Battery monomer, battery and electric device

Abstract

The invention discloses a single battery, a battery and a power utilization device, the single battery comprises a shell assembly and a battery cell assembly, the shell assembly comprises a shell and a first pole, the shell is provided with a first wall, a mounting hole is formed in the first wall, the first pole is arranged in the mounting hole, the first pole comprises a first welding surface, and the first welding surface is provided with a second welding surface; the battery cell assembly comprises an active substance coating part and a conductive part electrically connected with the active substance coating part, the active substance coating part is accommodated in the shell, the conductive part comprises a second welding surface in contact with the first welding surface, and a part of the second welding surface is welded with a part of the first welding surface through a welding part; the plane where the cross section of the mounting hole is located serves as a projection plane, and the outer contour of the projection of the second welding face on the projection plane is located in the outer contour range of the projection of the first welding face on the projection plane in the direction perpendicular to the projection plane. According to the battery monomer provided by the invention, the fast charging performance, the reliability and the stability of the battery monomer are 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 of electric vehicles, play an irreplaceable and important role. Batteries typically consist of multiple cells, and current cell charging speeds are difficult to increase, limiting their use in vehicles.

[0003] Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the related art. To this end, the present application proposes a battery cell, a battery and an electrical device with a relatively fast charging speed.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising: a shell assembly, comprising a shell and a first pole, the shell having a first wall, the first wall forming a mounting hole, the first pole being arranged in the mounting hole, and the first pole comprising a first welding surface; a battery cell assembly, comprising an active material coating portion and a conductive portion electrically connected to the active material coating portion, the active material coating portion being accommodated in the shell, the conductive portion comprising a second welding surface welded to the first welding surface, and a portion of the second welding surface being welded to a portion of the first welding surface through the welding portion; wherein, with the surface where the cross section of the mounting hole is located as the projection surface, along a direction perpendicular to the projection surface, the outer contour of the projection of the second welding surface on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface.

[0006] In the above technical solution, by setting the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, the outer contour of the projection of the second welding surface on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface, and the area of ​​the first pole that can be welded to the conductive part is larger than the area of ​​the conductive part that can be welded to the first pole, so as to realize the oversized setting of the first pole. On the one hand, when the size of the conductive part remains unchanged, enlarging the first pole can ensure the flow area of ​​the conductive part and increase the flow area of ​​the first pole; at the same time, the oversized setting of the first pole can make the bus assembly electrically connected to the first pole be set relatively large, so that the area of ​​the bus assembly used for electrical connection (for example, welding) with the first pole can be set larger, and the flow area of ​​the bus assembly can also be increased. At the same time, the increase in the flow area of ​​the conductive part, the first pole and the bus assembly can not only reduce the resistance and improve the temperature rise during the charging and discharging process to improve the reliability of the battery cell, but also increase the current to enhance the fast charging performance of the battery cell; on the other hand, the extra-large setting of the first pole can provide a larger welding space, which can increase the welding space between the first pole and the conductive part, and increase the welding space between the first pole and the bus assembly, so that the welding reliability and stability are higher, which can further improve the reliability and stability of the battery cell.

[0007] In some embodiments, the first pole includes a pole body, a first limit platform and a second limit platform. The pole body is passed through the mounting hole, and the first limit platform and the second limit platform are arranged at both ends of the pole body in a direction perpendicular to the projection plane, and the first limit platform is limited to the outer side of the shell, and the second limit platform is limited to the inner side of the shell; the second limit platform is close to the end face of the battery cell assembly to form a first welding surface.

[0008] In the above technical solution, the structure of the first pole includes a pole body, a first limit platform and a second limit platform, so that the first pole can be riveted to the shell, which facilitates the assembly of the first pole and the shell, simplifies the manufacturing process, and improves the reliability and stability of the connection between the first pole and the shell; at the same time, by riveting the first pole to the shell, it is easy to achieve a reliable connection between the first pole and the shell without adopting other connection methods, which is conducive to simplifying the structure of the shell assembly and simplifying the assembly process of the shell assembly.

[0009] In some embodiments, the length dimension of the pole body in the first direction is greater than or equal to 1 / 3 of the length dimension of the first wall in the first direction; and / or, the width dimension of the pole body in the second direction is greater than or equal to 1 / 2 of the width dimension of the first wall in the second direction; and / or, the ratio of the circumference of the circumference of the pole body in the mounting hole to the circumference of the first wall is within the range of 25% to 40%; and / or, the cross-sectional area of ​​the portion of the pole body that cooperates with the mounting hole is greater than or equal to 10% of the area of ​​the first wall; and / or, along the axial direction of the mounting hole, the ratio of the thickness dimension of the pole body to the thickness dimension of the first wall is greater than 1 and less than 1.5.

[0010] In the above technical solution, when at least one of the ratio of the length of the pole body to the length of the first wall, the ratio of the width of the pole body to the width of the first wall, and the ratio of the circumference of the pole body and the mounting hole to the circumference of the first wall meets the above corresponding range, the pole body accounts for a large proportion in the length and width directions of the first wall, and the size of the matching part of the pole body and the mounting hole is large, which can improve the stability of the riveting between the first pole and the first wall, ensure the riveting strength of the first pole, and improve the reliability and stability of the battery cell; when the cross-sectional area of ​​the pole body and the area of ​​the first wall are within the above range, the flow area of ​​the first pole is large, which can improve the flow and fast charging capabilities of the first pole; when the thickness of the pole body and the thickness of the first wall meet the above corresponding range, it is convenient for the pole body to be reliably matched with the mounting hole, so that the first limit platform and the second limit platform are respectively located on the inner and outer sides of the shell, so as to achieve smooth riveting of the first pole and improve the riveting convenience and riveting reliability.

[0011] In some embodiments, the ratio of the length dimension of the first limit platform in the first direction to the length dimension of the first wall in the first direction is in the range of 1 / 3 to 1 / 2; and / or, the ratio of the width dimension of the first limit platform in the second direction to the width dimension of the first wall in the second direction is in the range of 1 / 2 to 3 / 4; and / or, the first limit platform is columnar, and the ratio of the circumference dimension of the outer periphery of the first limit platform to the circumference dimension of the first wall is in the range of 30% to 50%; and / or, the ratio of the cross-sectional area of ​​the first limit platform to the area of ​​the first wall is in the range of 9% to 25%; and / or, along the axial direction of the mounting hole, the ratio of the thickness dimension of the first limit platform to the thickness dimension of the first wall is in the range of 0.6 to 1.5.

[0012] In the above technical solution, when at least one of the ratio of the length of the first limit platform to the length of the first wall, the ratio of the width of the first limit platform to the width of the first wall, and the ratio of the circumference of the first limit platform to the circumference of the first wall meets the above corresponding ranges, the first limit platform accounts for a large proportion in the length and width directions of the first wall, and the size of the matching part of the first limit platform and the mounting hole is large, which can improve the stability of the riveting between the first pole and the first wall, ensure the riveting strength of the first pole, and thus improve the reliability and stability of the battery cell; when the ratio of the cross-sectional area of ​​the first limit platform to the area of ​​the first wall is within the above range, the flow area of ​​the first pole is large, which can improve the flow and fast charging capabilities of the first pole; when the ratio of the thickness of the first limit platform to the thickness of the first wall meets the above corresponding range, it is easy to avoid the first pole from being easily separated from the first wall, further improve the riveting reliability, and is conducive to reducing the thickness of the part of the first limit platform protruding outside the shell, reducing the space occupied by the first pole outside the shell, and is conducive to improving the volume energy density of the battery.

[0013] In some embodiments, the ratio of the length dimension of the second limit platform in the first direction to the length dimension of the first wall in the first direction is in the range of 1 / 3 to 1 / 2; and / or, the ratio of the width dimension of the second limit platform in the second direction to the width dimension of the first wall in the second direction is in the range of 1 / 2 to 3 / 4; and / or, the second limit platform is columnar, and the ratio of the circumference dimension of the outer periphery of the second limit platform to the circumference dimension of the first wall is in the range of 30% to 50%; and / or, the ratio of the cross-sectional area of ​​the second limit platform to the area of ​​the first wall is in the range of 9% to 25%; and / or, along the axial direction of the mounting hole, the ratio of the thickness dimension of the second limit platform to the thickness dimension of the first wall is in the range of 0.6 to 1.5.

[0014] In the above technical solution, when at least one of the ratio of the length of the second limit platform to the length of the first wall, the ratio of the width of the second limit platform to the width of the first wall, and the ratio of the outer circumference of the second limit platform to the circumference of the first wall meets the above corresponding range, the second limit platform accounts for a large proportion in the length and width directions of the first wall, and the size of the matching part of the second limit platform and the mounting hole is large, which can improve the stability of the riveting between the first pole and the first wall, ensure the riveting strength of the first pole, and thus improve the reliability and stability of the battery cell; when the ratio of the cross-sectional area of ​​the second limit platform to the area of ​​the first wall is within the above range, the flow area of ​​the first pole is large, which can improve the flow and fast charging capabilities of the first pole; when the ratio of the thickness of the second limit platform to the thickness of the first wall meets the above corresponding range, it is easy to avoid the first pole from being easily separated from the first wall, further improve the riveting reliability, and is conducive to reducing the thickness of the part of the second limit platform protruding from the shell, reducing the space occupied by the first pole in the shell, and is conducive to improving the volume energy density of the battery cell.

[0015] In some embodiments, the conductive portion includes a plurality of pole tabs connected to the active material coating portion, the plurality of pole tabs are gathered together at one end close to the active material coating portion to form a first gathered portion, the plurality of pole tabs are gathered together at one end away from the active material coating portion and connected to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, and the end face of the second gathered portion on the side close to the first pole forms a second welding surface.

[0016] In the above technical solution, the second welding surface is formed by arranging the end surface of the second gathered portion close to the first pole, which is beneficial to shortening the length of the conductive portion, saving the space occupied by the conductive portion, and facilitating the improvement of the volume energy density of the battery cell.

[0017] In some embodiments, taking the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, at least part of the outer contour of the projection of the first folded portion on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface.

[0018] In the above technical solution, by setting at least a part of the outer contour of the projection of the first folding portion on the projection surface to be located within the outer contour range of the projection of the first welding surface on the projection surface, it is beneficial to save the space occupied by the first folding portion in the axial direction perpendicular to the mounting hole, and to reduce the distance between the first pole and the battery cell assembly in the axial direction of the mounting hole, so as to improve the energy density of the battery cell.

[0019] In some embodiments, the conductive portion includes a plurality of tabs connected to the active material coating portion, and a transfer plate; the plurality of tabs are gathered together at one end close to the active material coating portion to form a first gathered portion, and the plurality of tabs are gathered together and connected at one end away from the active material coating portion to form a second gathered portion, the first gathered portion connects the second gathered portion and the active material coating portion, the transfer plate connects the second gathered portion and the first pole, and the portion of the end face of the transfer plate close to the first pole forms a second welding surface.

[0020] In the above technical solution, an adapter plate is used to achieve indirect electrical connection between the second gathered portion and the first pole. The adapter plate can be welded to the first pole at a position avoiding the second gathered portion, thereby making the welding between the adapter plate and the first pole firm, reducing the risk of welding cracking, and further improving the reliability and stability of the battery cell. At the same time, electrically connecting the first pole and the pole tab through the adapter plate can also simplify the structure of the pole tab.

[0021] In some embodiments, taking the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, at least part of the outer contour of the projection of the second gathered portion on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface; and / or, taking the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, at least part of the outer contour of the projection of the first gathered portion on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface.

[0022] In the above technical solution, by setting the outer contour of the projection of the second gathering part on the projection surface to be at least partially located within the outer contour range of the projection of the first welding surface on the projection surface, and the outer contour of the projection of the first gathering part on the projection surface to be at least partially located within the outer contour range of the projection of the first welding surface on the projection surface, it is beneficial to save the space occupied by the first gathering part and the second gathering part in the axial direction perpendicular to the mounting hole, and to reduce the distance between the first pole and the battery cell assembly in the axial direction of the mounting hole, so as to improve the energy density of the battery cell.

[0023] In some embodiments, the first pole is provided with a receiving portion, and at least a portion of the guide portion is received in the receiving portion.

[0024] In the above technical solution, on the one hand, the first electrode is provided with a receiving portion, 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, by accommodating at least part of the conductive part in the receiving portion to occupy the space in the first electrode, the space occupied by the conductive part in the shell can be reduced. When the size of the shell is fixed, some space can be saved in the shell to accommodate a larger active material coating part, thereby improving the volume energy density of the battery cell; at the same time, accommodating at least part of the conductive part in the receiving portion can reduce the space occupied by the battery cell itself, so that a battery of the same volume can accommodate a larger number of battery cells, thereby also improving the volume energy density of the battery; in addition, accommodating at least part of the conductive part in the receiving portion can also reduce the redundancy of the conductive part in the shell to a certain extent, reduce the probability of short circuit between the conductive part and the active material coating part, reduce the probability of short circuit of the electrode assembly, and thereby improve the working reliability and stability of the battery cell and the battery. In addition, by accommodating at least part of the conductive part in the accommodating part, the conductive part can be limited and constrained by the accommodating part, which is beneficial to improving the reliability of the conductive part, so as to ensure the reliability and stability of the welding between the conductive part and the first pole, thereby improving the reliability of the battery cell.

[0025] In some embodiments, the accommodating portion has a first accommodating 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 accommodating groove is formed on the inner end face of the pole, and at least part of the conductive portion is accommodated in the first accommodating groove.

[0026] In the above technical solution, on the one hand, the first receiving groove is provided on the first pole, which can reduce the weight of the first pole 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 first receiving groove is formed on the inner end face of the pole, and the inner end face of the pole is the surface of the first pole close to the active material coating part, the first receiving groove can be opened toward the active material coating part, thereby facilitating the conductive part to extend into the first receiving groove, thereby improving assembly efficiency; at the same time, since the first receiving groove is toward the active material coating part, the first receiving groove can also serve as a buffer and temporary storage structure for the electrolyte, so that the shell can accommodate It can hold more electrolyte. Since the electrolyte will be lost during the charge and discharge process of the battery cell, when there is more electrolyte, the service life of the battery cell can be extended. And because the first holding tank is facing the active material coating part, the first holding tank can also serve as a holding and buffer structure for the gas generated inside the electrode assembly, reducing the expansion of the battery cell and improving the reliability and stability of the battery cell. In addition, the first holding tank is located on the inner side of the pole, and external foreign matter and impurities are not easy to enter the first holding tank, thereby reducing the impact of external foreign matter and impurities on the electrode assembly, ensuring the stability and reliability of the electrode assembly, and thus improving the stability and reliability of the battery cell and the battery.

[0027] In some embodiments, the wall of the first receiving groove has a first sunken groove, and the position where the conductive portion is electrically connected to the first pole is at least partially located in the first sunken groove.

[0028] In the above technical solution, on the one hand, by arranging the first recessed groove on the first end wall, the first recessed groove can be used to achieve pre-positioning of the conductive part, which is beneficial for finding the correct position to achieve electrical connection and improve production efficiency; on the other hand, by arranging the first recessed groove on the first end wall, the local wall thickness of the first end wall can be locally thinned, which is not only beneficial for welding electrical connection, but also beneficial for reducing the weight of the first pole and improving the weight energy density of the battery cell.

[0029] In some embodiments, the first pole has a first groove, a surface of the first pole away from the active material coating portion is an outer end surface of the pole, and a notch of the first groove is formed on the outer end surface of the pole.

[0030] In the above technical solution, on the one hand, the first electrode is provided with a first groove, which can further reduce the weight of the first electrode, thereby improving 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 electrode, and the first groove can be used to accommodate or install structural components in the battery that electrically connect the various battery cells, thereby fully utilizing the space within the first electrode and improving the space utilization rate and volume energy density of the battery. In addition, because the first electrode has both the first receiving groove and the first groove, the first groove is located on the side of the first receiving groove away from the active material coating portion, and the first groove is open in a direction away from the first receiving groove. This facilitates electrical connection between the conductive portion and the groove wall of the first receiving groove from the outside of the first electrode through the first groove. For example, it is convenient to externally weld the first electrode and the conductive portion through the first groove, which facilitates the processing and manufacturing of the battery cell and can save processing and manufacturing costs.

[0031] In some embodiments, the battery cell further includes a slot cover, which is disposed on the first pole and covers the notch of the first groove.

[0032] In the above technical solution, the provision of the slot cover facilitates the electrical connection between adjacent battery cells within the battery. Furthermore, because the location where the battery cells are electrically connected is separated from the location where the conductive portion is electrically connected to the first terminal by the first groove, interference between the two is minimized, further improving the stability and reliability of the battery cells. Furthermore, the slot cover prevents foreign matter from entering the first groove, reducing interference with the battery cell assembly and further improving the reliability and stability of the battery cells.

[0033] In some embodiments, the accommodating portion has a second accommodating groove, the surface of the first pole away from the active material coating portion is the outer end face of the pole, the notch of the second accommodating groove is formed on the outer end face of the pole, the second accommodating groove is connected to the interior of the shell through the first through-hole, the conductive portion is passed through the first through-hole and is at least partially accommodated in the second accommodating groove.

[0034] In the above technical solution, on the one hand, the first electrode is provided with a second 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 second receiving groove is formed on the outer end face of the electrode, and the outer end face of the electrode is the surface of the first electrode away from the active material coating part, the second receiving groove can be open in the direction away from the active material coating part. In this way, when at least part of the conductive part is accommodated in the second receiving groove, the conductive part can be easily stored and sorted through the notch of the second receiving groove, or the conductive part can be electrically connected to the first electrode, etc., thereby reducing the difficulty of producing the battery cell and improving the production efficiency of the battery cell. At the same time, since the second receiving tank can be connected to 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 electrolyte will be consumed during the charging and discharging process of the battery cell, 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 shell through the first perforation, the second receiving tank can also serve as a receiving and buffer structure for gas production inside the electrode assembly, reducing the expansion of the battery cell and improving the reliability and stability of the battery cell.

[0035] In some embodiments, the second receiving tank has a second sinking groove, and the position where the conductive portion is electrically connected to the first pole is at least partially located in the second sinking groove.

[0036] In the above technical solution, by providing the second receiving groove with a second sink groove, the second sink groove can be used to achieve pre-positioning of the conductive part, which is beneficial for finding the correct position to achieve electrical connection and improve production efficiency.

[0037] In some embodiments, the housing assembly further includes a first cover plate, the first cover plate cooperates with the first pole and closes the notch of the second receiving groove, and the first cover plate is electrically connected to the first pole.

