​​the transfer plate 222 .

[0462] In the above technical solution, the area of ​​the weldable region of the adapter plate 222 is set to be greater than or equal to 1 / 10 of the area of ​​the adapter plate 222, so as to further provide the adapter plate 222 with sufficient weldable region, thereby laying a foundation for improving the current carrying capacity and heat dissipation capacity of the first electrode 12. For example, the area of ​​the weldable region of the adapter plate 222 is 1 / 10, 1 / 7, 1 / 6, or 1 / 5 of the total area of ​​the adapter plate 222.

[0463] In some embodiments, as shown in Figure 56, all the first poles 12 of the battery cell 10 are arranged on the same wall of the shell 11, and all the first poles 12 are arranged on the first wall 110, so that the welding of the active material coating part 21 and the corresponding first pole 12 can be carried out on the same side of the shell 11, which simplifies the operational convenience.

[0464] It is understandable that when all the first poles 12 of the battery cell 10 are arranged on the first wall 110, the first wall 110 can be the wall with the largest area of ​​the shell 11, or the area of ​​the first wall 110 is smaller than the area of ​​the wall with the largest area of ​​the shell 11.

[0465] In some embodiments, as shown in FIG56 , the housing 11 includes a body 111 and a cover 112. The body 111 is open at one end, and the cover 112 fits within the open end of the body 111. The terminals 12 are located at the end of the body 111 away from the cover 112. The end of the body 111 away from the cover 112 can be understood as referring to the end of the body 111 opposite the cover 112. During assembly of the battery cell 10, the cell assembly 2 enters the body 111 from the open end. At this point, the conductive portion 22 can contact and be installed with the terminal 12 along the direction in which the cell assembly 2 enters the housing. This process facilitates the installation of the conductive portion 22 and the terminal 12, improving assembly efficiency.

[0466] Optionally, the shell cover 112 may be formed as a flat plate structure, or may be formed as a cover structure that is open toward one end of the shell body 111 .

[0467] In some embodiments, all the first poles 12 of the battery cells 10 are respectively disposed on different walls of the housing 11 to facilitate flexible arrangement of the battery cells 10 and other electrical connection components.

[0468] Specifically, as shown in FIG56 , the housing 11 has a second wall 120. The second wall 120 can be opposite to the first wall 110 and spaced apart, or arranged at an angle thereto. The second wall 120 is formed with a second mounting hole 114. In this case, the plurality of first poles 12 can include first polarity poles 12A and second polarity poles 12B of different polarities. The first polarity pole 12A is disposed in the mounting hole 113, and the second polarity pole 12B of opposite polarity to the first polarity pole 12A is disposed in the second mounting hole 114. Similarly, one of the first polarity pole 12A and the second polarity pole 12B is a positive pole, and the other is a negative pole. The second wall 120 can be adjacent to the first wall 110 and non-parallel, or it can be non-adjacent to the first wall 110. In this case, the second wall 120 can be parallel or non-parallel to the first wall 110. The first polarity pole 12A and the second polarity pole 12B are disposed on different walls of the housing 11.

[0469] More specifically, all the first poles 12 of the battery cell 10 are respectively arranged on two opposite walls of the shell 11, or all the first poles 12 of the battery cell 10 are respectively arranged on two adjacent walls of the shell 11; of course, all the first poles 12 of the battery cell 10 can also be respectively arranged on three or more walls of the shell 11.

[0470] In this case, the battery cell assembly 2 includes one active material coating portion 21 or multiple electrically connected active material coating portions 21; the battery cell assembly 2 also includes two conductive portions 22 of opposite polarity, one of the two conductive portions 22 being electrically connected to the first polarity pole 12A, and the other of the two conductive portions 22 being electrically connected to the second polarity pole 12B, via a first welding portion 71. It can be seen that when the battery cell assembly 2 includes multiple active material coating portions 21, the multiple active material coating portions 21 can be connected in parallel between the first polarity pole 12A on the first wall 110 and the second polarity pole 12B on the second wall 120, thereby increasing the capacity of the battery cell 10.