[0038] In the above technical solution, by providing a first cover plate to close the notch of the second receiving tank, the electrolyte in the shell can be prevented from leaking from the notch of the second receiving tank. Moreover, since the first cover plate closes the notch of the second receiving tank and is electrically connected to the first electrode, the first cover plate can be used to easily achieve indirect electrical connection between the first electrode and the busbar of the battery, and it is beneficial to increase the connection area of ​​the electrical connection, thereby helping to reduce the resistance of the electrical connection.

[0039] In some embodiments, the housing assembly further includes a second cover plate, which covers the first through-hole and the conductive portion located in the second receiving groove.

[0040] In the above technical solution, when the electrolyte enters the second containing tank from the first through-hole, the second cover plate can improve the problem of the electrolyte overflowing from the first pole, thereby improving the reliability of the battery cell.

[0041] In some embodiments, the battery cell further includes: a bracket located inside the shell and located 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.

[0042] In the above technical solution, by setting an avoidance hole on the bracket, the conductive part can be guided and constrained to pass through the avoidance hole to cooperate with the first pole. This not only simplifies the arrangement of the conductive part, saves the material of the conductive part, and reduces the cost, but also supports and guides the conductive part to cooperate with the first pole through 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.

[0043] In some embodiments, 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 accommodating portion.

[0044] In the above technical solution, since the bracket has a guide portion that at least partially extends into the accommodating portion, and at least a portion of the avoidance hole is formed by the guide portion, at least a portion of the conductive portion can be easily received in the 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 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.

[0045] In some embodiments, the avoidance hole includes a first hole segment and a second hole segment, the second hole segment is located on the 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 along the 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 connect 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 part of the first gathering portion is accommodated in the second hole segment, and the second gathering portion passes through the first hole segment.

[0046] 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 fit 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.

[0047] In some embodiments, the bracket is an integrated structure; or, the bracket is a split structure and includes a detachable first bracket and a detachable second bracket, and an avoidance hole is defined between the first bracket and the second bracket.

[0048] In the above technical solution, when the bracket is an integrated structure, the bracket is easy to process, has good reliability, and facilitates assembly of the bracket with the housing assembly, improving assembly efficiency and mating stability. When the bracket is a split structure, the first bracket and the second bracket cooperate to define an escape hole. When assembling the bracket with the battery cell assembly, there is no need to pass the conductive part from one end of the escape hole to the other. Instead, the first bracket and the second bracket can be spliced ​​together at the location of the conductive part to clamp the conductive part, so that the escape hole surrounds the conductive part, thereby facilitating assembly of the bracket with the battery cell assembly and improving assembly efficiency.

[0049] In some embodiments, the battery cell further includes: an inner insulating member, which is located inside the shell and wrapped around the active material coating portion, and is connected to the bracket.

[0050] In the above technical solution, on the one hand, by wrapping the inner insulating part outside the active material coating part, the insulation reliability between the active material coating part and the shell can be improved, the corrosion of the shell caused by the contact between the active material coating part and the shell can be reduced or prevented, and the leakage of electrolyte caused by shell corrosion can be reduced, thereby improving the reliability of the battery cell; on the other hand, connecting the inner insulating part to the bracket can reduce the difficulty of fixing the inner insulating part and improve the reliability of the inner insulating part wrapped outside the active material coating part.

[0051] In some embodiments, the housing assembly includes a plurality of poles, at least one of which is a first pole.

[0052] In the above technical solution, at least one of all the poles of the shell assembly is a first pole, so that a part of the entire battery cell can be a first pole with a receiving portion, or all of it can be a first pole with a receiving portion, so that it can be flexibly selected and matched according to actual needs such as energy density and cost to improve the applicability of the battery cell.

[0053] In some embodiments, the housing has a pressure relief portion, and the pressure relief portion and the first pole are located on the same side surface of the housing; or, the pressure relief portion and the first pole are located on two surfaces on different sides of the housing.

[0054] In the above technical solution, when the pole and the pressure relief part are arranged on the same side, processing and assembly are facilitated; and when the pole and the pressure relief part are arranged on different sides, space can be saved, the volume of the pole can be increased, and the adverse effects of the pressure relief part on the pole when releasing pressure can be reduced.

[0055] In some embodiments, the shell has a pressure relief portion, and the shell includes a shell body and a shell cover. One end of the shell body is open, the shell cover is arranged at the open end of the shell body, and the pressure relief portion is arranged on the shell cover.

[0056] In the above technical solution, the pressure relief part is easy to process and has good pressure relief reliability.

[0057] In some embodiments, along a direction perpendicular to the projection plane, a ratio of a projection area of ​​the welding portion on the projection plane to a projection area of ​​the first wall on the projection plane is in a range of 0.1% to 1%.

[0058] In the above technical solution, by setting the ratio of the projected area of ​​the welding portion between the conductive part and the first polarity pole on the projected surface to the projected area of ​​the first wall on the projected surface within the range of 0.1% to 1%, the equivalent resistance between the conductive part and the first pole can be reduced to a certain extent, thereby increasing the flow area of ​​the first pole and improving the flow capacity of the first pole, thereby facilitating the improvement of the charging speed of the battery cell and the improvement of the fast charging performance of the battery cell.

[0059] In some embodiments, the projected area of ​​the second welding surface on the projection surface is greater than or equal to 3% of the total area of ​​the projected area of ​​the first wall on the projection surface; and / or, the projected area of ​​the first welding surface on the projection surface is greater than or equal to 25% of the total area of ​​the projected area of ​​the first wall on the projection surface.

[0060] In the above technical solution, by setting the ratio of the projected area of ​​the second welding surface on the projection surface and the projected area of ​​the first welding surface on the projection surface to the projected area of ​​the first wall on the projection surface, the volume of the first pole is further increased, thereby increasing the flow area of ​​the conductive part, the first pole and the bus assembly, and further improving the charging speed of the battery cell.

[0061] In some embodiments, at least two first poles are provided on the first wall.

[0062] In the above technical solution, by arranging at least two first poles on the first wall, when the polarities of the two first poles are opposite, it is convenient for the power supply connection of the battery cell; and when the polarities of the two first poles are the same, it is convenient for the battery cell assembly to be welded and fixed to the first poles.

[0063] In some embodiments, the housing has two first walls that are opposite to each other, and a first pole is disposed on each first wall.

[0064] In the above technical solution, by arranging a first pole on each of the two first walls that are arranged opposite to each other, the two first poles can be arranged with a suitable spacing, and the power supply connection of the battery cell can be simplified.

[0065] In some embodiments, the mounting hole includes a plurality of sub-holes arranged at intervals, the first pole includes a plurality of sub-poles of the same polarity, and the plurality of sub-poles are arranged in a one-to-one correspondence in the plurality of sub-holes; the battery cell assembly includes a plurality of active material coating portions, the conductive portion includes a plurality of conductive divisions connected to the plurality of active material coating portions in a one-to-one correspondence, and each conductive division is electrically connected to a pole through a welding division; taking the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, the ratio of the sum of the projection areas of the plurality of welding divisions on the projection surface to the projection area of ​​the first wall on the projection surface is between 0.1% and 1%.

[0066] In the above technical solution, when the first pole includes multiple sub-poles of the same polarity and the welding portion includes multiple welding sub-parts, the ratio of the sum of the projected areas of the multiple welding sub-parts on the projection surface to the projected area of ​​the first wall on the projection surface is between 0.1% and 1%. This can also reduce the equivalent resistance between the conductive portion and the first pole to a certain extent, increase the flow area of ​​the first pole, and improve the flow capacity of the first pole, thereby facilitating the improvement of the charging speed of the battery cell and the fast charging performance of the battery cell.

[0067] In some embodiments, an outer contour of a projection of the first pole on the projection plane is formed by a straight line, or by a straight line and an arc.

[0068] In the above technical solution, by setting the outer contour of the projection of the first pole on the projection surface to be at least partially composed of straight lines, the part of the first pole corresponding to the straight line is subjected to less pulling than the curved part, and is less likely to crack after the first pole is installed. The strength of the first pole can be ensured, and the reliability and stability of the first pole can be improved, thereby further improving the reliability and stability of the battery cell.

[0069] In some embodiments, the dimension of the first pole in the first direction is greater than or equal to the dimension of the first pole in the second direction, and the first direction, the second direction and the axial direction of the mounting hole are perpendicular to each other.

[0070] In the above technical solution, by setting the size of the first pole in the first direction to be larger than the size of the first pole in the second direction, the first pole is formed into a long strip, which is beneficial to increase the length of the first pole and the shell, improve the installation reliability of the first pole, and enhance the stability and reliability of the battery cell; by setting the size of the first pole in the first direction to be equal to the size of the first pole in the second direction, so that under the premise of reliable installation of the first pole, a certain space is freed up for the arrangement of other components (such as other first poles, etc.).

[0071] In some embodiments, the size of the first pole in the first direction is greater than or equal to three times the size of the first pole in the second direction; and / or, the first direction is the length direction of the first wall, and the second direction is the width direction of the first wall; and / or, the size of the first wall in the first direction is greater than the size of the first wall in the second direction.

[0072] In the above technical solution, by setting the dimension of the first terminal in the first direction to be greater than or equal to three times the dimension of the first terminal in the second direction, it is applicable to situations where the first wall is longer in the first direction. The dimension of the first wall, that is, the area provided by the first wall for arranging the first terminal, is fully utilized, thereby increasing the area where the first terminal fits with the housing, improving the installation strength of the first terminal, and further improving the stability and reliability of the battery cell. By setting the first direction as the length direction of the first wall and the second direction as the width direction of the first wall, the length direction of the first wall can be consistent with the length direction of the cross section of the first terminal, and the width direction of the first wall can be consistent with the width direction of the cross section of the first terminal, effectively achieving good matching between the first wall and the first terminal on the first wall in both the first and second directions, allowing the first terminal on the first wall to further fully utilize the arrangement area provided by the first wall, thereby increasing the area where the first terminal fits with the housing, improving the installation strength of the first terminal, and thus improving the reliability and stability of the battery cell.

[0073] In a second aspect, an embodiment of the present application further provides a battery comprising the above-mentioned battery cell.

[0074] In the above technical solution, since the battery is provided with the above-mentioned battery cell, and the surface where the cross section of the mounting hole is located is taken as the projection surface, along the direction perpendicular to the projection surface, the outer contour of the projection of the second welding surface of the conductive part on the projection surface is located within the range of the outer contour of the projection of the first welding surface of the first pole on the projection surface, the reliability and stability of the battery cell can be improved, thereby improving the reliability and stability of the battery.

[0075] In a third aspect, an embodiment of the present application further provides an electrical device comprising the above-mentioned battery.

[0076] In the above technical solution, since the electric device is provided with the above-mentioned battery, and the stability and reliability of the battery can be improved, the working stability and reliability of the electric device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0078] FIG1 is a schematic diagram of an electrical device provided in some embodiments of the present application;

[0079] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0080] FIG3 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0081] FIG4 is a schematic diagram of the battery cell shown in FIG3 ;

[0082] FIG5 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0083] FIG6 is a partial schematic diagram of the battery cell shown in FIG5 ;

[0084] FIG7 is another schematic diagram of the battery cell shown in FIG5 ;

[0085] FIG8 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0086] FIG9 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0087] FIG10 is a schematic diagram of the first pole and the first wall shown in FIG9 ;

[0088] FIG11 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0089] FIG12 is a schematic diagram of the first pole and the first wall shown in FIG11;

[0090] FIG13 is a schematic diagram of the assembly of a battery cell provided in some embodiments of the present application;

[0091] FIG14 is a schematic diagram of the first pole and the first wall shown in FIG13;

[0092] FIG15 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0093] FIG16 is a schematic diagram of a battery cell provided in some embodiments of the present application;

[0094] FIG17 is a cross-sectional view taken along line VV in FIG16;

[0095] FIG18 is a schematic diagram of the assembly of a first pole and a first wall provided by some embodiments of the present application;

[0096] FIG19 is another schematic diagram of the assembly of the first pole and the first wall shown in FIG18 ;

[0097] FIG20 is a schematic diagram of welding a first pole and a conductive portion provided by some embodiments of the present application;

[0098] FIG21 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0099] FIG22 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0100] FIG23 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0101] FIG24 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0102] FIG25 is an orthographic view of the battery cell shown in FIG3 ;

[0103] FIG26 is a cross-sectional view along line AA in FIG25;

[0104] FIG27 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0105] FIG28 is an assembly diagram of a second electrode without a receiving portion, a cell assembly, and a housing according to some embodiments of the present application;

[0106] FIG29 is a partial cross-sectional schematic diagram of a battery cell provided by some embodiments of the present application;

[0107] FIG30 is a partial cross-sectional schematic diagram of a battery cell assembly provided in some embodiments of the present application;

[0108] FIG31 is a diagram illustrating various tab folding schemes for battery cell assemblies provided in some embodiments of the present application;

[0109] FIG32 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0110] FIG33 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0111] FIG34 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0112] FIG35 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0113] FIG36 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0114] FIG37 is a partial enlarged view of the W portion of FIG3 ;

[0115] FIG38 is an orthographic projection view of various first poles provided in some embodiments of the present application;

[0116] FIG39 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0117] FIG40 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0118] FIG41 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0119] FIG42 is an exploded view of the structure of a battery cell provided by some embodiments of the present application;

[0120] FIG43 is a partial cross-sectional schematic diagram of a housing assembly provided in some embodiments of the present application;

[0121] FIG44 is an exploded view of the structure of the housing assembly shown in FIG43;

[0122] FIG45 is an exploded view of the structure of the first cover plate shown in FIG44 ;

[0123] FIG46 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0124] FIG47 is an exploded view of the structure of the battery cell shown in FIG46;

[0125] FIG48 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0126] FIG49 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0127] FIG50 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0128] FIG51 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0129] FIG52 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application;

[0130] FIG53 is a schematic diagram of the coordination between a battery cell assembly and a bracket provided in some embodiments of the present application;

[0131] FIG54 is a cross-sectional view taken along line CC in FIG53;

[0132] FIG55 is a schematic structural diagram of an integrated bracket provided in some embodiments of the present application;

[0133] FIG56 is a schematic structural diagram of a split bracket provided in some embodiments of the present application;

[0134] FIG57 is a partial cross-sectional schematic diagram of a battery cell assembly and a bracket provided in some embodiments of the present application;

[0135] FIG58 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;

[0136] FIG59 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;

[0137] FIG60 is an assembly diagram of the first pole, housing, and sealing gasket shown in FIG59;

[0138] FIG61 is a schematic structural diagram of a first pole provided in some embodiments of the present application;

[0139] FIG62 is a schematic cross-sectional view of a housing assembly provided in some embodiments of the present application;

[0140] FIG63 is a schematic cross-sectional view of a housing assembly provided in some embodiments of the present application;

[0141] FIG64 is an orthographic view of a battery cell provided by some embodiments of the present application;

[0142] FIG65 is a cross-sectional view taken along line EE in FIG64;

[0143] FIG66 is a partial cross-sectional schematic diagram of a battery cell provided by some embodiments of the present application;

[0144] FIG67 is an orthographic view of a battery cell provided by some embodiments of the present application;

[0145] FIG68 is a cross-sectional view taken along line UU in FIG67;

[0146] FIG69 is an enlarged view of the circled V portion in FIG68;

[0147] FIG70 is a schematic structural diagram of a housing cover provided in some embodiments of the present application;

[0148] FIG71 is a schematic diagram of a battery cell provided in one embodiment of the present application;

[0149] Figure 72 is a schematic diagram of the connection between the outer insulating member and the patch shown in Figure 71.

[0150] Reference numerals:

[0151] Power device 1000; battery 100; controller 200; motor 300;

[0152] First direction X; second direction Y; third direction Z;

[0153] Battery cell 10; housing 20; first housing portion 201; second housing portion 202;

[0154] Housing assembly 1;

[0155] Housing 11; first wall 110; second wall 11b; housing 111; housing cover 112; mounting hole 113; sub-hole 1131;

[0156] First pole 12; first welding surface 120; first portion 120a; second portion 102b;

[0157] Pole body 12a; first limiting platform 12b; second limiting platform 12c;

[0158] Accommodation portion 121;

[0159] First receiving groove 12110; first end wall 12111; first sink 12112; first side wall 12113;

[0160] Second receiving groove 12120; second end wall 12121; second sinking groove 12122; second side wall 12123;

[0161] First groove section 12124; second groove section 12125; guide slope 12126; step surface 12127;

[0162] first perforation 12130;

[0163] Third receiving groove 12140; fourth receiving groove 12150; second through hole 12160; third through hole 12170;

[0164] Pole inner end surface 122; Pole outer end surface 123;

[0165] First pole portion 124; second pole portion 125;

[0166] First groove 126; spacer 127;

[0167] Stop portion 1281; penetration portion 1282; flange portion 1283;

[0168] Part 1, 1291; Part 2, 1292;

[0169] First cover plate 13; first conductive member 131; second groove 1311; second conductive member 132; stress relief groove 133;

[0170] Second cover plate 14; second pole 15; pressure relief portion 16; injection hole 17; avoidance groove 18;

[0171] Battery cell assembly 2; electrode assembly 2a;

[0172] Active material coating portion 21; current collector 211; active material layer 212;

[0173] Conductive portion 22; second welding surface 220; conductive sub-portion 22A;

[0174] The pole ear portion 221; the pole ear piece 2211; the first gathered portion 2212; the second gathered portion 2213; the adapter piece 222;

[0175] Bracket 3; avoidance hole 31; first hole section 311; second hole section 312; guide portion 32; first bracket 33; second bracket 34; shell guide surface 35; body portion 36; extension portion 37;

[0176] Inner insulating member 4; first sealing member 6;

[0177] Outer insulating member 5; connecting portion 51; covering portion 52; patch 5A; slot cover 7; insulating sealing component 8; insulating member 81; second sealing member 82; welding portion 9; welding sub-portion 91. DETAILED DESCRIPTION

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] The term "plurality" used in this application refers to two or more (including two).

[0184] In this application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, 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.

[0185] The battery mentioned 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 mentioned in this application can be a battery module or a battery pack. When the battery is a battery module, the battery module is composed of multiple battery cells. When the battery is a battery pack, the battery pack can be directly composed of a box and multiple battery cells disposed in the box, or the battery module can be first composed of battery cells and then the battery module is disposed in the box.

[0186] Specifically, a battery cell typically includes a housing, a cell assembly, and an electrolyte. The housing is used to hold 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 a separator.

[0187] Among them, the positive electrode sheet can generally include 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, and the positive electrode current collector not coated with the positive electrode active material layer serves as a positive electrode tab. A plurality of positive electrode tabs are stacked together and electrically connected to the positive electrode column. For example, the plurality of stacked 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 sheet, the plurality of stacked positive electrode tabs are welded to one end of the positive electrode adapter sheet, and the other end of the positive electrode adapter sheet is welded to the positive electrode column to form an electrical connection between the positive electrode tab sheet and the positive electrode column.

[0188] 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. A plurality of negative electrode tabs are stacked together and electrically connected to the negative electrode post. Exemplarily, the plurality of negative electrode tabs stacked together can be directly welded to the negative electrode post to form an electrical connection; alternatively, the battery cell assembly can further include a negative electrode adapter sheet. The plurality of negative electrode tabs stacked together are welded to one end of the negative electrode adapter sheet, and the other end of the negative electrode adapter sheet is welded to the negative electrode post to form an electrical connection between the negative electrode tab sheet and the negative electrode post.

[0189] The material of the separator is not limited, and can be, for example, polypropylene or polyethylene. The shape of the housing is adjusted according to the type of battery cell. The type of battery cell in the embodiments of the present application is not limited. For example, when the battery cell is a prismatic battery, the housing is square, and when the battery cell is a cylindrical battery, the housing is cylindrical.

[0190] 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.

[0191] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, batteries, as the power source of electric vehicles, play an irreplaceable and important role. As core components of new energy vehicles, batteries have high requirements in terms of both energy density and reliability.

[0192] In related art, the battery cell's pole is electrically connected to the cell assembly. The area of ​​the pole used for welding to the cell assembly is the first welding area, and the area of ​​the cell assembly used for welding to the pole is the second welding area. Typically, the second welding area extends beyond the first welding area to ensure the battery cell's current capacity. However, this arrangement makes welding the pole to the cell assembly inconvenient and reduces welding reliability.

[0193] In view of this, the present application provides a battery cell, which includes a shell assembly and a cell assembly, the shell assembly including a shell and a first pole, the shell having a first wall, the first wall forming a mounting hole, the first pole being arranged in the mounting hole, the first pole including a first welding surface, the cell assembly including an active material coating portion and a conductive portion electrically connected to the active material coating portion, the active material coating portion being accommodated in the shell, the conductive portion including a second welding surface in contact with the first welding surface, a part of the second welding surface being welded to a part of the first welding surface through the welding portion; taking the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, the outer contour of the projection of the second welding surface on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface.

[0194] In the battery cell of the above structure, by setting the surface where the cross section of the mounting hole is located as the projection surface, along the direction perpendicular to the projection surface, the outer contour of the projection of the second welding surface on the projection surface is located within the range of the outer contour of the projection of the first welding surface on the projection surface, and the area of ​​the first pole that can be welded to the conductive part is larger than the area of ​​the conductive part that can be welded to the first pole, so as to realize the extra-large setting of the first pole. On the one hand, when the size of the conductive part remains unchanged, enlarging the first pole can ensure the flow area of ​​the conductive part and increase the flow area of ​​the first pole; at the same time, the extra-large setting of the first pole can make the bus assembly electrically connected to the first pole be set relatively large, so that the area of ​​the bus assembly used for electrical connection (such as welding) with the first pole can be set larger, and the flow area of ​​the bus assembly can also be increased. At the same time, the increase in the flow area of ​​the conductive part, the first pole and the bus assembly can not only reduce the resistance and improve the temperature rise during the charging and discharging process to improve the reliability of the battery cell, but also increase the current to enhance the fast charging performance of the battery cell; on the other hand, the extra-large setting of the first pole can provide a larger welding space, which can increase the welding space between the first pole and the conductive part, and increase the welding space between the first pole and the bus assembly, so that the welding reliability and stability are higher, which can further improve the reliability and stability of the battery cell.

[0195] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells disclosed in this application can be used to form the electrical device, thereby increasing the scope of application of the battery cells.

[0196] The present invention provides an electrical device that uses a battery cell as a power source. The electrical 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, and the like. 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, and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0197] The following embodiments take a vehicle as an example of an electrical device to describe in detail the housing assembly, battery cells, batteries, and electrical devices provided in the embodiments of the present application.

[0198] Please refer to Figure 1, which is a schematic structural diagram of a vehicle in which the power-consuming device 1000 provided in some embodiments of the present application is a vehicle. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and 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, and the battery 100 can be provided at the bottom, head, or tail of the vehicle. The battery 100 can be used to power the vehicle, for example, the battery 100 can be used as an operating power source for the vehicle. The vehicle may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and working power requirements of the vehicle during driving. In some embodiments of the present application, the battery 100 can not only serve as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0199] Please refer to Figure 2, which is an exploded view of the structure of the battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 20 and a battery cell 10, and the battery cell 10 is accommodated in the housing 20. The housing 20 is used to provide an assembly space for the battery cell 10, and the housing 20 can adopt a variety of structures. In some embodiments, the housing 20 can include a first housing portion 201 and a second housing portion 202, and the first housing portion 201 and the second housing portion 202 cover each other, and the first housing portion 201 and the second housing portion 202 jointly define an assembly space for accommodating the battery cell 10. The second box portion 202 can be a hollow structure with one end open, and the first box portion 201 can be a plate-like structure, with the first box portion 201 covering the open side of the second box portion 202, so that the first box portion 201 and the second box portion 202 jointly define an assembly space; alternatively, the first box portion 201 and the second box portion 202 can also be hollow structures with one end open, with the open side of the first box portion 201 covering the open side of the second box portion 202. Of course, the box 20 formed by the first box portion 201 and the second box portion 202 can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0200] In the battery 100, there are one or more battery cells 10. When there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 10. The multiple battery cells 10 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 10 can be housed within the housing 20. Of course, the battery 100 can also be a battery pack composed of multiple battery cells 10 connected in series, in parallel, or in a hybrid connection, and then the battery packs are further connected in series, in parallel, or in a hybrid connection to form an entire battery, which is then 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.

[0201] Please refer to Figures 3 and 4. Figure 3 is a schematic diagram of a battery cell 10 provided in some embodiments of the present application, and Figure 4 is another schematic diagram of the battery cell 10 shown in Figure 3. The battery cell 10 is a rectangular parallelepiped, with the length of the battery cell 10 being a first direction X, the thickness of the battery cell 10 being a second direction Y, and the height of the battery cell 10 being a third direction Z. The first direction X, the second direction Y, and the third direction Z are mutually perpendicular. However, this is not limiting. In other embodiments of the present application, the battery cell 20 may also be cylindrical, flat, or have other shapes.

[0202] Please refer to Figures 5 to 8, Figure 5 is a schematic diagram of a battery cell 10 provided in some embodiments of the present application, Figure 6 is a partial schematic diagram of the battery cell 10 shown in Figure 5, Figure 7 is another schematic diagram of the battery cell 10 shown in Figure 5, and Figure 8 is a cross-sectional view of the battery cell 10 provided in some embodiments of the present application. In the embodiments of the present application, the battery cell 10 includes a shell assembly 1 and a battery cell assembly 2.

[0203] The housing assembly 1 includes a housing 11 and a first pole 12. The housing 11 has a first wall 110. The first wall 110 is formed with a mounting hole 113. The first pole 12 is disposed in the mounting hole 113 to facilitate electrical connection between the first pole 12 and the battery cell assembly 2. The axial direction of the mounting hole 113 is the third direction Z.

[0204] Among them, the shape of the shell 11 is adjusted according to the type of the battery cell 10. The type of the battery cell 10 in the embodiments of the present application is not limited. For example, when the battery cell 10 is a square battery, the shell 11 is square. When the battery cell 10 is a cylindrical battery, the shell 11 is cylindrical. The embodiments of the present application are all described using the square shell 11 as an example.

[0205] The shell 11 is provided with a pole, which is used to electrically connect to the battery cell assembly 2 to ensure the normal charging and discharging operation of the battery cell 10. Generally, the number of poles is at least two, specifically at least one positive pole and at least one negative pole. For example, when the number of poles is two, one is a positive pole and the other is a negative pole, and the two are electrically connected to the positive and negative output positions of the battery cell assembly 2 respectively; for another example, when the number of poles is four, two of them can be positive poles and the other two can be negative poles. Among them, at least one pole among the multiple poles is a first pole 12, and the first pole 12 can serve as both a positive pole and a negative pole.

[0206] In an 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 and extraction 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 first pole 12, and is not coated with active material.

[0207] 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 the portion of the positive electrode current collector coated with the positive electrode active material layer, while the negative electrode active material coating portion includes the portion of the negative electrode current collector coated with the 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 to the positive electrode post, while the negative electrode conductive portion electrically connects the negative electrode active material coating portion to the negative electrode post.

[0208] Please refer to Figures 5 to 8 again. In the embodiment of the present application, the first pole 12 includes a first welding surface 120, and the conductive part 22 includes a second welding surface 220. The second welding surface 220 contacts the first welding surface 120, and a portion of the second welding surface 220 is welded to a portion of the first welding surface 120 through the welding portion 9 to achieve welding and fixation of the first pole 12 and the conductive part 22, and achieve electrical connection between the first pole 12 and the conductive part 2, so that the conductive part 22 is used to electrically connect the active material coating part 21 and the first pole 12.

[0209] The first welding surface 120 and the second welding surface 220 can be a plane or a curved surface, and the shapes of the first welding surface 120 and the second welding surface 220 are adapted to each other; for example, the first welding surface 120 and the second welding surface 220 are both formed as planes, and the first welding surface 120 and the second welding surface 220 are arranged in parallel (as shown in Figure 8); for another example, the first welding surface 120 and the second welding surface 220 are both formed as curved surfaces.

[0210] The first welding surface 120 and the second welding surface 220 are in contact, which can be understood as at least a portion of the first welding surface 120 is in contact with at least a portion of the second welding surface 220, so that a portion of the second welding surface 220 is welded to a portion of the first welding surface 120 through the welding portion 9. Then, taking the surface where the cross section of the mounting hole 113 is located as the projection surface Ω, along the direction perpendicular to the projection surface Ω, the outer contour of the orthographic projection of the welding portion 9 is located within the outer contour range of the projection of the second welding surface 220 on the projection surface Ω, and the outer contour of the orthographic projection of the welding portion 9 is located within the outer contour range of the projection of the first welding surface 120 on the projection surface Ω, which facilitates the welding operation of the first pole 12 and the conductive portion 22.

[0211] As shown in Figures 5-8 , with the cross-sectional plane of the mounting hole 113 as projection plane Ω, along a direction perpendicular to projection plane Ω, the outer contour of the projection of the second welding surface 220 on projection plane Ω lies within the outer contour of the projection of the first welding surface 120 on projection plane Ω. That is, along the axial direction Z of the mounting hole 113, the outer contour of the projection of the second welding surface 220 on projection plane Ω lies within the outer contour of the projection of the first welding surface 120 on projection plane Ω. The first welding surface 120 may correspond to an area on the first electrode 12 that can be welded to the conductive portion 22, and the second welding surface 220 may correspond to an area on the conductive portion 22 that can be welded to the first electrode 12.

[0212] For example, in the example of Figure 6, the outer contour of the orthographic projection of the first welding surface 120 on the projection surface Ω is roughly formed into a runway shape (the runway shape is an annular closed structure surrounded by two straight lines and two arcs, and the two straight lines are opposite and spaced apart, and the two arcs respectively connect the two ends of the two straight lines), and the outer contour of the orthographic projection of the second welding surface 220 on the projection surface Ω is roughly formed into a square, and the square area is located within the above-mentioned runway-shaped contour, and the orthographic projection of the welding portion 9 on the projection surface Ω is located within the above-mentioned square area.

[0213] In the above technical solution, the area of ​​the first pole 12 that can be welded to the conductive part 22 is larger than the area of ​​the conductive part 22 that can be welded to the first pole 12, so as to realize the super-large setting of the first pole 12. On the one hand, when the size of the conductive part 22 remains unchanged, enlarging the first pole 12 can ensure the flow area of ​​the conductive part 22 and increase the flow area of ​​the first pole 12; at the same time, the super-large setting of the first pole 12 can make the bus assembly electrically connected to the first pole 12 be set relatively large, so that the area of ​​the bus assembly used for electrical connection (for example, welding) with the first pole 12 can be set larger, and the flow area of ​​the bus assembly can also be increased. At the same time, the increase in the flow area of ​​the conductive part 22, the first pole 12 and the bus assembly can not only reduce the resistance and improve the temperature rise during the charging and discharging process to improve the reliability of the battery cell 10, but also increase the current to enhance the fast charging performance of the battery cell 10; on the other hand, the extra-large setting of the first pole 12 can provide a larger welding space, which can increase the welding space between the first pole 12 and the conductive part 22, and increase the welding space between the first pole 12 and the bus assembly, so that the welding reliability and stability are higher, so as to further improve the reliability and stability of the battery cell 10.

[0214] Optionally, the conductive portion 22 and the first pole 12 are laser welded to form the welding portion 9; but not limited thereto, for example, in other embodiments, the two may also be electrically connected via a conductive structural adhesive.

[0215] In some embodiments, referring to FIG. 6 and FIG. 8 , along a direction perpendicular to the projection plane Ω, a projection area of ​​the welding portion 9 on the projection plane Ω is greater than or equal to 0.15% of a projection area of ​​the first wall 110 on the projection plane Ω.

[0216] In the above technical solution, the orthographic projection area of ​​the welding portion 9 on the projection surface Ω 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 Ω, so as to further increase the effective flow area between the conductive portion 22 and the first pole 12, thereby facilitating the improvement of the fast charging performance of the battery cell 10.

[0217] In some embodiments, referring to FIG6 and FIG8, the projection area of ​​the welding portion 9 on the projection surface is greater than or equal to 5mm 2 For example, the projection area of ​​the welding portion 9 on the projection surface can be 5mm 2 , 6mm 2 , 8mm 2 , 9mm 2 , or 10mm 2 etc.

[0218] In the above technical solution, the projection area of ​​the welding portion 9 on the projection surface is set 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.

[0219] For example, in the example of FIG6 , the projection of the welding portion 9 on the projection surface Ω extends into a long strip ( FIG20 is a schematic diagram of welding the first pole and the conductive portion provided in some embodiments of the present application, and the corresponding weld is a spiral long strip as shown in FIG20 ). Taking the projection of the welding portion 9 on the projection surface Ω extending along a straight line as an example, the length of the projection of the welding portion 9 on the projection surface Ω is greater than or equal to 10 mm, and the width of the projection of the welding portion 9 on the projection surface Ω is greater than or equal to 5 mm; of course, the projection of the welding portion 9 on the projection surface Ω can also extend along a curve (including but not limited to this smooth curve, broken line), for example, the projection of the welding portion 9 on the projection surface Ω extends into a closed ring (such as a circular ring, a polygonal ring, etc.). In addition, the shape of the projection of the welding portion 9 on the projection surface Ω can also be a solid circle.

[0220] Furthermore, the projection area of ​​the welding portion 9 on the projection surface Ω is greater than or equal to 7 mm 2 For example, the projection area of ​​the welding portion 9 on the projection surface Ω can be 7mm 2 , 7.8mm 2 , 9.5mm 2 , or 11mm 2 etc.

[0221] For example, taking the projection of the welding portion 9 on the projection plane Ω as a solid circle as an example, the diameter of the circle corresponding to the projection of the welding portion 9 on the projection plane Ω is greater than or equal to 3 mm.

[0222] In some embodiments, referring to Figures 6 and 8, along the direction perpendicular to the projection plane Ω, the projected area of ​​the welding portion 9 on the projection plane Ω is greater than or equal to 20% of the projected area of ​​the second welding surface 220 on the projection plane Ω, then the projected area of ​​the welding portion 9 on the projection plane Ω has a suitable proportion, so as to facilitate the welding operation between the conductive portion 22 and the first pole 12 while appropriately improving the current carrying capacity and heat diffusion capacity of the first pole 12.

[0223] For example, the orthographic projection area of ​​the welding portion 9 on the projection plane Ω is 20%, 25%, 35%, 40%, 50%, or 60% of the projection area of ​​the second welding surface 220 on the projection plane Ω, etc.

[0224] In some embodiments of the present application, please refer to FIG. 8 again. The first pole 12 includes a pole body 12a, a first limiting platform 12b, and a second limiting platform 12c. The pole body 12a is provided through the mounting hole 113. The first limiting platform 12b and the second limiting platform 12c are provided at both ends of the pole body 12a along a direction perpendicular to the projection plane Ω. The first limiting platform 12b is limitedly engaged with the outer side of the housing 11, and the second limiting platform 12c is limitedly engaged with the inner side of the housing 11, so that the first pole 12 is riveted to the housing 11. The direction perpendicular to the projection plane Ω can be understood as the axial direction of the mounting hole 113, that is, the third direction Z. The second limiting platform 12c is close to the end face of the battery cell assembly 2 to form a first welding surface 120.

[0225] 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 and the second limiting platform 12c can limit the movement of the first pole 12 relative to the housing 11 along the axial direction (third direction Z) of the mounting hole 113, thereby making it easy for the first pole 12 to be reliably mounted at the mounting hole 113 through the first limiting platform 12b and the second limiting platform 12c, thereby achieving a fixed connection between the first pole 12 and the housing 11 and facilitating the assembly of the first pole 12 and the housing 11. At the same time, by riveting the first pole 12 to the housing 11, it is easy to achieve a reliable connection between the first pole 12 and the housing 11 without adopting other connection methods, which is conducive to simplifying the structure of the housing assembly 1 and simplifying the assembly process of the housing assembly 1.

[0226] In addition, in the above technical solution, the end face of the second limit platform 12c close to the battery cell assembly 2 forms a first welding surface 120, which is convenient for reducing the distance between the first welding surface 120 and the battery cell assembly 2, which is beneficial for shortening the length of the conductive part 22, saving the conductive part 22 from occupying the internal space of the shell 11, and facilitating improving the volume energy density of the battery cell 10.

[0227] In some embodiments, as shown in FIG8 , the pole body 12 a , the first limiting platform 12 b and the second limiting platform 12 c are integrally formed, that is, the pole body 12 a , the first limiting platform 12 b and the second limiting platform 12 c are an integrally formed part.