[0471] Taking the surface where the cross section of the second mounting hole 114 is located as the projection surface, along the direction perpendicular to the projection surface, the projection area of ​​the first welding portion 71 corresponding to the second polarity pole 12B on the projection surface is greater than or equal to 0.03% of the projection area of ​​the second wall 120 on the projection surface, so as to increase the overflow area and overflow capacity of the second polarity pole 12B on the second wall 120, thereby further facilitating the improvement of the charging speed of the battery cell 10, and at the same time, also facilitating the reduction of the overflow temperature of the second polarity pole 12B, so as to further reduce the risk of loss of control of the battery cell 10.

[0472] Obviously, no matter how many active material coating parts 21 of the battery cell assembly 2 are, the two conductive parts 22 of each battery cell assembly 2 are electrically connected to the corresponding active material coating parts 21, and one of the conductive parts 22 of each battery cell assembly 2 is electrically connected to the first polarity pole 12A on the first wall 110 through the first welding part 71, and the other conductive part 22 is electrically connected to the second polarity pole 12B on the second wall 120 through another first welding part 71.

[0473] Therefore, in the above technical solution of the present application, the arrangement of the first polarity pole 12A and the second polarity pole 12B is relatively flexible, which facilitates the battery cell 10 to meet different layout requirements.

[0474] In some embodiments, as shown in FIG90 to FIG73 , the mounting hole 113 includes a plurality of spaced-apart sub-holes 1131 , the first polarity pole 12A includes a plurality of first poles 12 , and the plurality of first poles 12 are disposed in a one-to-one correspondence in the plurality of sub-holes 1131 ; the battery cell assembly 2 includes a plurality of active material coating portions 21 , and the conductive portion 22 includes a plurality of conductive sub-portions connected to the plurality of active material coating portions 21 in a one-to-one correspondence, and each conductive sub-portion is electrically connected to a first pole 12 via a welding portion 71 ;

[0475] Taking the cross-sectional surface of the mounting hole 113 as the projection surface, along the direction perpendicular to the projection surface, the sum of the projection areas of the plurality of welding sections 71 on the projection surface is greater than or equal to 0.1% of the projection area of ​​the first wall 110 on the projection surface, so as to improve the current carrying capacity of the first polarity pole 12A.

[0476] At this time, the arrangement of the second polarity posts 12B of the battery cell 10 can be set according to actual needs. For example, in the example of Figure 71, multiple first polarity posts 12 are arranged in a one-to-one correspondence with multiple sub-holes 1131 of the mounting hole 113. The housing 11 also forms a second mounting hole 114, which also includes multiple spaced sub-holes 1131. The second polarity posts 12B include multiple second polarity posts 15, which are arranged in a one-to-one correspondence with the multiple sub-holes 1131 of the second mounting hole 114. In this case, the second polarity posts 12B can be arranged on the same wall of the housing 11 as the first polarity posts 12A, or on different walls.

[0477] Of course, in other embodiments of the present application, the mounting hole 113 includes a sub-hole 1131, the first polarity pole 12A includes a first pole 12, the second mounting hole 114 also includes a sub-hole 1131, and the second polarity pole 12B includes a second pole 15. It is understood that for a battery cell 10, the number of first poles 12 and the number of second poles 15 can be equal or different.

[0478] In some embodiments, all poles are respectively arranged on two opposite walls of the housing 11 , and poles are respectively arranged on the first wall 110 and the wall of the housing 11 opposite to the first wall 110 , so as to realize flexible arrangement of the poles.