[0228] In the above technical solution, since the pole body 12a, the first limit platform 12b and the second limit platform 12c are integrally formed, parts can be saved and costs can be reduced. 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, and it is not easy to crack or be damaged due to vibration or external pulling. It can improve the stability and reliability of the shell assembly 1, thereby improving the stability and reliability of the battery cell 10.

[0229] Of course, in other embodiments of the present application, at least one of the first limiting platform 12b and the second limiting platform 12c is a separate component from the pole body 12a.

[0230] In some embodiments of the present application, as shown in Figures 7 to 10, the length L5 of the pole body 12a in the first direction X is greater than or equal to 1 / 3 of the length dimension a0 of the first wall 110 in the first direction X, for example, L5 can be a0 / 3, 0.35*a0, or 0.42*a0, etc.; the width dimension L6 of the pole body 12a in the second direction Y is greater than or equal to 1 / 2 of the width dimension b0 of the first wall 110 in the second direction Y, for example, L6 can be b0 / 2, 0.55*b0, or 0.6*b0, or 0.68*b0, etc.; the ratio of the circumference of the circumference of the pole body 12a and the mounting hole 113 to the circumference of the first wall 110 is within the range of 25% to 40%, that is, the circumference of the circumference of the pole body 12a and the mounting hole 113 is greater than or equal to 25% of the circumference of the first wall 110, and less than or equal to 25% of the circumference of the first wall 110. The cross-sectional area of ​​the portion of the pole body 12a that fits the mounting hole 113 is greater than or equal to 10% of the area of ​​the first wall 110. For example, the cross-sectional area of ​​the portion of the pole body 12a that fits the mounting hole 113 may be 10%, 10.6%, 11%, 11.5%, or 12% of the area of ​​the first wall 110. In the axial direction Z of the mounting hole 113, the ratio of the thickness dimension t of the pole body 12a to the thickness dimension t0 of the first wall 110 is greater than 1 and less than 1.5. For example, the ratio may be 1.1, 1.15, 1.2, 1.3, or 1.45. Of course, in other embodiments, only part of the above conditions may be met, and the embodiments of the present application are not limited thereto.

[0231] In the above technical solution, when at least one of the ratio of the length of the pole body 12a to the length of the first wall 110, the ratio of the width of the pole body 12a to the width of the first wall 110, and the ratio of the circumference of the pole body 12a and the mounting hole 113 to the circumference of the first wall 110 meets the above corresponding range, the pole body 12a accounts for a large proportion in the length direction and width direction of the first wall 110, and the size of the matching portion of the pole body 12a and the mounting hole 113 is large, the stability of the riveting between the first pole 12 and the first wall 110 can be improved, the riveting strength of the first pole 12 can be ensured, and the battery cell can be improved. The reliability and stability of the body 10; when the ratio of the cross-sectional area of ​​the pole body 12a to the area of ​​the first wall 110 is within the above range, the flow area of ​​the first pole 12 is large, which can improve the flow and fast charging capabilities of the first pole 12; when the thickness ratio of the pole body 12a to the thickness of the first wall 110 meets the above corresponding range, it is convenient for the pole body 12a to be reliably matched with the mounting hole 113, so that the first limit platform 12b and the second limit platform 12c are respectively located on the inner and outer sides of the shell 11, so as to achieve smooth riveting of the first pole 12, improve the riveting convenience and riveting reliability. At the same time, when all parameters of the pole body 12a are within the above range, the number of first poles 12 on the first wall 110 can be one or more, in particular, two, and the two first poles 12 are arranged at intervals along the second direction Y, and the polarities of the two first poles 12 can be the same or opposite; of course, the number of first poles 12 on the first wall 110 can also be four.

[0232] It can be understood that in the embodiment of the present application, the perimeter of the first wall 110 can be understood as the perimeter of the outer contour of the projection of the first wall 110 on the projection surface Ω. For example, the first wall 110 is roughly formed into a rectangular structure, and the outer contour of the projection of the first wall 110 on the projection surface Ω is also roughly a rectangular structure. The perimeter of the first wall 110 can be simply understood as (2*a0+2*b0).

[0233] Optionally, the circumferential circumference of the pole body 12a and the mounting hole 113 is greater than or equal to 26.5% of the circumference of the first wall 110, and less than or equal to 40% of the circumference of the first wall 110. For example, the circumferential circumference of the pole body 12a and the mounting hole 113 is 26.5%, 27%, 27.2%, 27.7%, or 28% of the circumference of the first wall 110, so as to further ensure the riveting matching length of the first pole 12 and the shell 11, improve the riveting reliability, and take into account the reliability of the use of the first wall 110.

[0234] Optionally, the cross-sectional area of ​​the portion where the pole body 12a cooperates with the mounting hole 113 is greater than or equal to 11.6% of the area of ​​the first wall 110. For example, the cross-sectional area of ​​the portion where the pole body 12a cooperates with the mounting hole 113 is 11.6%, 12%, 12.4%, 12.7%, or 13.8% of the area of ​​the first wall 110, etc., so as to further ensure the riveting cooperation area between the first pole 12 and the housing 11 and improve the riveting reliability.

[0235] Optionally, the length dimension L5 of the pole body 12a in the first direction X is greater than or equal to 40 mm, for example, L5 can be 40 mm, 43 mm, 46 mm, 50 mm, or 52 mm; the width dimension L6 of the pole body 12a in the second direction Y is greater than or equal to 15 mm, for example, L5 can be 15 mm, 15.5 mm, 16 mm, 16.2 mm, or 17 mm; and / or the cross-sectional area of ​​the portion of the pole body 12a that cooperates with the mounting hole 113 is greater than or equal to 600 mm 2 For example, the cross-sectional area of ​​the portion where the pole body 12a fits in the mounting hole 113 is 600 mm. 2 , 630mm 2 、680mm 2 , or 700mm 2 wait.

[0236] For example, FIG9 is a schematic diagram of a battery cell provided in some embodiments of the present application; FIG10 is a schematic diagram of the first pole and the first wall shown in FIG9; FIG11 is a schematic diagram of the battery cell provided in some embodiments of the present application; and FIG12 is a schematic diagram of the first pole and the first wall shown in FIG11. Referring to FIG7 to FIG12, in an embodiment of the present application, two mounting holes 113 are formed on the first wall 110, and each mounting hole 113 is respectively provided with a first pole 12, and the polarities of the two first poles 12 are opposite; wherein each first pole 12 satisfies at least one of the following conditions: the length L5 of the pole body 12a in the first direction X is greater than or equal to 1 / 3 of the length dimension a0 of the first wall 110 in the first direction X; the width dimension L6 of the pole body 12a in the second direction Y is greater than or equal to the width dimension L7 of the first wall 110. 10 is 1 / 2 of the width dimension b0 in the second direction Y; the circumference of the circumference of the pole body 12a that cooperates with the mounting hole 113 is greater than or equal to 25% of the circumference of the first wall 110; the cross-sectional area of ​​the portion of the pole body 12a that cooperates with the mounting hole 113 is greater than or equal to 10% of the area of ​​the first wall 110; along the axial direction Z of the mounting hole 113, the thickness dimension t of the pole body 12a is greater than or equal to 0.6 of the thickness dimension t0 of the first wall 110, and t is less than or equal to 1.5 of the thickness dimension t0 of the first wall 110.

[0237] In some embodiments of the present application, as shown in Figures 7 to 10, the ratio of the length dimension L1 of the first limiting platform 12b in the first direction X to the length dimension a0 of the first wall 110 in the first direction X is in the range of 1 / 3 to 1 / 2, that is, a0 / 3≤L1≤a0 / 2, for example, L1 can be a0 / 3, 0.34*a0, 0.36*a0, 0.39*a0, 0.4*a0, 0.42*a0, 0.45*a0, 0.47*a0, 0.49*a0, or 0.5*a0, etc.; the width dimension of the first limiting platform 12b in the second direction Y is The ratio of L2 to the width dimension b0 of the first wall 110 in the second direction Y is within the range of 1 / 2 to 3 / 4, that is, b0 / 2≤L2≤3*b0 / 4, for example, L2 can be 0.5*b0, 0.52*b0, 0.54*b0, 0.55*b0, 0.58*b0, 0.6*b0, 0.62*b0, 0.65*b0, 0.7*b0, 0.75*b0, etc. The first limiting platform 12b is columnar, and the ratio of the circumference dimension of the outer periphery of the first limiting platform 12b to the circumference dimension of the first wall 110 is within the range of 30% to 50%, that is, the first limiting platform 12b is cylindrical ... The circumference of the outer periphery of the limiting platform 12b is greater than or equal to 30% of the circumference of the first wall 110 and less than or equal to 50% of the circumference of the first wall 110. For example, the circumference of the outer periphery of the first limiting platform 12b is 30%, 35%, 38%, 40%, 42%, 46%, 48%, or 50% of the circumference of the first wall 110; the ratio of the cross-sectional area S1 of the first limiting platform 12b to the area of ​​the first wall 110 is within the range of 9% to 25%, that is, 9%*S0≤S1≤25%*S0, and the cross section of the first limiting platform 12b is equal to the axis of the mounting hole 113. Perpendicular to the direction Z, for example, the cross-sectional area S1 of the first limiting platform 12b is the area S0 of the first wall 110, for example, S1 can be 9.4%*S0, 10.4%*S0, 13.6%*S0, 15.2%*S0, 18%*S0, 21%*S0, 22%*S0, 23.2%*S0, 24%*S0, or 25%*S0, etc.; along the axial direction Z of the mounting hole 113, the ratio of the thickness dimension t1 of the first limiting platform 12b to the thickness dimension t0 of the first wall 110 is within the range of 0.6 to 1.5, that is, 0.6≤t1 / t0≤1.5. Of course, in other embodiments, the above multiple conditions may only meet some of the conditions, and the embodiments of the present application are not limited thereto.

[0238] In the above technical solution, when at least one of the ratio of the length of the first limiting platform 12b to the length of the first wall 110, the ratio of the width of the first limiting platform 12b to the width of the first wall 110, and the ratio of the circumference of the first limiting platform 12b to the circumference of the first wall 110 meets the above corresponding range, the first limiting platform 12b accounts for a large proportion in the length direction and the width direction of the first wall 110, and the size of the matching part of the first limiting platform 12b and the mounting hole 113 is large, which can improve the stability of the riveting between the first pole 12 and the first wall 110, ensure the riveting strength of the first pole 12, thereby improving the reliability and Stability; When the ratio of the cross-sectional area of ​​the first limiting platform 12b to the area of ​​the first wall 110 is within the above range, the flow area of ​​the first pole 12 is large, which can improve the flow and fast charging capabilities of the first pole 12; When the ratio of the thickness of the first limiting platform 12b to the thickness of the first wall 110 meets the above corresponding range, it is convenient to prevent the first pole 12 from being easily separated from the first wall 110, further improving the riveting reliability, and helping to reduce the thickness of the portion of the first limiting platform 12b protruding outside the shell 11, reducing the space occupied by the first pole 12 outside the shell 11, which is conducive to improving the volume energy density of the battery 100. At the same time, when all parameters of the first limiting platform 12b are within the above range, the number of first poles 12 of the same polarity on the first wall 110 can be one or more, in particular, two, and the two first poles 12 are arranged at intervals along the second direction Y. Of course, the number of first poles 12 of the same polarity can also be four.

[0239] In the above technical solution, the first limit platform 12b is columnar, which may refer to the first limit platform 12b being a solid columnar shape or the first limit platform 12b being a hollow columnar shape. At this time, the first limit platform 12b is formed with a through hole passing through the first limit platform 12b along the axial direction Z of the mounting hole 113 (for example, the accommodating portion 121 described later is formed on the first limit platform 12b), which is beneficial to reducing the weight of the first pole 12.

[0240] In the above technical solution, by setting a0 / 3≤L1≤a0 / 2, the reliability of the first wall 110 and the matching of the number of poles 12 required to be arranged on the first wall 110 are taken into consideration while improving the riveting stability between the first pole 12 and the housing 11.

[0241] In the above technical solution, by setting b0 / 2≤L2≤3*b0 / 4, it is also convenient to take into account the reliability of the first wall 110 and the matching of the number of poles 12 required to be arranged on the first wall 110 while improving the riveting stability between the first pole 12 and the shell 11.

[0242] In the above technical solution, the first limiting platform 12b is provided in a columnar shape, and the ratio of the circumference of the outer periphery of the first limiting platform 12b to the circumference of the first wall 110 is within the range of 30% to 50%. This is so as to improve the reliability of the riveting between the first pole 12 and the shell 11 while taking into account the reliability of the use of the first wall 110 and the matching of the number of poles 12 required to be arranged on the first wall 110.

[0243] In the above technical solution, by setting 9%*S0≤S1≤25%*S0, the reliability of the first wall 110 is taken into consideration while the reliability of the riveting between the first pole 12 and the housing 11 is improved.

[0244] 7 , 9 and 10 , two mounting holes 113 are formed on the first wall 110, and each mounting hole 113 is respectively provided with a first pole 12, and the polarities of the two first poles 12 are opposite; wherein, each first pole 12 satisfies at least one of the following conditions: the length dimension L1 of the first limit platform 12b in the first direction X is greater than or equal to 1 / 3 of the length dimension a0 of the first wall 110 in the first direction X; the width dimension L2 of the first limit platform 12b in the second direction Y is greater than or equal to 1 / 2 of the width dimension b0 of the first wall 110 in the second direction Y; the first limit platform 12b is columnar, and the circumference dimension of the outer periphery of the first limit platform 12b is greater than or equal to 30% of the circumference dimension of the first wall 110; the cross-sectional area S1 of the first limit platform 12b is greater than or equal to 9% of the area S0 of the first wall 110; along the axial direction Z of the mounting hole 113, the thickness dimension t1 of the first limit platform 12b is greater than or equal to the thickness dimension t2 of the first wall 110 0.6 of the thickness dimension t0 of the first wall 110, and t1 is less than or equal to 1.5 of the thickness dimension t0 of the first wall 110.

[0245] In some embodiments of the present application, as shown in Figures 7 to 10, the ratio of the length dimension L3 of the second limiting platform 12c in the first direction X to the dimension a0 of the first wall 110 in the first direction X is in the range of 1 / 3 to 1 / 2, that is, a0 / 3≤L3≤a0 / 2, for example, the length dimension L3 of the second limiting platform 12c in the first direction X is a0 / 3, 0.35*a0, 0.4*a0, 0.42*a0, 0.47*a0, or 0.5*a0, etc.; the width dimension L4 of the second limiting platform 12c in the second direction Y is the same as the width dimension L5 of the first wall 110 in the second direction Y. The ratio of the width dimension b0 on the second limit platform 12c is within the range of 1 / 2 to 3 / 4, that is, b0 / 2≤L4≤3*b0 / 4. For example, the width dimension L4 of the second limit platform 12c in the second direction Y is b0 / 2, 0.52*b0, 0.55*b0, 0.58*b0, 0.6*b0, 0.62*b0, 0.67*b0, 0.7*b0, etc. The second limit platform 12c is columnar, and the ratio of the circumference dimension of the outer periphery of the second limit platform 12c to the circumference dimension of the first wall 110 is within the range of 30% to 50%, that is, the circumference dimension of the outer periphery of the second limit platform 12c is less than 1%. The perimeter of the second limiting platform 12c is greater than or equal to 30% of the perimeter of the first wall 110 and less than or equal to 50% of the perimeter of the first wall 110. For example, the perimeter of the outer perimeter of the second limiting platform 12c is 30%, 32%, 35%, 38%, 40%, 42%, 45%, 47%, or 50% of the perimeter of the first wall 110. The ratio of the cross-sectional area S2 of the second limiting platform 12c to the area S0 of the first wall 110 is within a range of 9% to 25%, that is, 9%*S0≤S2≤25%*S0. For example, the cross-sectional area S2 of the second limiting platform 12c is 9%*S0, 9. 4%*S0, 9.9%*S0, 10.3%*S0, 11%*S0, 11.4%*S0, 12%*S0, 13%*S0, 14%*S0, 14.5%*S0, 15.6%*S0, 16%*S0, 17%*S0, 18.6%*S0, 19.2%*S0, 20%*S0, or 25% S0, etc.; along the axial direction Z of the mounting hole 113, the ratio of the thickness dimension t2 of the second limiting platform 12c to the thickness dimension t0 of the first wall 110 is within the range of 0.6 to 1.5, that is, 0.6≤t2 / t0≤1.5. Of course, in other embodiments, the above multiple conditions may only meet some of the conditions, and the embodiments of the present application are not limited thereto.

[0246] In the above technical solution, when at least one of the ratio of the length of the second limit platform 12c to the length of the first wall 110, the ratio of the width of the second limit platform 12c to the width of the first wall 110, and the ratio of the outer circumference of the second limit platform 12c to the circumference of the first wall 110 meets the above corresponding range, the second limit platform 12c accounts for a large proportion in the length direction and width direction of the first wall 110, and the size of the matching part of the second limit platform 12c and the mounting hole 113 is large, which can improve the stability of the riveting between the first pole 12 and the first wall 110, ensure the riveting strength of the first pole 12, and thus improve the reliability of the battery cell 10. and stability; when the ratio of the cross-sectional area of ​​the second limiting platform 12c to the area of ​​the first wall 110 is within the above range, the flow area of ​​the first pole 12 is large, which can improve the flow and fast charging capabilities of the first pole 12; when the ratio of the thickness of the second limiting platform 12c to the thickness of the first wall 110 meets the above corresponding range, it is convenient to avoid the first pole 12 from being easily separated from the first wall 110, further improving the riveting reliability, and helping to reduce the thickness of the portion of the second limiting platform 122 protruding from the shell 11, reducing the space occupied by the first pole 12 in the shell 11, which is conducive to improving the volume energy density of the battery cell 10. At the same time, when all parameters of the second limiting platform 12c are within the above range, the number of first poles 12 of the same polarity on the first wall 110 can be one or more, in particular, two, and the two first poles 12 are arranged at intervals along the second direction Y. Of course, the number of first poles 12 of the same polarity can also be four.

[0247] In the above technical solution, the second limit platform 12c is columnar, which may refer to the second limit platform 12c being a solid columnar shape or a hollow columnar shape. At this time, the second limit platform 12c is formed with a through hole passing through the first limit platform 12b along the axial direction Z of the mounting hole 113 (for example, the accommodating portion 121 described later is formed on the second limit platform 12c), which is beneficial to reducing the weight of the first pole 12.

[0248] In the above technical solution, by setting a0 / 3≤L3≤a0 / 2, the reliability of the first wall 110 and the matching of the number of poles 12 required to be arranged on the first wall 110 are taken into consideration while improving the riveting stability between the first pole 12 and the housing 11.

[0249] In the above technical solution, by setting b0 / 2≤L4≤3*b0 / 4, it is also convenient to take into account the reliability of the first wall 110 and the matching of the number of poles 12 required to be arranged on the first wall 110 while improving the riveting stability between the first pole 12 and the shell 11.

[0250] In the above technical solution, by setting 9%*S0≤S2≤25%*S0, the reliability of the first wall 110 is taken into consideration while the reliability of the riveting between the first pole 12 and the housing 11 is improved.

[0251] For example, in the examples of Figures 7, 9 and 10, two mounting holes 113 are formed on the first wall 110, and each mounting hole 113 is respectively provided with a first pole 12, and the polarities of the two first poles 12 are opposite, and each first pole 12 respectively satisfies at least one of the following conditions: the length dimension L3 of the second limiting platform 12c in the first direction X is greater than or equal to 1 / 3 of the length dimension a0 of the first wall 110 in the first direction X; the width dimension L4 of the second limiting platform 12c in the second direction Y is greater than or equal to the first wall 110 1 / 2 of the width dimension b0 in the second direction Y; the second limit platform 12c is columnar, and the circumference dimension of the outer periphery of the second limit platform 12c is greater than or equal to 30% of the circumference dimension of the first wall 110; the cross-sectional area S2 of the second limit platform 12c is greater than or equal to 9% of the area S0 of the first wall 110; along the axial direction Z of the mounting hole 113, the thickness dimension t2 of the second limit platform 12c is greater than or equal to 0.6 of the thickness dimension t0 of the first wall 110, and t2 is less than or equal to 1.5 of the thickness dimension t0 of the first wall 110.

[0252] In some embodiments, as shown in FIG8 , a portion of the first pole 12 is located inside the housing 11, and another portion of the first pole 12 is located outside the housing 11. With the cross-sectional surface of the mounting hole 113 as the projection surface, along a direction perpendicular to the projection surface Ω, the projected area of ​​the portion of the first pole 12 located outside the housing 11 on the projection surface is greater than or equal to 2% of the projected area of ​​the first wall 110 on the projection surface.

[0253] In the above technical solution, by setting the projected area of ​​the part of the first pole 12 located outside the shell 11 on the projected surface to be greater than or equal to 2% of the projected area of ​​the first wall 110 on the projected surface, it is convenient to increase the area of ​​the connectable region of the first pole 12 that can be connected to the busbar component, thereby facilitating the increase of the connection area between the first pole 12 and the busbar component, and increasing the effective flow area between the first pole 12 and the busbar component, which is beneficial to improving the charging speed of the battery cell 10.

[0254] For example, the projection area of ​​the portion of the first pole 12 outside the housing 11 on the projection plane is 2%, 3%, 4%, 5.5%, 6.8%, etc., of the projection area of ​​the first wall 110 on the projection plane.

[0255] In some embodiments, as shown in FIG8 , in the axial direction Z of the mounting hole 113 , the thickness dimension t1 of the first limiting platform 12b satisfies 2 mm ≤ t1 ≤ 3.2 mm, so as to simultaneously consider the riveting strength between the first terminal 12 and the housing 11 and the space occupied by the first terminal 12 outside the housing 11. This avoids setting the thickness of the first limiting platform 12b too large due to consideration of the riveting strength of the first terminal 12, thereby reducing the volumetric energy density of the battery cell 10, and also avoids setting the thickness of the first limiting platform 12b too small due to consideration of the volumetric energy density of the battery cell 10, thereby reducing the riveting strength of the first terminal 12 at the first limiting platform 12b. For example, t1 can be 2 mm, 2.3 mm, 2.5 mm, 2.8 mm, 3 mm, or 3.2 mm, etc.

[0256] In some embodiments, as shown in FIG8 , in the axial direction Z of the mounting hole 113 , the thickness dimension t2 of the first limiting platform 12b satisfies t2 ≤ 2 mm. This allows for both the riveting strength of the first terminal 12 and the housing 11 and the space occupied by the first terminal 12 within the housing 11 to be balanced. This avoids setting the thickness of the second limiting platform 12c too large due to consideration of the riveting strength of the first terminal 12, thereby reducing the volumetric energy density of the battery cell 10. Furthermore, it avoids setting the thickness of the second limiting platform 12c too small due to consideration of the volumetric energy density of the battery cell 10, thereby reducing the riveting strength of the first terminal 12 at the second limiting platform 12c. For example, t2 may be 2 mm, 1.8 mm, 1.7 mm, or 1.6 mm, etc.

[0257] In some embodiments, as shown in FIG8 , in the radial direction of the mounting hole 113, the width of the portion of the first limiting platform 12b extending beyond the outer peripheral wall of the pole body 12a is x, where x ≥ 1 mm, to further enhance the riveting strength between the first pole 12 and the housing 11. For example, x can be 1 mm, 1.5 mm, 1.8 mm, or 2 mm, etc.

[0258] 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.

[0259] As shown in FIG8 , in a first embodiment, the conductive portion 22 includes a plurality of tabs 2211 connected to the active material coating portion 21 . The plurality of tabs 2211 converge (i.e., gather or converge toward each other) at one end near the active material coating portion 21 to form a first converged portion 2212 . The plurality of tabs 2211 converge and connect at one end away from the active material coating portion 21 to form a second converged portion 2213 . The first converged portion 2212 connects the second converged portion 2213 and the active material coating portion 21 . The second converged portion 2213 has a second welded surface 220 formed on one end face of the second converged portion 2213 near the first electrode 12 . The second converged portion 2212 is welded to the first electrode 12 via the weld 9 .

[0260] 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.

[0261] Moreover, by providing the second welding surface 220 on the end surface of the second folded portion 2213 close to the first pole 12, it is beneficial to shorten the length of the conductive portion 22, save the space occupied by the conductive portion 22, and facilitate improving the volume energy density of the battery cell 10.

[0262] 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.

[0263] In the above technical solution, “a plurality of electrode tabs 2211 are gathered together at one end close to the active material coating portion 21 to form a first gathered portion 2212, and a plurality of electrode tabs 2211 are gathered together at one end away from the active material coating portion 21 and connected to form a second gathered portion 2213” is intended to illustrate that: along the extension direction of the electrode tab 2211, the first gathered portion 2212 and the second gathered portion 2213 are sequentially arranged along the direction away from the active material coating portion 21, and the specific positions of the first gathered portion 2212 and the second gathered portion 2213 are not limited, that is, it does not require the first gathered portion 2212 to be close to the active material coating portion 21, nor does it require the second gathered portion 2213 to be far from the active material coating portion 21.

[0264] Exemplarily, 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 pole ear sheets 2211 are structures electrically connected to the current collector 211 but not coated with active material, and can be formed by directly die-cutting the current collector 211, 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 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.

[0265] In some optional examples, the current collector 211 and the tab 2211 can be an integral part. For example, for the positive electrode, it can be an integrally formed aluminum foil. For example, for the negative electrode, it can be an integrally formed copper foil, etc.

[0266] In conjunction with Figure 8, in the first embodiment, as an optional solution, with the surface where the cross section of the mounting hole 113 is located as the projection surface Ω, along the direction perpendicular to the projection surface Ω, at least part of the outer contour of the projection of the first gathering portion 2212 on the projection surface Ω is located within the range of the outer contour of the projection of the first welding surface 120 on the projection surface Ω.

[0267] For example, in the example of Figure 8, along the direction perpendicular to the projection plane Ω, the projection of the first gathering portion 2212 on the projection plane Ω is located within the outer contour range of the projection of the first welding surface 120 on the projection plane Ω; in the example of Figure 22, along the direction perpendicular to the projection plane Ω, a part of the projection of the first gathering portion 2212 on the projection plane Ω is located within the outer contour range of the projection of the first welding surface 120 on the projection plane Ω, and another part of the projection of the first gathering portion 2212 on the projection plane Ω is located outside the outer contour range of the projection of the first welding surface 120 on the projection plane Ω.

[0268] In the above technical solution, by setting the outer contour of the projection of the first gathering portion 2212 on the projection plane Ω to be at least partially located within the outer contour range of the projection of the first welding surface 120 on the projection plane Ω, it is beneficial to save the space occupied by the first gathering portion 2212 in the axial direction of the vertical mounting hole 113, and to facilitate reducing the distance between the first pole 12 and the battery cell assembly 2 in the axial direction of the mounting hole 113, so as to improve the energy density of the battery cell 10.

[0269] In conjunction with Figure 8, in the first embodiment, as an optional solution, a portion of the end surface of one side of the second gathered portion 2213 close to the first pole 12 forms a second welding surface 220, and along the direction perpendicular to the projection plane Ω, the projected area of ​​the second welding surface 220 on the projection plane Ω is greater than or equal to 40% of the projected area of ​​the second gathered portion 2213 on the projection plane Ω, so that the second gathered portion 2213 can provide a sufficient welding area.

[0270] For example, the projection area of ​​the second welding surface 220 on the projection plane Ω is 40%, 45%, 50%, 65%, or 70% of the projection area of ​​the second gathered portion 2213 on the projection plane Ω.

[0271] FIG21 is a cross-sectional view of a battery cell provided by some embodiments of the present application. In conjunction with FIG21 , in a second embodiment, the conductive portion 22 includes a plurality of tabs 2211 connected to the active material coating portion 21 and a transition piece 222. The plurality of tabs 2211 are gathered together at one end near the active material coating portion 21 to form a first gathered portion 2212. The plurality of tabs 2211 are gathered together at one end away from the active material coating portion 21 and connected to form a second gathered portion 2213. The first gathered portion 2212 connects the second gathered portion 2213 to the active material coating portion 21, and the transition piece 222 connects the second gathered portion 2213 to the first electrode 12. The portion of the transition piece 222 near the end face of the first electrode 12 forms a second welding surface 220.

[0272] In the above technical solution, the indirect electrical connection between the second gathered portion 2213 and the first pole 12 is achieved by using the adapter plate 222. The adapter plate 222 can be welded to the first pole 12 at a position avoiding the second gathered 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, the structure of the pole tab 2211 can also be simplified by electrically connecting the first pole 12 and the pole tab 2211 through the adapter plate 222.

[0273] Exemplarily, 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 transition piece 222, the pole ear portion 221 includes a plurality of pole ear pieces 2211 electrically connected to the current collector 211, the plurality of pole ear pieces 2211 converge near the current collector 211 to form a first gathering portion 2212, the plurality of pole ear pieces 2211 converge away from the current collector 211 and are connected to form a second gathering portion 2213, and the transition piece 222 is electrically connected to the second gathering portion 2213.

[0274] FIG22 is a cross-sectional view of a battery cell provided in some embodiments of the present application. In conjunction with FIG21 and FIG22 , in a second embodiment, as an optional solution, with the cross-sectional plane of the mounting hole 113 as projection plane Ω, along a direction perpendicular to the projection plane Ω, at least a portion of the outer contour of the projection of the second gathered portion 2213 on the projection plane Ω lies within the outer contour of the projection of the first welding surface 120 on the projection plane Ω. With the cross-sectional plane of the mounting hole 113 as projection plane Ω, along a direction perpendicular to the projection plane Ω, at least a portion of the outer contour of the projection of the first gathered portion 2212 on the projection plane Ω lies within the outer contour of the projection of the first welding surface 120 on the projection plane Ω. Of course, in other embodiments, only one of the second gathered portion 2213 and the first gathered portion 2212 may meet the aforementioned configuration requirements, and this embodiment of the present application is not limiting.

[0275] In the above technical solution, by setting the outer contour of the projection of the second gathering portion 2213 on the projection plane Ω to be at least partially located within the outer contour range of the projection of the first welding surface 120 on the projection plane Ω, and the outer contour of the projection of the first gathering portion 2212 on the projection plane Ω to be at least partially located within the outer contour range of the projection of the first welding surface 120 on the projection plane Ω, it is beneficial to save the space occupied by the first gathering portion 2212 and the second gathering portion 2213 in the axial direction of the vertical mounting hole 113, and to reduce the distance between the first pole 12 and the battery cell assembly 2 in the axial direction of the mounting hole 113, so as to improve the energy density of the battery cell 10.

[0276] For example, in the example of Figure 21, the first welding surface 120 is located on the side of the first pole 12 facing the battery cell assembly 2; in the example of Figure 22, the first welding surface 120 is located on the side of the first pole 12 facing away from the battery cell assembly 2. At this time, a first through-hole 12130 can be formed on the first pole 12 to facilitate the conductive part 22 to pass through the first through-hole 12130 to the side of the first pole 12 facing away from the battery cell assembly 2 to be welded to the first welding surface 120. At this time, the first welding surface 120 may include a first part 120a and a second part 120b, and the first part 120a and the second part 120b are respectively located on opposite sides of the first through-hole 12130.

[0277] In conjunction with Figure 21, in the second embodiment, as an optional solution, the adapter plate 222 forms a second welding surface 220 on a portion of the end surface close to the first pole 12. Along the direction perpendicular to the projection plane Ω, the projected area of ​​the second welding surface 220 on the projection plane Ω is greater than or equal to 1 / 12 of the projected area of ​​the adapter plate 222 on the projection plane Ω, so that the adapter plate 222 can provide a sufficient welding area.

[0278] For example, the projection area of ​​the second welding surface 220 on the projection plane Ω is 1 / 11, 1 / 10, 1 / 9, or 1 / 8 of the projection area of ​​the adapter plate 222 on the projection plane Ω.

[0279] Optionally, the adapter plate 222 is ultrasonically welded to the second retracted portion 2213 , and the adapter plate 222 is laser welded to the first pole 12 .

[0280] In some embodiments of the present application, Figure 23 is a cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 24 is a cross-sectional view of a battery cell provided in some embodiments of the present application; Figure 25 is an orthographic projection view of the battery cell shown in Figure 3; Figure 26 is a cross-sectional view along line AA in Figure 25. As shown in Figures 23 to 26, the first pole 12 is provided with a receiving portion 121, and at least a portion of the conductive portion 22 is received in the receiving portion 121.

[0281] At least one of the multiple poles of the battery cell 10 is a first pole 12 having an accommodating portion 121. The accommodating portion 121 is a virtual structure having an accommodating space, and can be a slot-shaped structure, a hole-shaped structure, or a composite structure of a slot-shaped structure and a hole-shaped structure. In other words, all poles on the housing 11 can be first poles 12 having an accommodating portion 121, or a portion of the poles on the housing 11 can be first poles 12 having an accommodating portion 121. When a portion of the poles on the housing 11 are first poles 12 having an accommodating portion 121, the remaining poles on the housing 11 are second poles 15 without an accommodating portion 121 (Figure 27 is a schematic structural diagram of a battery cell 10 provided in some embodiments of the present application; Figure 28 is an assembly diagram of a second pole 12 without an accommodating portion 121, a cell assembly 2, and a housing 11 provided in some embodiments of the present application, see Figures 27 and 28).

[0282] Both the first electrode 12 and the second electrode 15 can be electrically connected to the active material coating portion 21 via the conductive portion 22 to enable the battery cell 10 to charge and discharge. Of course, in other embodiments of the present application, the housing assembly 1 can also be provided with only one electrode, which is the first electrode 12. The first electrode 12 includes two parts, which are insulated and connected, and can be used as the positive electrode and the negative electrode respectively. To simplify the description, the following mainly uses the example of all the electrodes on the housing 11 being the first electrode 12 formed with the accommodating portion 121.

[0283] In the above technical solution, referring to Figures 25 and 26 , at least a portion of the guide portion 22 is accommodated within the corresponding accommodating portion 121. "At least a portion" means that the conductive portion 22 can be entirely accommodated within the accommodating portion 121, or only a portion of the conductive portion 22 can be accommodated within the accommodating portion 121. Since the first terminal 12 is provided with the accommodating portion 121, the hollow structure of the accommodating portion 121 can reduce the weight of the terminal 12 to a certain extent, thereby improving the weight energy density of the battery cell 10 and the battery 100.

[0284] Furthermore, by partially or entirely containing the conductive portion 22 within the accommodating portion 121, the portion of the conductive portion 22 located within the accommodating portion 121 can occupy the space within the first electrode 12, thereby reducing the space occupied by the conductive portion 22 within the housing 11. When the size of the housing 11 is fixed, some space can be saved within the housing 11 to accommodate a larger active material coating portion 21, thereby improving the volumetric energy density of the battery cell 10. For example, when the conductive portion 22 is extended from the side of the active material coating portion 21 close to the first electrode 12, the space occupied by the conductive portion 22 between the active material coating portion 21 and the first electrode 12 can be reduced, thereby increasing the size of the active material coating portion 21 in the direction in which the conductive portion 22 is extended, reducing the distance between the active material coating portion 21 and the first electrode 12, and thus improving the energy density of the battery cell 10.

[0285] Furthermore, by accommodating at least a portion of the conductive portion 22 within the accommodating portion 121, the space occupied by the battery cell 10 itself can be reduced, allowing a battery 100 of the same volume to accommodate a greater number of battery cells 10, thereby increasing the volumetric energy density of the battery 100. Furthermore, by accommodating at least a portion of the conductive portion 22 within the accommodating portion 121, thereby occupying the space within the first terminal 12, the redundancy of the conductive portion 22 within the housing 11 can be reduced to at least some extent, reducing the probability of short circuits between the conductive portion 22 and the active material coating portion 21, thereby reducing the probability of short circuits in the battery cell 10, and improving the operational reliability and stability of the battery cell 10 and the battery 100. Furthermore, accommodating at least a portion of the conductive portion 22 within the accommodating portion 121 also helps stabilize and position the conductive portion 22, thereby increasing its stability and facilitating welding of the conductive portion 22 to the first terminal 12, thereby improving assembly efficiency and thereby improving the reliability of the battery cell 10.

[0286] In some optional embodiments of the present application, please refer to Figures 3, 25 and 26 again. Each of the multiple poles on the shell assembly 1 is a first pole 12 having a receiving portion 121. At this time, more conductive portions 22 can be accommodated in all the first poles 12 to better improve the volume energy density of the battery cell 10.

[0287] In some other optional embodiments of the present application, please refer to Figures 27 and 28, at least one of the multiple poles on the shell assembly 1 is a first pole 12 with an accommodating portion 121 and at least one is a second pole 15 without an accommodating portion 121, so that the first pole 12 and the second pole 15 can be flexibly selected and matched according to actual requirements such as energy density and cost to improve the applicability of the battery cell 10.