[0479] In some embodiments, as shown in Figures 67 to 72, the outer contour of the cross section of the first polarity pole 12A is rectangular, runway-shaped, or elliptical. The cross section of the first polarity pole 12A can be perpendicular to the axial direction of the mounting hole 113, which facilitates the flexible setting of the outer contour of the first polarity pole 12A. At the same time, the length of the cross section of the first polarity pole 12A is greater than its width, which is conducive to achieving a good match between the first polarity pole 12A and the first wall 110 in the length direction of the cross section of the first polarity pole 12A and the width direction of the cross section of the first polarity pole 12A. For example, the first wall 110 is The length of the first polarity pole 12A in the length direction of the cross section is greater than the width of the first wall 110 in the width direction of the cross section of the first polarity pole 12A, thereby increasing the cross-sectional area of ​​the first polarity pole 12A that can be arranged on the first wall 110 to a certain extent, which is beneficial to increasing the cross-sectional area of ​​the first polarity pole 12A within the limited arrangement area on the first wall 110, and further beneficial to increasing the flow area of ​​the first polarity pole 12A, improving the flow capacity of the first polarity pole 12A, and improving the thermal diffusion capacity of the first polarity pole 12A, and further beneficial to improving the charging speed of the battery cell 10.

[0480] At the same time, the outer contour of the cross section of the second polarity pole 12B with opposite polarity to the first polarity pole 12A is rectangular, runway-shaped, or elliptical, which is also conducive to achieving a good match between the second polarity pole 12B and the corresponding wall of the shell 11 (such as the first wall 110 or the second wall 120, etc.) in the length direction of the cross section of the second polarity pole 12B and the width direction of the cross section of the second polarity pole 12B, so as to make full use of the effective layout area of ​​the corresponding wall of the shell 11 to increase the cross-sectional area of ​​the second polarity pole 12B, thereby facilitating the increase of the current capacity of the second polarity pole 12B and the improvement of the charging speed of the battery cell 10.

[0481] The rectangle in the above-mentioned embodiments of the present application can be broadly understood, and the four corners of the rectangle can be transitioned into right angles or rounded corners. The runway shape can be understood as comprising two parallel line segments and two semicircles connecting the two line segments, such as a runway shape. It is understood that the cross-sectional outer contour of the second polarity terminal 12B of the battery cell 10 can be the same as or different from the cross-sectional outer contour of the first polarity terminal 12A. The first polarity terminal 12A and the second polarity terminal 12B can be located on the same wall of the housing 11, or on different walls of the housing 11.

[0482] In some embodiments, as shown in Figures 56 and 67 to 72, on the cross-section of the first polarity pole 12A, the size of the first polarity pole 12A in the first direction X is greater than or equal to three times the size of the first polarity pole 12A in the second direction Y, and the first direction X, the second direction Y and the axial direction of the mounting hole 113 are perpendicular to each other, which is conducive to achieving a good match between the first polarity pole 12A and the first wall 110 in the first direction X and the second direction Y, so that the first polarity pole 12A fully utilizes the layout area of ​​the first wall 110, so as to increase the cross-sectional area of ​​the first polarity pole 12A within the limited layout area on the first wall 110, so as to facilitate the first polarity pole 12A to be constructed into a "super large pole structure", thereby facilitating increasing the flow area, flow capacity and heat diffusion capacity of the first polarity pole 12A.

[0483] As shown in Figures 56 and 67 to 72, on the cross-section of the second polarity pole 12B, the size of the second polarity pole 12B in the first direction X is greater than or equal to three times the size of the second polarity pole 12B in the second direction Y, and the polarity of the second polarity pole 12B is opposite to that of the first polarity pole 12A. At this time, the second polarity pole 12B and the first polarity pole 12A can be located on the same wall of the shell 11, or the second polarity pole 12B and the first polarity pole 12A are respectively located on two opposite walls of the shell 11, which is conducive to achieving a good match between the second polarity pole 12B and the corresponding walls of the shell 11 in the first direction X and the second direction Y, so that the second polarity pole 12B makes full use of the layout area of ​​the corresponding wall of the shell 11, which is conducive to improving the flow area, flow capacity and heat diffusion capacity of the second polarity pole 12B.

[0484] For example, the size of the first polarity pole 12A in the first direction X can be 3 times, 3.5 times, 4 times, or 4.2 times the size of the first polarity pole 12A on the second defense line, and the size of the second polarity pole 12B in the first direction X can be 3 times, 3.5 times, 3.7 times, or 4.2 times the size of the second polarity pole 12B on the second defense line, etc.

[0485] Exemplarily, the first direction X is the length direction of the cross section of the first polarity pole 12A, and the second direction Y is the width direction of the cross section of the first polarity pole 12A. At this time, the axial direction of the mounting hole 113 can be understood as the height direction of the first polarity pole 12A or the axial direction of the first polarity pole 12A.

[0486] Alternatively, in a cross-section of the second polarity pole 12B, the dimension of the second polarity pole 12B in the axial direction of the mounting hole 113 is greater than or equal to three times the dimension of the second polarity pole 12B in the second direction Y. The polarity of the second polarity pole 12B is opposite to that of the first polarity pole 12A. In this case, the second polarity pole 12B and the first polarity pole 12A can be respectively located on two mutually perpendicular walls of the housing 11. This is also conducive to achieving a good match between the second polarity pole 12B and the corresponding wall of the housing 11 in the axial direction of the mounting hole 113 and in the second direction Y, so that the second polarity pole 12B fully utilizes the layout area of ​​the corresponding wall of the housing 11, which is conducive to improving the flow area, flow capacity, and heat dissipation capacity of the second polarity pole 12B. The axial direction of the mounting hole 113 can be the length direction of the wall where the second polarity pole 12B is located.

[0487] In some embodiments, as shown in Figure 56, the dimension of the first wall 110 in the first direction X is greater than the dimension of the first wall 110 in the second direction Y, then the length direction of the first wall 110 can be consistent with the length direction of the cross section of the first polarity pole 12A, and the width direction of the first wall 110 can be consistent with the width direction of the cross section of the first polarity pole 12A, so as to further achieve a good match between the first wall 110 and the first polarity pole 12A in the first direction X and the second direction Y, so that the first polarity pole 12A can further make full use of the layout area of ​​the first wall 110.

[0488] Exemplarily, a first polarity pole 12A and a second polarity pole 12B are provided on the first wall 110. The first polarity pole 12A and the second polarity pole 12B can be spaced apart along the first direction X, so that the arrangement direction of the first polarity pole 12A and the second polarity pole 12B matches the length direction of the first wall 110, so as to facilitate the first polarity pole 12A and the second polarity pole 12B to have a suitable spacing between them. Of course, the second polarity pole 12B and the first polarity pole 12A can also be respectively arranged on different walls of the shell 11. Taking the shell 11 having a second wall 120 and the second wall 120 provided with the second polarity pole 12B as an example, if the second wall 120 is opposite to the first wall 110 and is spaced apart, the size of the second wall 120 in the first direction X can be larger than the size of the second wall 120 in the second direction Y, so that the second polarity pole 12B can make full use of the layout area provided by the second wall 120. If the second wall 120 is arranged at an angle to the first wall 110, the length direction of the cross section of the second polarity pole 12B can be set to be consistent with the length direction of the second wall 120, and the width direction of the cross section of the second polarity pole 12B can be consistent with the width direction of the second wall 120, which also facilitates the second polarity pole 12B to make full use of the layout area pro...

Claims

1. A battery cell, wherein: include: A housing assembly (1) comprises a housing (11) and a first pole (12), wherein the first pole (12) comprises a pole body (1201) and a first cover plate (13), wherein the pole body (1201) is mounted on the housing (11), and the first cover plate (13) is arranged on the pole body (1201); A battery cell assembly (2), comprising an active material coating portion (21) and a conductive portion (22) connected to the active material coating portion (21), wherein the active material coating portion (21) is accommodated in the housing (11), and the conductive portion (22) is connected to the pole body (1201) via a first welding portion (71); The first welding portion (71) is at least partially located on a side of the pole body (1201) facing away from the active material coating portion (21), and the first cover plate (13) is used to cover the first welding portion (71).

2. The battery cell according to claim 1, wherein: The pole body (1201) has a first receiving groove (12110); the surface of the first pole (12) facing the active material coating portion (21) is the inner end face (122) of the pole; the notch of the first receiving groove (12110) is formed on the inner end face (122) of the pole; the first receiving groove (12110) has a first end wall (12111) and a first side wall (12113); the first end wall (12111) is located on a side of the first side wall (12113) away from the active material coating portion (21); at least part of the conductive portion (22) is received in the first receiving groove (12110); the first welding portion (71) is provided on the first end wall (12111); the first cover plate (13) cooperates with the pole body (1201) and covers the first welding portion (71).