[0288] It should be noted that, referring to Figures 27 and 28, when the housing 11 is provided with the second pole 15, a relief groove 18 is defined between the second pole 15 and the housing 11, and at least a portion of the conductive portion 22 is received 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 alleviating problems such as short circuits caused by redundant conductive portions 22.

[0289] In some embodiments of the present application, the accommodating portion 121 can be located on the side of the first pole 12 facing the active material coating portion 21, or on the side of the first pole 12 facing away from the active material coating portion 21. For example, FIG29 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application. Please refer to FIG8 and FIG29. When the accommodating portion 121 is located on the side of the first pole 12 facing the active material coating portion 21, the accommodating portion 121 includes 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. At least a portion of the conductive portion 22 is accommodated in the first accommodating groove 12110.

[0290] 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.

[0291] 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.

[0292] 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, when there is more electrolyte, the service life of the battery cell 10 can be extended; and also 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.

[0293] Furthermore, because the first receiving groove 12110 is located inside the first pole 12, external foreign matter and impurities are less likely 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 operational stability and reliability of the battery cell assembly 2, and thereby improving the stability and reliability of the battery cell 10 and battery 100. Furthermore, the first receiving groove 12110 can be positioned to correspond to the position of the mounting hole 113. In other words, on a projection plane perpendicular to the axial direction R of the first pole 12, the orthographic projection of the first receiving groove 12110 is within the orthographic projection of the mounting hole 113. This allows the first receiving groove 12110 to have a greater depth to accommodate more conductive portions 22, thereby significantly reducing the space occupied by the conductive portions 22 within the housing 11.

[0294] 28 and 29 , in the embodiment of the present application, the connection method between the first pole 12 and the housing 11 is not limited, for example, welding or riveting can be used. For example, when the two are riveted, the housing 11 has a mounting hole 113, and the first pole 12 is riveted to the mounting hole 113. Of course, it is understood that when the two are welded or otherwise coupled, the housing 11 may also have a mounting hole 113, and the first pole 12 may be mounted to the mounting hole 113.

[0295] Specifically, when the housing 11 is provided with a mounting hole 113 and the first pole 12 is mounted in the mounting hole 113 , along 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 surface 122 of the pole to the mounting hole 113 .

[0296] 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 structure formed by two arcs and two straight lines), 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.

[0297] 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.

[0298] It should also 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. 2 , 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.

[0299] In addition, it is worth noting that the first volume V1 of the first receiving tank 12110 is the difference between the total volume V2 of the first receiving tank 12110 and the volume of the first receiving tank 12110 required to accommodate other components except the conductive portion 22 (recorded as the second volume V3), that is, V1 = V2 - V3. It is understandable that when the first receiving tank 12110 does not need to accommodate other components except the conductive portion 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.

[0300] Referring again to Figures 8 and 29, to ensure the stability and reliability of the electrical connection between the active material coating portion 21 and the first electrode 12, in an embodiment of the present application, the electrical connection location between the conductive portion 22 and the first electrode 12 can be located on the wall of the first receiving groove 12110. In this case, the wall of the first receiving groove 12110 forms the first welding surface 120, and the surface of the conductive portion 22 opposite the first welding surface 120 forms the second welding surface 220. For example, the conductive portion 22 and the first electrode 12 can be electrically connected by welding, and the electrical connection location is the welding location of the conductive portion 22 and the first electrode 12. At the same time, the welding method of the conductive portion 22 and the first electrode 12 is not limited, for example, laser welding can be used, and depending on factors such as the position, angle, or structure of the welding part, vertical welding, inclined welding, lap welding, or edge sealing welding can be selected. In other embodiments of the present application, the conductive portion 22 and the first electrode 12 can also be electrically connected by other methods instead of welding, such as by providing conductive glue or conductive nails. To simplify the description, the following description will take the example of welding the conductive portion 22 and the first pole 12 to form an electrical connection, where the welding position is the electrical connection position between the conductive portion 22 and the first pole 12 .

[0301] Specifically, the first electrode 12 includes 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. The first end wall 12111 and the first side wall 12113 enclose a first receiving groove 12110. The electrical connection position between the conductive portion 22 and the first electrode 12 is located on the first end wall 12111 and / or the first side wall 12113. In other words, the conductive portion 22 can be welded to at least one of the first end wall 12111 and the first side wall 12113. In this case, the wall surface of the first end wall 12111 and / or the first side wall 12113 forms the first welding surface 120, and the surface of the conductive portion 22 opposite the first welding surface 120 forms the second welding surface 220.

[0302] In the above technical solution, by arranging the electrical connection position between the conductive portion 22 and the first terminal 12 on at least one of the first end wall 12111 and the first side wall 12113, the first receiving groove 12110 not only serves to accommodate at least a portion of the conductive portion 22, but the groove wall of the first receiving groove 12110 also serves to establish an electrical connection with the conductive portion 22. This simplifies the structure of the first terminal 12, facilitates the processing of the first terminal 12, simplifies the structure of the conductive portion 22, reduces redundancy in the conductive portion 22, and reduces the cost of the conductive portion 22. Furthermore, by utilizing the groove wall of the first receiving groove 12110 to establish an electrical connection with the conductive portion 22, the area where the conductive portion 22 is electrically connected to the first terminal 12 can be set relatively large, which not only reduces the difficulty of electrical connection, but also improves the reliability and stability of the electrical connection, thereby improving the performance of the battery cell 10.

[0303] In addition, since the electrical connection position between the conductive part 22 and the first pole 12 is located in the first receiving groove 12110, it can not only prevent the electrical connection position from protruding from the outside of the first pole 12 and occupying the space outside the first pole 12, but also enable the electrical connection position to be protected by the first pole 12, thereby improving the reliability and stability of the electrical connection between the conductive part 22 and the first pole 12.

[0304] 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.

[0305] Referring again to Figures 8 and 29 , in the embodiment of the present application, the partial shape of the conductive portion 22 matches the partial shape of the first end wall 12111, and they are arranged to fit and electrically connect, such that the location where the conductive portion 22 is electrically connected to 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 to the first end wall 12111, and an electrical connection, such as welding, can be made at the fitting location. This can increase the area of ​​the electrical connection, improving the reliability and stability of the electrical connection.

[0306] In addition, when the electrical connection between the conductive part 22 and the first end wall 12111 is welding, since the first end wall 12111 is located on the side of the first receiving groove 12110 away from the active material coating part 21, the welding operation is facilitated. For example, welding can be performed from the side of the first pole 12 away from the active material coating part 21.

[0307] 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.

[0308] Of course, in other embodiments of the present application, the position where the conductive part 22 is electrically connected to the first end wall 12111 may not extend along the length or width direction of the first end wall 12111. For example, it may be a plurality of discretely arranged points. For example, the conductive part 22 has a plurality of spaced-apart parts that are respectively welded to the first end wall 12111, which will not be elaborated here.

[0309] FIG21 is a partial cross-sectional schematic diagram of a battery cell 10 provided in some embodiments of the present application. Referring to FIG21 , in the embodiments of the present application, when the conductive portion 22 is electrically connected to the first end wall 12111, a first recess 12112 may be provided in the wall of the first receiving tank 12110. The first recess 12112 extends downward away from the active material coating portion 21. At least a portion of the location where the guide portion 22 is electrically connected to the first electrode 12 is located within the first recess 12112. In this case, the bottom of the first recess 12112, i.e., the wall surface of the first recess 12112 away from the active material coating portion 21, forms the first welding surface 120, and the surface of the conductive portion 22 opposite the first welding surface 120 forms the second welding surface 220.

[0310] Exemplarily, the first accommodating groove 12110 has a first end wall 12111 and a first side wall 12113, and a first recess 12112 is provided on the first end wall 12111, and at least a portion of the position where the conductive part 22 is electrically connected to the first end wall 12111 is located within the first recess 12112; at this time, at least a portion of the conductive part 22 can be disposed within the first recess 12112 and connected to the first end wall 12111 of the first accommodating groove 12110 for defining a portion of the first recess 12112.

[0311] In the above technical solution, on the one hand, the first sink groove 12112 can be used to realize pre-positioning and limiting of the electrical connection position of the conductive part 22, which is not only conducive to finding the correct position to realize electrical connection and improve production efficiency, but also helps to improve the stability and reliability of the conductive part 22, and ensure 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 helps to reduce the weight of the first pole 12 and improve the weight energy density of the battery cell 10.

[0312] 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 electrically connected (e.g., by welding) so that the portion where the conductive portion 22 is electrically connected to the first side wall 12113 extends along the first side wall 12113. This increases the area of ​​the electrical connection, thereby improving the reliability and stability of the electrical connection.

[0313] Of course, in other embodiments of the present application, the position where the conductive part 22 is electrically connected to the first side wall 12113 may not extend along the first side wall 12113, for example, it may be a plurality of discretely set points. For example, the conductive part 22 has a plurality of spaced-apart parts that are respectively welded to the first side wall 12113, which will not be elaborated here.

[0314] 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.

[0315] 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 each first side wall 12113 away from the notch of 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.

[0316] In addition, it is worth noting that in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the first terminal 12 may not be located within the first receiving groove 12110. For example, the electrical connection position 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.

[0317] In an embodiment of the present application, please refer to Figure 21. The first pole 12 can also be provided with a first groove 126 as required. The first groove 126 is located on the side of the first pole 12 away from the active material coating portion 21. That is, the surface of the side of the first pole 12 away from the active material coating portion 21 is the pole outer end face 123, and the notch of the first groove 126 is formed on the pole outer end face 123.

[0318] 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 in the direction closer to 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 in the direction closer to the battery cell assembly 2).

[0319] 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 to 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 in the battery 100 that electrically connect the various battery cells 10, so as to make full use of the space inside the first pole 12 and improve the space utilization and volume energy density of the battery 100.

[0320] 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, i.e., 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.

[0321] 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 21 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.

[0322] In some embodiments, the first receiving groove 12110 can be configured in a cross-sectional shape with a length greater than width, such as a rectangle, an ellipse, a racetrack, or the like. The weld mark 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 weld mark 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.

[0323] Referring to FIG. 8 again, the battery cell 10 may further include a slot cover 7 . The slot cover 7 is disposed on the first electrode 12 and covers the opening of the first groove 126 .

[0324] In the above technical solution, by providing a slot cover 7 that covers the first groove 126, the first pole 12 can be indirectly electrically connected to the busbar through the slot cover 7. By adjusting the position and structure of the slot cover 7, the electrical connection between the slot cover 7 and the busbar is more convenient and the electrical connection area is larger. Therefore, the provision of the slot cover 7 facilitates the electrical connection between adjacent battery cells 10 in the battery 100. Since the location where the battery cells 10 are electrically connected is located on the slot cover 7, the electrical connection location between the conductive portion 22 and the first pole 12 can be separated by the first groove 126, reducing interference between the two, and further improving the stability and reliability of the battery cells 10.

[0325] It should be noted that, based on the solution that the accommodating portion 121 includes the first accommodating groove 12110 , the specific structure of the battery cell assembly 2 of the embodiment of the present application is not limited, and for example, may include but is not limited to the following two implementations.

[0326] Figure 30 is a partial cross-sectional schematic diagram of the battery cell assembly 2 provided in some embodiments of the present application. Please refer to Figures 8, 21 and 30. In the first embodiment, 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 pole ear sheets 2211 are structures that are electrically connected to the current collector 211 but are not coated with active materials. They can be formed by directly die-cutting the current collector 211. The plurality of pole ear sheets 2211 converge near the current collector 211 (that is, gather in a direction close to each other) to form a first gathered portion 2212. The plurality of pole ear sheets 2211 converge 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. When the accommodating portion 121 has a first accommodating groove 12110 , at least a portion of the second retracted portion 2213 may be accommodated in the first accommodating groove 12110 .

[0327] 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 can be connected into an integrated plate structure by welding (e.g., ultrasonic welding) to form the second gathered portion 2213. For example, the plurality of tabs 2211 can 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.

[0328] 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.

[0329] 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.

[0330] In the above technical solution, since 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 is accommodated within the first receiving groove 12110. This facilitates the connection between the conductive portion 22 and the first electrode post 12, fully utilizing the space in the first electrode post 12 and improving the volumetric energy density of the battery cell 10. In this case, the surface of the second gathered portion 2213 that opposes the first welding surface 120 forms the second welding surface 220.

[0331] Referring to Figures 8, 21, and 30, in the first embodiment, at least a portion of the first gathered portion 2212 is accommodated within the first receiving groove 12110. In the above technical solution, at least a portion of the first gathered portion 2212 and at least a portion of the second gathered portion 2213 of the electrode lug 221 are both accommodated within the first receiving groove 12110, thereby more fully utilizing the space within the first electrode 12 and further reducing the space occupied by the electrode lug 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 lug 221 within the housing 11 can be further reduced, further reducing the probability of short circuit between the electrode lug 221 and the active material coating portion 21.

[0332] In this embodiment, the second gathered portion 2213 is directly or indirectly electrically connected to the first terminal 12. For example, referring to Figure 8 , when the second gathered portion 2213 is directly electrically connected to the first terminal 12, such as when the second gathered portion 2213 is welded (e.g., laser welded) to the first terminal 12, the structure of the battery cell assembly 2 can be simplified, reducing parts, simplifying the assembly process, and improving assembly efficiency. The method and location of the direct electrical connection between the second gathered portion 2213 and the first terminal 12 are not limited. For example, the electrical connection position between the second gathering portion 2213 and the first pole 12 can be located at the first end wall 12111 and / or the first side wall 12113. Furthermore, the electrical connection position between the second gathering portion 2213 and the first end wall 12111 can extend along the length direction or width direction of the first end wall 12111. Further, the first end wall 12111 has a first groove 12112, and the electrical connection position between the second gathering portion 2213 and the first end wall 12111 can be located in the first groove 12112, and so on. The corresponding technical effects can be referred to the introduction of the above embodiments and will not be repeated here.

[0333] As an optional solution, the conductive portion 22 may also be provided with a transition piece 222 as required. In this case, the second retracted portion 2213 is indirectly electrically connected to the first pole 12. Specifically, referring to FIG21 , when the conductive portion 22 includes the transition piece 222, the transition piece 222 is connected to the second retracted portion 2213, and the conductive portion 22 is electrically connected to the first pole 12 via the transition piece 222. In this case, at least a portion of the transition piece 222 is accommodated within the first receiving groove 12110. In this example, at least a portion of the second retracted portion 2213 is also accommodated within the first receiving groove 12110. However, the first retracted portion 2212 may or may not be accommodated within the first receiving groove 12110.

[0334] 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).

[0335] In the above technical solution, on the one hand, by accommodating at least a portion of the second accordion portion 2213 and at least a portion of the adapter plate 222 within the first receiving 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. Furthermore, when at least a portion of the first accordion portion 2212, at least a portion of the second accordion portion 2213, and at least a portion of the adapter plate 222 are all accommodated within the first receiving groove 12110, the space within the first electrode 12 can be further fully utilized, more effectively 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.

[0336] On the other hand, by using the adapter plate 222 to achieve indirect electrical connection between the second gathered 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 gathered portion 2213, thereby making the welding between the adapter plate 222 and the first pole 12 more secure, reducing the risk of welding cracking, and further improving the reliability and stability of the battery cell 10; at the same time, electrically connecting the first pole 12 and the pole tab 2211 through the adapter plate 222 can also simplify the structure of the pole tab 2211.

[0337] Among them, the direct electrical connection method and position of the adapter plate 222 and the first pole 12 are not limited. For example, the adapter plate 222 is electrically connected to the first pole 12 by welding. For example, the electrical connection position of the adapter plate 222 and the first pole 12 can be located at the first end wall 12111 and / or the first side wall 12113. Further, the position where the adapter plate 222 is electrically connected to the first end wall 12111 can extend along the length direction or width direction of the first end wall 12111. Further, the first end wall 12111 has a first sink 12112, and the position where the adapter plate 222 is electrically connected to the first end wall 12111 can be located in the first sink 12112, etc. The corresponding technical effects can be referred to the introduction of the above embodiment and will not be repeated here. When the electrical connection position between the adapter plate 222 and the first pole 12 is located at 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 cost can be lowered.

[0338] Referring to Figures 21 and 30 , 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 has 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.

[0339] In the above technical solution, compared with the solution including the adapter plate 222 in the first embodiment, in the second embodiment, at least part 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 part 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, so as to meet different structural design requirements. At this time, the surface of the adapter plate 222 opposite to the first welding surface 120 forms a second welding surface 220.

[0340] In the above technical solution, by accommodating at least a portion of the adapter plate 222 in the first accommodating groove 12110, 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 volume energy density of the battery cell 10, and reducing the probability of short circuit between the adapter plate 222 and the active material coating part 21, reducing the risk of short circuit of the battery cell assembly 2, and thus improving the stability and reliability of the battery cell 10.

[0341] 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.

[0342] 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.

[0343] Figure 31 is a diagram of various tab folding schemes for the battery cell assembly provided in some embodiments of the present application. Please refer to Figures 30 and 31. 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 position between the two electrode assemblies 2a to form a symmetrical folding form (for example, as shown in Figures 30 and 31 (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 folding form (for example, as shown in Figures 31 (b) and 31 (c)). In addition, the electrode assembly 2a can be in a full-tab form (for example, as shown in Figure 31 (a)) or a half-tab form (for example, as shown in Figures 30, 31 (b) and 31 (c)).

[0344] Of course, 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.

[0345] 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.

[0346] For example, FIG32 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application. Referring to FIG32 , in the embodiments of the present application, the accommodating portion 121 may also be configured to include a second accommodating groove 12120. The surface of the first electrode 12 on the side away from the active material coating portion 21 is the electrode outer end surface 123. The notch of the second accommodating groove 12120 is formed on the electrode outer end surface 123. The second accommodating groove 12120 is connected to the interior of the housing 11 through the first through-hole 12130. The conductive portion 22 is provided through the first through-hole 12130 and is at least partially accommodated within the second accommodating groove 12120. In this case, the groove wall surface of the second accommodating groove 12120 forms the first welding surface 120, and the surface of the conductive portion 22 opposite the first welding surface 120 forms the second welding surface 220.

[0347] 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.

[0348] In the above technical solution, please refer to Figure 32. 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.

[0349] 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.

[0350] 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 is at least partially received in the second receiving groove 12120 , the electrical connection position between the conductive portion 22 and the first pole 12 is not limited.

[0351] 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 electrical connection position 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 .

[0352] In the above technical solution, the electrical connection position between the conductive part 22 and the first pole 12 is set on the wall of the first through-hole 12130, thereby facilitating the electrical connection operation between the conductive part 22 and the first pole 12 through the second receiving groove 12120. Moreover, when the electrical connection area between the conductive part 22 and the first pole 12 is large, the electrical connection between the conductive part 22 and the first pole 12 can be utilized to achieve sealing of the first through-hole 12130, thereby saving sealing costs, reducing electrolyte leakage, and saving sealing parts.

[0353] 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.

[0354] 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 electrical connection position 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.

[0355] Specifically, FIG33 is a partial cross-sectional schematic diagram of a battery cell 10 provided in some embodiments of the present application. Referring to FIG32 and FIG33 , the first electrode 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 adjacent to the active material coating portion 21. The second end wall 12121 and the second side wall 12123 enclose a second receiving groove 12120. A first through-hole 12130 is provided in the second end wall 12121. The electrical connection between the conductive portion 22 and the first electrode 12 is located on the second end wall 12121 and / or the second side wall 12123. The surface of the second end wall 12121 and / or the second side wall 12123 forms the first welding surface 120, and the surface of the conductive portion 22 opposite the first welding surface 120 forms the second welding surface 220.

[0356] More specifically, the conductive portion 22 and the first pole 12 can be electrically connected by welding, so the welding position is the electrical connection position between the conductive portion 22 and the first pole 12. In other embodiments of the present application, the conductive portion 22 and the first pole 12 can also be electrically connected by other methods instead of welding, such as by providing conductive glue or conductive nails, which will not be described in detail here.

[0357] To simplify the description, the following description uses the example of welding the conductive portion 22 to the first pole 12 to form an electrical connection, where the welding location is the electrical connection location between the conductive portion 22 and the first pole 12. For example, in some embodiments, the electrical connection location between the conductive portion 22 and the first pole 12 is located at the second end wall 12121 and / or the second side wall 12123, and the conductive portion 22 may be welded to at least one of the second end wall 12121 and the second side wall 12123.

[0358] In the above technical solution, by disposing the electrical connection point between the conductive portion 22 and the first terminal 12 on at least one of the second end wall 12121 and the second side wall 12123, the second receiving groove 12120 not only serves to accommodate at least a portion of the conductive portion 22, but the groove wall of the second receiving groove 12120 also serves to achieve electrical connection with the conductive portion 22. This simplifies the structure of the first terminal 12 and facilitates the processing of the first terminal 12. Furthermore, since the first through-hole 12130 is provided in the second end wall 12121, the conductive portion 22 can be easily extended into the second receiving groove 12120 through the first through-hole 12130, thereby simplifying the structure of the conductive portion 22, reducing redundancy of the conductive portion 22, and reducing the cost of the conductive portion 22. Moreover, the opening direction of the slot of the second receiving groove 12120 makes it easy to electrically connect the conductive part 22 with the slot wall of the second receiving groove 12120 through the slot of the second receiving groove 12120, which can reduce the difficulty of electrical connection. Moreover, by utilizing the slot wall of the second receiving groove 12120 to achieve electrical connection with the conductive part 22, the area where the conductive part 22 is electrically connected to the first pole 12 can be relatively large, which can improve the reliability and stability of the electrical connection, thereby improving the performance of the battery cell 10.

[0359] In addition, since the electrical connection position between the conductive part 22 and the first pole 12 is located in the second receiving groove 12120, it can not only prevent the electrical connection position from protruding from the outside of the first pole 12 and occupying the space outside the first pole 12, but also enable the electrical connection position to be protected by the first pole 12, thereby improving the reliability and stability of the electrical connection between the conductive part 22 and the first pole 12.

[0360] Referring again to Figures 32 and 33 , 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 so as to be electrically connected thereto. This allows the portion where the conductive portion 22 is electrically connected to the second end wall 12121 to extend along the length or width of the second end wall 12121. For example, if 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 electrical connection being made there, such as by welding. This can increase the area of ​​the electrical connection, improving the reliability and stability of the electrical connection.

[0361] 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.

[0362] For example, referring to Figures 32 and 33 , when the second end wall 12121 is a flat plate, the angle θ between the second end wall 12121 and the axial direction R of the first electrode 12 is 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.

[0363] For another example, FIG34 is a partial cross-sectional schematic diagram of a battery cell 10 provided in some embodiments of the present application. Referring to FIG34 , the angle θ between the second end wall 12121 and the axial direction R of the first terminal 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 conductive portion 22 extends a greater distance along the second end wall 12121, thereby enhancing the reliability of the electrical connection. For example, the angle θ between the second end wall 12121 and the axial direction R of the first terminal 12 can be 90°-145°, such as 100°, 110°, 120°, 130°, 140°, and so on. This makes the second end wall 12121 easier to process and facilitates electrical connection with the conductive portion 22, while also making more efficient use of the space within the first terminal 12 to accommodate the conductive portion 22.

[0364] For another example, FIG35 is a partial cross-sectional schematic diagram of a battery cell 10 provided in some embodiments of the present application. In conjunction with FIG35 , the angle θ between the second end wall 12121 and the axial direction R of the first terminal 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 away from the active material coating portion 21. As a result, the distance the conductive portion 22 extends along the second end wall 12121 can be increased, thereby improving the reliability of the electrical connection. For example, the angle θ between the second end wall 12121 and the axial direction R of the first terminal 12 can be 45°-90°, such as 50°, 60°, 70°, 80°, and so on. This allows for easier processing of the second end wall 12121 and facilitates electrical connection to the conductive portion 22, while also allowing for more efficient use of the space within the first terminal 12 to accommodate the conductive portion 22.

[0365] Of course, in other embodiments of the present application, the position where the conductive part 22 is electrically connected to the second end wall 12121 may not extend along the length or width direction of the second end wall 12121, and it may also be a plurality of discretely arranged points. For example, the conductive part 22 has a plurality of spaced-apart parts that are respectively welded to the second end wall 12121, which will not be elaborated here.

[0366] Please refer to Figure 33 again. Regardless of the specific value of the angle θ between the second end wall 12121 and the axial direction R of the first pole 12, in the embodiment of the present application, when the conductive portion 22 is electrically connected to the second end wall 12121, the second receiving groove 12120 can be provided with a second sinking groove 12122 as required. The sinking direction of the second sinking groove 12122 is the direction close to the active material coating portion 21. The position where the conductive portion 22 is electrically connected to the first pole 12 is at least partially located in the second sinking groove 12122.

[0367] Exemplarily, the second accommodating groove 12120 has a second end wall 12121 and a second side wall 12123, and a second groove 12122 is provided on the second end wall 12121, and the position where the conductive part 22 is electrically connected to the second end wall 12121 is at least partially located in the second groove 12122; at this time, the second groove 12122 is a groove formed by a part of the second end wall 12121 sinking toward the end close to the active material coating part. At this time, the bottom of the second groove 12122, that is, the wall surface of the second groove 12122 close to the active material coating part 21 forms a first welding surface 120, and the surface of the conductive part 22 opposite to the first welding surface 120 forms a second welding surface 220.

[0368] 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 electrical connection, so that the second groove 12122 can be used to pre-position and limit the electrical connection position of the conductive part 22, which is conducive to finding the correct position to achieve electrical connection, improve production efficiency, and improve 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.

[0369] 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 electrically connected (e.g., welded) so that the portion where the conductive portion 22 is electrically connected to the second side wall 12123 extends along the second side wall 12123. This can increase the area of ​​the electrical connection, thereby improving the reliability and stability of the electrical connection.

[0370] It should also be noted that, in other embodiments of the present application, the position where the conductive part 22 is electrically connected to 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 part 22 has a plurality of spaced-apart parts that are respectively welded to the second side wall 12123, which will not be elaborated here.

[0371] 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.

[0372] It should also be noted that the second receiving groove 12120 is not limited to the form defined by the second end wall 12121 and the second side wall 12123. For example, in some embodiments, Figure 36 is a partial cross-sectional schematic diagram of the battery cell provided in some embodiments of the present application. Please refer to Figure 36. One end of the notch of each second side wall 12123 away from the second receiving groove 12120 extends to the first perforation 12130, so that the second receiving 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.

[0373] In some embodiments, referring to FIG. 48 , the accommodating portion 121 may have a third accommodating groove 12140 and a second accommodating groove 12120 at the same time. The second accommodating groove 12120 is located on the side of the third accommodating groove 12140 away from the active material coating portion 21. The third accommodating groove 12140 is a groove body, which is a groove-shaped structure with a certain depth. The notch of the third accommodating groove 12140 is formed on the inner end face 122 of the first pole 12 on the side close to the active material coating portion 21. The notch of the second accommodating groove 12120 is formed on the inner end face 122 of the first pole 12. On the outer end face 123 of the first pole 12 on the side away from the active material coating portion 21, the third accommodating groove 12140 and the second accommodating groove 12120 are connected through the first through-hole 12130. At this time, a portion of the conductive portion 22 is located in the third accommodating groove 12140, and the conductive portion 22 is also passed through the first through-hole 12130, and the remaining portion of the conductive portion 22 is located in the second accommodating groove 12120, so that the space in the first pole 12 can be more fully utilized, reducing the space occupied by the conductive portion 22 in the shell 11.

[0374] 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, referring again to FIG. 36 , 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.

[0375] Referring again to FIG. 32 , in the embodiment of the present application, the connection method between the first pole 12 and the housing 11 is not limited, and can be welding or riveting. For example, when the two are riveted, the housing 11 has a mounting hole 113, and the first pole 12 is riveted to the mounting hole 113. Of course, it is understood that when the two are welded or otherwise coupled, the housing 11 may also have a mounting hole 113, and the first pole 12 may be mounted to the mounting hole 113.

[0376] Optionally, referring to Figure 32, 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.

[0377] In some embodiments, referring again to FIG. 32 , along the axial direction R of the first pole 12 , 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 .

[0378] 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, for example, see the shape shown in Figure 38(b).

[0379] 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.

[0380] 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.

[0381] 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.

[0382] 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.

[0383] For example, FIG37 is an enlarged partial view at W in FIG3 ; FIG38 is an orthographic view of various first electrodes 12 provided in some embodiments of the present application. Referring to FIG37 and FIG38 , in the embodiments of the present application, the shape of the first through-hole 12130 can be 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 an elongated strip, the second receiving groove 12120 can also be configured with a cross-sectional shape that is longer than its width, such as a rectangular, elliptical, or racetrack shape. In this case, the length of the first through-hole 12130 can be aligned with the length of the cross-sectional shape of the second receiving groove 12120, thereby fully utilizing space. Furthermore, the weld mark formed by welding the conductive portion 22 to the first electrode 12 can be an elongated strip parallel to the length 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.

[0384] 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 part 22. For example, when there is only one first through-hole 12130 opened on the second receiving groove 12120, in some examples, please refer to Figures 37 and 38, the first through-hole 12130 can be centered relative to the second receiving groove 12120. In other examples, Figure 39 is a partial cross-sectional schematic diagram of the battery cell 10 provided in some embodiments of the present application. Please refer to Figure 39, the first through-hole 12130 can also be offset relative to the center of the second receiving groove 12120. For example, in some embodiments, referring to Figure 39, 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, thereby increasing the available area of ​​the second end wall 12121 to increase the welding area between the conductive part 22 and the second end wall 12121.

[0385] It is understood that after the conductive portion 22 passes through the first through-hole 12130, it will be folded 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 37), thereby appropriately reducing the size of the second receiving groove 12120 and enhancing the structural compactness and strength. Alternatively, after passing through the first through-hole 12130, the conductive portion 22 can be folded toward opposite sides simultaneously (Figure 40 is a partial cross-sectional schematic diagram of the battery cell 10 provided in some embodiments of the present application, see Figure 40), thereby reducing the thickness of the weld, reducing the welding heat input, and thus reducing problems such as particle splashing.

[0386] For example, when there are multiple first through-holes 12130 opened on the second accommodating 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 position relationship of the multiple first through-holes 12130. For example, when there are two first through-holes 12130 opened on the second accommodating groove 12120 and they are far away from each other (Figure 41 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application, combined with Figure 41), the two conductive portions 22 passing through the two first through-holes 12130 can be folded in a direction close to each other; and when there are two first through-holes 12130 opened on the second accommodating 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.

[0387] 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.

[0388] In addition, in some embodiments, please refer to Figures 39 and 40, the first through-hole 12130 can be centered relative to the active material coating portion 21, but the position of the first through-hole 12130 relative to the second receiving groove 12120 is not limited, and can be centered or offset. Since the first through-hole 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.

[0389] In some embodiments, referring to FIG. 40 , a first 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 first sealing member 6 to 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.

[0390] Figure 42 is a structural explosion diagram of the battery cell 10 provided in some embodiments of the present application; Figure 43 is a partial cross-sectional schematic diagram of the shell assembly 1 provided in some embodiments of the present application. In combination with Figure 42 and Figure 43, in the 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.

[0391] 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.

[0392] 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 slot 12120. For example, in some embodiments, referring to FIG. 44 , 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 slot 12120. The first cover plate 13 and the first terminal 12 are then welded to close the notch of the second receiving slot 12120.

[0393] It should also be noted that the specific composition of the first cover plate 13 is not limited. For example, in some optional embodiments, FIG43 is a partial cross-sectional schematic diagram of a housing assembly provided in some embodiments of the present application; FIG44 is an exploded view of the housing assembly shown in FIG43; and FIG45 is an exploded view of the first cover plate 13 shown in FIG44. Referring to FIG43-45, 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 is mated with and electrically connected to the first pole 12, and the second conductive member 132 is mated with and electrically connected to the first conductive member 131.

[0394] 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.

[0395] 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.

[0396] Referring again to Figures 43-45, in some optional examples, the first conductive member 131 is located between the second receiving groove 12120 and the second conductive member 132. In the above technical solution, since the first conductive member 131 is located between the second receiving groove 12120 and the second conductive member 132, it can separate the second receiving groove 12120 from the second conductive member 132. Therefore, when the electrolyte in the housing 11 enters the second receiving groove 12120 through the first through-hole 12130, the first conductive member 131 can prevent the electrolyte from contacting the second conductive member 132, thereby solving the problem of corrosion of the second conductive member 132 by the electrolyte.

[0397] It is worth noting that the coupling method between the first conductive member 131 and the second conductive member 132 is not limited. For example, in some embodiments, referring to Figures 43-45, 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 second receiving slot 12120, so that the second conductive member 132 is exposed through 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.

[0398] 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.

[0399] 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 conductive member 131 and the second conductive member 132 can be reduced, the stability and convenience of the cooperation between the first conductive member 131 and the second conductive member 132 can be improved, and 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. On the other hand, since 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 achieve electrical connection between the second conductive member 132 and the current collecting component outside the first terminal 12.

[0400] 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.

[0401] 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, Figure 46 is a partial cross-sectional schematic diagram of the battery cell 10 provided in some embodiments of the present application, and Figure 47 is a structural explosion diagram of the battery cell shown in Figure 46. Please refer to Figures 46 and 47. The first cover plate 13 can also be set as a non-composite form made of the same material, for example, to adapt to the positive electrode column, which will not be elaborated here.

[0402] Referring again to Figures 43-45 , 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.

[0403] 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.

[0404] Referring again to Figures 43-46, 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 on the first pole 12 is formed as a guide slope 12126. The guide slope 12126 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 slope, 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 slope 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.

[0405] Specifically, referring to Figures 43-45, 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.

[0406] 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.

[0407] 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.

[0408] Referring again to Figures 43-45 , in the embodiment of the present application, the first cover plate 13 may further include stress relief grooves 133 as needed. The stress relief grooves 133 are located in the outer peripheral region of the first cover plate 13 to assist in stress relief for the first cover plate 13. In the above technical solution, by providing the stress relief grooves 133 on the first cover plate 13, 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 terminal 12 can be relieved, thereby improving issues such as deformation or damage to the first cover plate 13 caused by stress.

[0409] 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.

[0410] Figure 47 is a structural explosion diagram of the battery cell shown in Figure 46. Please refer to Figures 46 and 47. In the embodiment of the present application, the shell assembly 1 can also be provided with a second cover plate 14 as needed. The second cover plate 14 covers the first through-hole 12130 and the conductive part 22 located in the second receiving groove 12120.

[0411] 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.

[0412] 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.

[0413] For example, as shown in Figures 46 and 47, 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.

[0414] In the embodiment of the present application, the first pole 12 can be an integrally formed pole or a composite pole formed in separate parts. Referring again to Figures 46 and 47 , for example, the first pole 12 can include 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 receiving portion 121 is provided on the first pole portion 124, or the receiving portion 121 is provided on the first pole portion 124 and the second pole portion 125. The conductive portion 22 is electrically connected to the first pole portion 124.

[0415] 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, etc., which is conducive to the assembly and electrical connection of the first pole 12 with related components, reducing the mutual interference between the electrical connection position of the first pole 12 and the conductive portion 22 and the electrical connection position of the first pole 12 and the busbar component of the battery 100, thereby improving the reliability and stability of the battery cell 10.

[0416] For example, when the material of the conductive part 22 is different from the material of the busbar component, 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, which is conducive to the welding of the second pole part 125 and the busbar component, and 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.

[0417] 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.

[0418] For example, please refer to Figures 46-47. 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 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 are made of the same material and can be effectively welded.

[0419] In an embodiment of the present application, when the 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.

[0420] Figure 48 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application. Please refer to Figure 48. In the third embodiment, 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 to form a first gathered portion 2212. The plurality of pole ear sheets 2211 converge 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. When the accommodating portion 121 has a second accommodating groove 12120 , at least a portion of the second gathered portion 2213 is accommodated within the second accommodating groove 12120 . In this case, the groove wall of the second accommodating groove 12120 forms the first welding surface 120 , and the surface of the second gathered portion 2213 opposite the first welding surface 120 forms the second welding surface 220 .

[0421] It is worth noting that the specific structure of the battery cell assembly 2 in this third embodiment is substantially the same as that of the battery cell assembly 2 in the first embodiment above. For details, reference may be made to the description of the first embodiment and will not be repeated here. In this third embodiment, because the tab portion 221 includes a second gathered portion 2213 formed by converging and connecting a plurality of tab sheets 2211, at least a portion of the second gathered portion 2213 can be easily accommodated within the second receiving groove 12120, facilitating assembly of the conductive portion 22 with the first pole 12.