3. The battery cell (10) according to claim 2, wherein: The first end wall (12111) has a first recessed groove (12112), and at least a portion of the first welding portion (71) is located in the first recessed groove (12112).

4. The battery cell (10) according to claim 2 or 3, wherein: The first pole (12) has a first groove (126); a surface of the first pole (12) away from the active material coating portion (21) is a pole outer end surface (123); a notch of the first groove (126) is formed on the pole outer end surface (123); and the first cover plate covers the notch of the first groove.

5. The battery cell according to any one of claims 2 to 4, wherein: The active material coating portion (21) comprises a current collector (211) and an active material layer (212) disposed on the current collector (211); the conductive portion (22) comprises a pole ear portion (221) electrically connected to the current collector (211); the pole ear portion (221) comprises a plurality of pole ear sheets (2211); the plurality of pole ear sheets (2211) converge at a position close to the current collector (211) to form a first gathered portion (2212); the plurality of pole ear sheets (2211) converge at a position away from the current collector (211) and are connected to form a second gathered portion (2213); the first gathered portion (2212) connects the second gathered portion (2213) and the active material coating portion (21); at least a portion of the second gathered portion (2213) is accommodated in the first accommodation groove (12110); The second gathering portion (2213) is connected to the first end wall (12111) via the first welding portion (71).

6. The battery cell (10) according to any one of claims 2 to 4, wherein: The active material coating portion (21) comprises a current collector (211) and an active material layer (212) disposed on the current collector (211); the conductive portion (22) comprises a pole ear portion (221) and a transfer sheet (222); the pole ear portion (221) comprises a plurality of pole ear sheets (2211); the plurality of pole ear sheets (2211) converge at a position close to the current collector (211) to form a first gathering portion (2212); the plurality of pole ear sheets (2211) converge at a position away from the current collector (211) and are connected to form a second gathering portion (2213); the first gathering portion (2212) connects the second gathering portion (2213) and the active material coating portion (21); the transfer sheet (222) is connected to the second gathering portion (2213); at least a portion of the transfer sheet (222) is accommodated in the first accommodation groove (12110); The adapter plate (222) is connected to the first end wall (12111) via the first welding portion (71).

7. The battery cell (10) according to claim 5 or 6, wherein: At least a portion of the first retracted portion (2212) is accommodated in the first accommodating groove (12110).

8. The battery cell (10) according to any one of claims 2 to 7, wherein: The housing (11) has a mounting hole (113), and the first pole (12) is mounted in the mounting hole (113); along the axial direction of the first pole (12), a depth H1 of the first accommodating groove (12110) is greater than or equal to a minimum distance H2 from an inner end surface (122) of the pole to the mounting hole (113).

9. The battery cell according to claim 1, wherein: The pole body (1201) has a second receiving groove (12120); the surface of the pole body (1201) on the side away from the active material coating portion (21) is the pole outer end surface (123); the notch of the second receiving groove (12120) is formed on the pole outer end surface (123); the second receiving groove (12120) has a second end wall (12121) close to the active material coating portion (21); The first welding portion (71) is disposed on the second end wall (12121), and the first cover plate (13) cooperates with the pole body (1201) and covers the notch of the second receiving groove (12120).

10. The battery cell according to claim 9, wherein: The conductive portion (22) is located on a side of the second end wall (12121) facing the active material coating portion (21).

11. The battery cell according to claim 9, wherein: The second receiving groove (12120) is connected to the interior of the shell (11) through the first through hole (12130), the conductive part (22) is passed through the first through hole (12130) and is at least partially received in the second receiving groove (12120), and the conductive part (22) is at least partially arranged on a side of the second end wall (12121) facing away from the active material coating part (21).

12. The battery cell according to claim 11, wherein: The second containing groove (12120) further comprises a second side wall (12123), the second side wall (12123) being located on a side of the second end wall (12121) away from the active material coating portion (21), and the second side wall (12123) and the second end wall (12121) are arranged to form the second containing groove (12120), the first through hole (12130) being opened on the second end wall (12121), The second end wall (12121) has a second recessed groove (12122), and at least a portion of the first welding portion (71) is located in the second recessed groove (12122).

13. The battery cell (10) according to claim 11 or 12, wherein: The active material coating portion (21) comprises a current collector (211) and an active material layer (212) disposed on the current collector (211); the conductive portion (22) comprises a pole ear portion (221) electrically connected to the current collector (211); the pole ear portion (221) comprises a plurality of pole ear sheets (2211); the plurality of pole ear sheets (2211) converge at a position close to the current collector (211) to form a first gathered portion (2212); the plurality of pole ear sheets (2211) converge at a position away from the current collector (211) and are connected to form a second gathered portion (2213); the first gathered portion (2212) connects the second gathered portion (2213) and the active material coating portion (21); at least a portion of the second gathered portion (2213) is accommodated in the second accommodation groove (12120); The second gathering portion (2212) is connected to the second end wall (12121) via the first welding portion (71).

14. The battery cell (10) according to claim 11 or 12, wherein: The active material coating portion (21) comprises a current collector (211) and an active material layer (212) disposed on the current collector (211); the conductive portion (22) comprises a pole ear portion (221) and a transfer sheet (222); the pole ear portion (221) is electrically connected to the current collector (211); the pole ear portion (221) comprises a plurality of pole ear sheets (2211); the plurality of pole ear sheets (2211) converge near the current collector (211) to form a first A gathering portion (2212), a plurality of the electrode tabs (2211) are gathered at a position away from the current collector (211) and connected to form a second gathering portion (2213), the first gathering portion (2212) is connected to the second gathering portion (2213) and the active material coating portion (21), the adapter sheet (222) is connected to the second gathering portion (2213), and at least a portion of the adapter sheet (222) is accommodated in the second accommodation groove (12120), The adapter plate (222) is connected to the second end wall (12121) via the first welding portion (71).

15. The battery cell according to claim 13 or 14, wherein: At least a portion of the first retracted portion (2212) is accommodated in the second accommodating groove (12120).

16. The battery cell (10) according to claim 13 or 14, wherein: The pole body (1201) is provided with a first accommodating portion (121), the first accommodating portion (121) having a third accommodating groove (12140), the surface of the first pole (12) facing the active material coating portion (21) is the pole inner end face (122), the third accommodating groove (12140) is located on the side of the second accommodating groove (12120) close to the active material coating portion (21), and the notch of the third accommodating groove (12140) is formed on the pole inner end face (122), the third accommodating groove (12140) is connected with the second accommodating groove (12120) through the first through hole (12130), and at least a part of the first retracted portion (2212) is accommodated in the third accommodating groove (12140).

17. The battery cell according to any one of claims 11 to 16, wherein: The housing assembly (1) further comprises a second cover plate (14), wherein the second cover plate (14) covers the first through hole (12130) and the outside of the conductive portion (22) located in the second receiving groove (12120).

18. The battery cell (10) according to any one of claims 9 to 17, wherein: The housing (11) has a mounting hole (113), the first pole (12) is mounted in the mounting hole (113), and along the axial direction of the first pole (12), the depth H3 of the second accommodating groove (12120) is greater than or equal to the minimum distance H4 from the outer end surface (123) of the pole to the mounting hole (113).

19. The battery cell according to claim 1, wherein: The pole body (1201) is provided with a first accommodating portion (121), the first accommodating portion (121) having a fourth accommodating groove (12150), the surface of the pole body (1201) away from the active material coating portion (21) is the pole outer end surface (123), the notch of the fourth accommodating groove (12150) is formed on the pole outer end surface (123), the fourth accommodating groove (12150) is connected to the interior of the housing (11) through a second through hole (12160), and the conductive portion (22) is provided through the second through hole (12160), The first welding portion (71) is arranged on the hole wall of the second through hole (12160) formed by the first accommodating portion (121), and the first cover plate (14) cooperates with the pole body (1201) and covers the second through hole (12160).

20. The battery cell (10) according to claim 19, wherein: The pole body (1201) comprises a first pole portion (124) and a second pole portion (125) made of different materials and electrically connected, the second pole portion (125) being located on a side of the first pole portion (124) away from the active material coating portion (21), the first accommodating portion (121) being arranged on the first pole portion (124) or on the first pole portion (124) and the second pole portion (125), and the first welding portion (71) being arranged on the first pole portion (124).

21. The battery cell according to any one of claims 1 to 20, wherein: The first cover plate (13) is provided with a second accommodating portion (134), the second accommodating portion (134) having a fifth accommodating groove (1341), the notch of the fifth accommodating groove (1341) being formed on an end surface of the first cover plate (13) facing the active material coating portion (21), and the fifth accommodating groove (1341) having a third end wall (13411) and a third side wall (13412), the third end wall (13411) being located on a side of the third side wall (13412) away from the active material coating portion (21), At least a portion of the first welding portion (71) is accommodated in the fifth accommodation groove (1341).

22. The battery cell (10) according to any one of claims 1 to 21, wherein: The first cover plate (13) is electrically connected to the pole body (1201); or the first cover plate (13) is insulated from the pole body (1201).

23. The battery cell (10) according to any one of claims 1 to 21, wherein: The first cover plate (13) comprises a first conductive member (131) and a second conductive member (132) made of different materials; the first conductive member (131) cooperates with and is electrically connected to the pole body; the second conductive member (132) cooperates with and is electrically connected to the first conductive member (131).

24. The battery cell (10) according to claim 23, wherein: The first conductive member (131) has a second groove (1311), and the second conductive member (132) is embedded in the second groove (1311). The notch of the second groove (1311) is formed on the surface of the first conductive member (131) away from the active material coating portion (21), so that the second conductive member (132) is exposed from the notch of the second groove (1311).

25. The battery cell (10) according to any one of claims 23 or 24, wherein: The first cover plate (13) is provided with a stress release groove (133), and the stress release groove (133) is located in the outer peripheral area of ​​the first cover plate (13).

26. The battery cell (10) according to any one of claims 2-4, 9-12, and 19, wherein: Also includes: A bracket (3) is located inside the housing (11) and on a side of the active material coating portion (21) close to the first pole (12); the bracket (3) has an avoidance hole (31) for avoiding the conductive portion (22); the conductive portion (22) is suitable for extending to a side of the bracket (3) away from the active material coating portion (21) through the avoidance hole (31).

27. The battery cell (10) according to claim 26, wherein: The pole body (1201) is provided with a first accommodating portion (121), the bracket (3) is provided with a guiding portion (32), the guiding portion (32) surrounds and forms at least a portion of the avoidance hole (31), and the guiding portion (32) at least partially extends to the first accommodating portion (121).

28. The battery cell (10) according to claim 26 or 27, wherein: The avoidance hole (31) comprises a first hole segment (311) and a second hole segment (312), the second hole segment (312) being located on a side of the first hole segment (311) close to the active material coating portion (21), and the cross-sectional area of ​​the second hole segment (312) gradually increases in a direction away from the first hole segment (311), the active material coating portion (21) comprises a current collector (211) and an active material layer (212) disposed on the current collector (211), the conductive portion (22) comprises a pole ear portion (221) electrically connected to the current collector (211), the pole ear portion (221) The invention comprises a plurality of pole lugs (2211), wherein the plurality of pole lugs (2211) converge at positions close to the current collector (211) to form a first gathered portion (2212), and the plurality of pole lugs (2211) converge at positions away from the current collector (211) and are connected to form a second gathered portion (2213), wherein the first gathered portion (2212) connects the second gathered portion (2213) and the active material coating portion (21), wherein at least a portion of the first gathered portion (2212) is accommodated in the second hole segment (312), and the second gathered portion (2213) is penetrated through the first hole segment (311).

29. The battery cell (10) according to any one of claims 26 to 28, wherein: The bracket (3) is an integrated structure; or, the bracket (3) is a split structure and comprises a detachable first bracket (33) and a second bracket (34), wherein the avoidance hole (31) is defined between the first bracket (33) and the second bracket (34).

30. The battery cell according to any one of claims 1 to 29, wherein: The shell (11) has a first wall (110), the first wall (110) is formed with a mounting hole (113), the pole body (1201) is arranged in the mounting hole (113), and the plane where the cross section of the mounting hole (113) is located is taken as the projection plane. Along the direction perpendicular to the projection plane, the ratio of the projection area of ​​the first welding part (71) on the projection plane to the projection area of ​​the first wall (110) on the projection plane is in the range of 0.1% to 1%.

31. The battery cell according to any one of claims 1 to 30, wherein: The shell (11) has a mounting hole (113), and the pole body (1201) comprises an integrally formed pole body portion (12a), a first limiting platform portion (12b) and a second limiting platform portion (12c); the pole body portion (12a) is inserted into the mounting hole (113), the first limiting platform portion (12b) and the second limiting platform portion (12c) are arranged at two ends of the pole body portion (12a) along the axial direction of the mounting hole (113); the first limiting platform portion (12b) is limitedly matched with the outer side of the shell (11), and the second limiting platform portion (12c) is limitedly matched with the inner side of the shell (11), so that the pole body (1201) is riveted to the shell (11).

32. The battery cell according to any one of claims 1 to 31, wherein: The battery cell (10) further comprises: An external insulating member (5), wherein the external insulating member (5) is wrapped outside the shell (11).

33. The battery cell according to claim 32, wherein: The shell (11) has a first wall (110), the first wall (110) is formed with a mounting hole (113), the pole body (1201) is arranged in the mounting hole (113), the battery cell (10) also includes a patch (9) covering the outside of the first wall (110), the external insulating member (5) includes an external insulating film (52), the external insulating film (52) is an integrated film, and the external insulating film (52) has a connecting portion (51), the connecting portion (51) extends to the outside of the first wall (110) and is connected to the patch (9).

34. The battery cell according to claim 33, wherein: The minimum distance between the edge of the outer insulating film (52) and the first pole (12) is greater than or equal to 3 mm.

35. A battery, wherein: A battery cell (10) comprising the battery cell (10) according to any one of claims 1 to 34.

36. The battery according to claim 35, wherein include: A plurality of said battery cells (10); A current collecting component (30), the current collecting component (30) being electrically connected to the first poles (12) of at least two of the battery cells (10), the first poles (12) of the same polarity of each of the battery cells (10) being electrically connected to the current collecting component (30) via second welding portions (72), the second welding portions (72) being formed on the first cover plate (13); The shell (11) includes a first wall (110), the first wall (110) is formed with a mounting hole (113), the pole body (1201) is arranged in the mounting hole (113), and on the cross section of the mounting hole (113), the orthographic projection area of ​​the second welding portion (72) is greater than or equal to 0.2% of the orthographic projection area of ​​the first wall (110).

37. The battery according to claim 36, wherein Along a direction perpendicular to the cross section of the mounting hole (113), the overlapping portion of the current collecting component (30) and the pole body (12) of the same polarity is a weldable area of ​​the current collecting component (30). The orthographic projection area of ​​the second welding portion (72) on the cross section of the mounting hole (113) is greater than or equal to 0.2 of the weldable area of ​​the collector component (30).

38. The battery according to claim 36, wherein Along a direction perpendicular to the cross section of the mounting hole (113), the overlapping portion of the current collecting component (30) and the first pole (12) of the same polarity is a weldable area of ​​the current collecting component (30). The area of ​​the weldable region of the collector component (30) is greater than or equal to 20% of the orthographic projection area of ​​the collector component (30) on the cross section of the mounting hole (113).

39. The battery according to claim 38, wherein The area of ​​the weldable region of the collector component (30) is less than or equal to 50% of the orthographic projection area of ​​the collector component (30) on the cross section of the mounting hole (113).

40. An electrical device, wherein: Comprising a battery (100) according to any one of claims 35-39.

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