[0422] In some optional examples, please refer to Figure 48, 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.

[0423] 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.

[0424] Please refer to Figure 48. In this third embodiment, in addition to the second accommodating groove 12120, the accommodating portion 121 may also have a third accommodating groove 12140. The third accommodating groove 12140 is located on the side of the second accommodating groove 12120 close to the active material coating portion 21. The surface of the first pole 12 facing the active material coating portion 21 is the pole inner end face 122, 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. At this time, at least a portion of the first retracted portion 2212 can be accommodated in the third accommodating groove 12140.

[0425] In the above technical solution, at least a portion of the first folded portion 2212 of the pole ear portion 221 is accommodated in the third accommodating groove 12140, and at least a portion of the second folded portion 2213 is accommodated 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 pole ear portion 221 in the shell 11 can be further reduced to accommodate a larger active material coating portion 21, thereby improving the energy density of the battery cell 10, and can better reduce the redundancy of the pole ear portion 221 in the shell 11, further reduce the probability of short circuit between the pole ear portion 221 and the active material coating portion 21, and further reduce the risk of the pole ear portion 221 being inverted toward the active material coating portion 21.

[0426] It should be noted that the specific shape of the third receiving groove 12140 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. In the embodiment of the present application, the third receiving groove 12140 can be configured in a shape with a cross-sectional length greater than its width, such as a rectangular, elliptical, or racetrack-shaped shape, to facilitate the storage of the first gathering portion 2212.

[0427] In a third embodiment, the second folded portion 2213 is electrically connected directly or indirectly to the first terminal 12. For example, when the second folded portion 2213 is electrically connected directly to the first terminal 12, such as when the second folded portion 2213 is welded to the first terminal 12, the structure of the battery cell assembly 2 can be simplified, reducing parts, simplifying the assembly process, and improving assembly efficiency. The method and location of the direct electrical connection between the second folded portion 2213 and the first terminal 12 are not limited. For example, the electrical connection position between the second gathering portion 2213 and the first pole 12 can be located at the second end wall 12121 and / or the second side wall 12123. Furthermore, the electrical connection position between the second gathering portion 2213 and the second end wall 12121 can extend along the length direction or width direction of the second end wall 12121. Further, the second end wall 12121 has a second groove 12122, and the electrical connection position between the second gathering portion 2213 and the second end wall 12121 can be located in the second groove 12122, and so on. The corresponding technical effects can be referred to the introduction of the above embodiments and will not be repeated here.

[0428] As an optional solution, the conductive portion 22 can also be provided with a transition piece 222 as required, in which case the second retracted portion 2213 is indirectly electrically connected to the first pole 12. Specifically, FIG49 is a partial cross-sectional schematic diagram of a battery cell 10 provided in some embodiments of the present application. Referring to FIG49, when the conductive portion 22 includes a transition piece 222, the transition piece 222 is connected to the second retracted portion 2213, and the conductive portion 22 is electrically connected to the first pole 12 via the transition piece 222. At this time, at least a portion of the transition piece 222 is accommodated in the second receiving groove 12120. In this example, at least a portion of the second retracted portion 2213 is also accommodated in the second receiving groove 12120.

[0429] 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).

[0430] In the above technical solution, by accommodating at least a portion of the second folded portion 2213 and at least a portion of 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 extended into the second receiving groove 12120.

[0431] 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.

[0432] Among them, the direct electrical connection method and position of the adapter plate 222 and the first pole 12 are not limited. For example, the adapter plate 222 is electrically connected to the first pole 12 by welding. For example, the electrical connection position of the adapter plate 222 and the first pole 12 can be located at the second end wall 12121 and / or the second side wall 12123. Further, the position where the adapter plate 222 is electrically connected to the second end wall 12121 can extend along the length direction or width direction of the second end wall 12121. Further, the second end wall 12121 has a second sink 12122, and the position where the adapter plate 222 is electrically connected to the second end wall 12121 can be located in the second sink 12122, etc. The corresponding technical effects can be referred to the introduction of the above embodiment and will not be repeated here. When the electrical connection position between the adapter plate 222 and the first pole 12 is located at the second end wall 12121 and / or the second side wall 12123, since at least part of the adapter plate 222 is accommodated in the second accommodating groove 12120, the structure of the adapter plate 222 can be simplified, redundancy can be reduced, and cost can be lowered.

[0433] Referring to FIG. 49 , in a fourth 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 has a second accommodating groove 12120, at least a portion of the transition piece 222 can be accommodated in the second accommodating groove 12120 and electrically connected to the first electrode 12.

[0434] In the above technical solution, compared with the above third solution including the adapter plate 222, in this fourth solution, at least part of the adapter plate 222 is accommodated in the second accommodating groove 12120, but the relative position of the pole ear portion 221 and the second accommodating groove 12120 is not limited, that is, at least part of the pole ear portion 221 can be accommodated in the second accommodating groove 12120, and the pole ear portion 221 can also be completely located outside the second accommodating groove 12120, thereby meeting different structural design requirements.

[0435] 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.

[0436] 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.

[0437] Figure 50 is a partial cross-sectional schematic diagram of the battery cell 10 provided in some embodiments of the present application. Please refer to Figure 50. In some other embodiments of the present application, the accommodating portion 121 has a fourth accommodating groove 12150, and the fourth accommodating groove 12150 is a groove body, which is a groove-shaped structure with a certain depth. The surface of the first pole 12 away from the active material coating portion 21 is the pole outer end face 123, and 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 may be passed through the second through-hole 12160, and the electrical connection position between the conductive part 22 and the first pole 12 is located at the hole wall of the second through-hole 12160 formed by the first pole 12.

[0438] In the above embodiment, by providing the fourth receiving groove 12150, it is possible to easily achieve electrical connection between the conductive portion 22 and the wall of the second through-hole 12160. Furthermore, in some cases, the electrical connection between the conductive portion 22 and the first electrode 12 can be utilized 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 operation. Furthermore, by controlling the weld mark, the weld mark and the conductive portion 22 can be utilized to seal the second through-hole 12160, thereby improving the problem of electrolyte leakage from the housing 11 through the second through-hole 12160.

[0439] 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.

[0440] 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.

[0441] It should be noted that the 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, FIG51 is a partial cross-sectional schematic diagram of the battery cell 10 provided in some embodiments of the present application. Referring to FIG51 , the accommodating portion 121 may only have the 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 wall of the third through-hole 12170 formed in the first pole 12, 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 surface 123 outside the third through-hole 12170. In addition, the shape of the third through-hole 12170 is not limited. It can be a regular-shaped hole with a uniform cross-section, or a variable-shaped hole with unequal cross-sections, etc. Furthermore, the cross-sectional shape of the third through-hole 12170 is not limited. For example, it can be an elongated strip, such as a rectangle, an ellipse, or a racetrack, etc., to match the sheet-shaped partial shape of the conductive portion 22, thereby facilitating the sheet-shaped partial portion of the conductive portion 22 to pass through the third through-hole 12170. This will not be described in detail here.

[0442] That is, it should be noted that in the embodiments of the present application, no matter what the structure of the conductive part 22 is, when the conductive part 22 only includes the pole ear structure, the second welding surface 220 is the upper surface of the second folded portion 2213 close to the first pole 22; when the conductive part 22 includes the adapter plate 222, the second welding surface 220 is the upper surface of the adapter plate 222 close to the pole 22.

[0443] Figure 52 is a partial cross-sectional schematic diagram of a battery cell provided in some embodiments of the present application; Figure 53 is a schematic diagram of the cooperation between the battery cell assembly and the bracket provided in some embodiments of the present application; Figure 54 is a cross-sectional view along the CC line in Figure 53. Combined with Figures 52-54, in an embodiment of the present application, the battery cell 10 also includes a bracket 3, which is located in the shell 11, and the bracket 3 is located on the side of the active material coating part 21 close to the first pole 12. The bracket 3 has an avoidance hole 31 for avoiding the conductive part 22. The conductive part 22 can pass through the avoidance hole 31 and extend to the side of the bracket 3 away from the active material coating part 21 to be welded with the first pole 12, thereby ensuring the normal charging and discharging operations of the battery cell 10.

[0444] 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.

[0445] Please refer to Figures 52 to 54 again. Optionally, the bracket 3 is provided with a guide portion 32, which surrounds at least a portion of the avoidance hole 31, and the guide portion 32 at least partially extends to the accommodating portion 121.

[0446] It is worth noting that the guide portion 32 protrudes from the bracket 3 and extends into the 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 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.

[0447] Please refer to Figures 52 to 54 again. 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.

[0448] In the above technical solution, by providing a third groove 38 on the bracket 3, at least a 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, helping to reduce the space occupied by the bracket 3 in the shell 11, and helping to improve the volume energy density of the battery cell 10.

[0449] 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.

[0450] Please refer to Figures 52-54 again. Optionally, in an embodiment of the present application, 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 a pole ear 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 to form a first gathered portion 2212. The plurality of pole ear sheets 2211 converge 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 first gathered portion 2212 is accommodated in the second hole segment 312. The second gathered portion 2213 is passed through the first hole segment 311.

[0451] 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.

[0452] In some embodiments of the present application, the bracket 3 is an integral structure or a split structure. Figure 55 is a schematic structural diagram of the integral bracket 3 provided in some embodiments of the present application. Please refer to Figure 55. When the bracket 3 is an integral structure, the avoidance hole 31 is formed in the form of a through hole that passes through the bracket 3. As a result, the integral structure of the bracket 3 is easy to process, and the reliability of the bracket 3 is better, and it is convenient to assemble the bracket 3 with the shell assembly 1, thereby improving assembly efficiency and matching stability. It is understandable that how the bracket 3 is processed can be specifically selected according to the material of the bracket 3. For example, when the bracket 3 is an insulating plastic part, the integral structure of the bracket 3 can be obtained by injection molding.

[0453] FIG56 is a schematic diagram of the structure of a split bracket 3 provided in some embodiments of the present application. Referring to FIG56 , when the bracket 3 is a split structure, the bracket 3 includes a detachable first bracket 33 and a second bracket 34. The first bracket 33 and the second bracket 34 are both long, plate-like structures. The two can be detachably connected, for example, they can be plugged in or snapped together to facilitate assembly. At the same time, the first bracket 33 has a semi-hole structure on the side close to the second bracket 34, and the second bracket 34 is also provided with another semi-hole structure of the same shape close to the first bracket 33. The semi-hole structure of the first bracket 33 and the semi-hole structure of the second bracket 34 together form an annular avoidance hole 31. That is, the avoidance hole 31 is defined between the first bracket 33 and the second bracket 34.

[0454] 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.

[0455] 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.

[0456] Figure 57 is a partial cross-sectional schematic diagram of the battery cell assembly 2 and the bracket 3 provided in some embodiments of the present application; Figure 58 is a structural exploded view of the battery cell assembly 2, the bracket 3 and the shell assembly 1 provided in some embodiments of the present application. Please refer to Figures 52, 57 and 58. In the embodiments of the present application, the structure of the bracket 3 is not limited to this. For example, the edge of the bracket 3 can also be provided with a shell entry guide surface 35. The shell entry guide surface 35 can be an inclined surface or a curved surface, and is projected along the axial direction R of the first pole 12. The orthographic projections of the active material coating portion 21 are all located 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 preassembled together, and then this preassembled assembly can be installed into the housing 11. During installation, the bracket 3 is located 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 can reduce 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. In addition, the contact area between the bracket 3 and the active material coating portion 21 can be increased, which can reduce stress concentration problems and eliminate other structural components.

[0457] Please refer to Figure 57. In the embodiment 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 the 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.

[0458] Please refer to Figure 57. In the 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 part 21 near 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 part 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 part 21 to improve the problem of carbon powder falling off the edge of the active material coating part 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.

[0459] For example, referring to Figure 57, 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. 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.

[0460] Specifically, referring to Figure 28, 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. 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.

[0461] 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.

[0462] For example, in some embodiments, Figure 59 is a structural exploded view of the first pole 12, the shell 11, and the insulating sealing component 8 provided in some embodiments of the present application; Figure 60 is an assembly view of the first pole 12 shown in Figure 59, the shell 11, and the insulating sealing component 8; Figure 61 is a structural schematic diagram of the first pole 12 provided in some embodiments of the present application. Combined with Figures 59-61, the first pole 12 can be an integrated structure and riveted to the shell 11, thereby improving the assembly efficiency of the first pole 12 and reducing the height of the first pole 12 protruding from the surface of the shell 11, which is beneficial to improving energy density and improving compactness.

[0463] Specifically, please refer to Figures 59 to 61. Before the first pole 12 is riveted, it can include a stopper 1281 and a penetration portion 1282. During assembly, the stopper 1281 is stopped inside the shell 11, and the penetration portion 1282 is penetrated into the mounting hole 113. Then, the portion of the penetration portion 1282 located outside the shell 11 is riveted to form a flange portion 1283. The flange portion 1283 is stopped outside the shell 11, thereby realizing the installation of the first pole 12. At this time, the stopper 1281 can be formed as a second limit platform 12c, the portion of the penetration portion 1282 that cooperates with the mounting hole 113 can be formed as the pole body 12a, and the flange portion 1283 can be formed with a first limit platform 12b.

[0464] Optionally, referring to FIG60 , the length x of the flange portion 1283 may be greater than or equal to 1 mm, and the thickness t1 may be greater than or equal to 2 mm, to improve the riveting strength of the first pole 12. When the length x of the flange portion 1283 is less than 1 mm and / or the thickness t1 is less than 2 mm, the reliability of the first pole 12 and the housing 11 may be reduced under strong vibration.

[0465] In some optional embodiments, referring to FIG. 9 to FIG. 19 , there are multiple first poles 12 having accommodating portions 121 , and all of them are located on the same side surface of the housing 11 , thereby facilitating installation and improving assembly efficiency.

[0466] 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 wall (denoted as the first wall 110) in the height direction of the housing 11, 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.

[0467] For example, in the examples of Figures 9-14 , 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, the portion of the first pole 12 located outside the housing 11 (referred to as the pole exterior, which includes the first stop 12b, or includes the portion of the pole body 12a located outside the housing 11 and the first stop 12b) is annular. Along the length of the first wall 110, the inner ring length a1 of the pole exterior 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 exterior 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 collecting component, thereby further improving the current carrying capacity of the first pole 12. For example, the inner ring length a1 of the pole exterior is greater than or equal to 50 mm, and the inner ring width b1 of the pole exterior is greater than or equal to 30 mm.

[0468] In addition, referring to Figures 9-14, when the first wall 110 has two first poles 12, and the two first poles 12 are spaced apart along the length of the first wall 110, in some optional embodiments, the first pole 12 includes a portion located within the housing 11 (referred to as the pole interior, the pole interior including the second limiting platform 12c, or the pole interior including the portion of the pole body 12a located within the housing 11 and the second limiting platform 12c). 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 be electrically connected to 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.

[0469] For another example, 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, with a total of two groups spaced apart along the length of the first wall 110. Optionally, the portion of the first pole 12 located outside the housing 11 (denoted as the pole outer portion, which may include the first limit platform 12b) is annular. In the length direction 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 in the width direction 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 component, 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.

[0470] In addition, when the first wall 110 has four first poles 12, with two first poles 12 spaced apart along the width of the first wall 110 to form a group, with a total of two groups spaced apart along the length 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.

[0471] In some embodiments, referring to FIG8 , 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.

[0472] In addition, in some embodiments, Figure 62 is a cross-sectional schematic diagram of the shell assembly provided in some embodiments of the present application. Please refer to Figure 62. 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.

[0473] Figure 63 is a cross-sectional schematic diagram of the shell assembly provided in some embodiments of the present application; Figure 64 is a front projection view of the battery cell provided in some embodiments of the present application; Figure 65 is a cross-sectional view along line EE in Figure 64; Figure 66 is a partial cross-sectional schematic diagram of the battery cell provided in some embodiments of the present application; please refer to Figures 62 to 66. In the embodiments of the present application, the shell 11 specifically includes a shell body 111 and a shell cover 112. The shell body 111 is a square annular structure with one or both ends open. When one end is open, the shell cover 112 is one and is set in the open position. When both ends are open, the shell cover 112 is two and is respectively covered at both open ends of the shell body 111.

[0474] 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, referring to FIG. 62 , the first pole 12 can be provided at one 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 prone to cracking, 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 facilitating the miniaturization of the battery cell 10.

[0475] As an optional solution, referring again to FIG. 62 , 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. Consequently, 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 reduced, making the connection between the housing 111 and the housing cover 112 less susceptible to cracking, thereby improving the reliability of the battery cell 10. Furthermore, the 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 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 reduces cost and weight, and facilitates miniaturization of the battery cell 10.

[0476] 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 conductive portion 22 and the first pole 12 can be welded from the outside of the shell 11. Please refer to Figure 62. 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 problem of 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.

[0477] When the above-mentioned second accommodating groove 12120 is opened on the first pole 12, since the conductive part 22 and the first pole 12 can be welded from the outside of the shell 11 through the notch of the second accommodating groove 12120, please refer to Figure 62. 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 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, thereby improving the connection stability and reliability of the shell body 111 and the shell cover 112 by arranging the first pole 12 at the closed end of the shell body 111.

[0478] Of course, referring to FIG63 , in other embodiments of the present application, all first poles 12 may be provided on the housing cover 112 as required. This facilitates the assembly of the first poles 12 and the housing cover 112, which is not limited in this embodiment.

[0479] In addition, referring to Figures 64 to 66, in the embodiment of the present application, when there are multiple first poles 12 having accommodating portions 121, the first poles 12 may also be disposed on two surfaces on different sides of the housing 11. For example, there may be multiple first poles 12 having accommodating portions 121 disposed on two adjacent surfaces of the housing 11. For another example, there may be multiple first poles 12 having accommodating portions 121 disposed on two opposite surfaces of the housing 11.

[0480] When first poles 12 with accommodating portions 121 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.

[0481] 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.

[0482] Figure 70 is a schematic diagram of the structure of the housing cover 112 provided in some embodiments of the present application. In conjunction with Figures 27 and 70, in the embodiments of the present application, the housing 11 is provided with a pressure relief portion 16. The specific structure of the pressure relief portion 16 is not limited, and for example, it can be 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.

[0483] Optionally, the pressure relief portion 16 and the first pole 12 are 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.

[0484] Please refer to Figures 62 and 70 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 mounting 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 form the pressure relief portion 16 directly 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 this is not limited 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.

[0485] Referring to FIG. 6 and FIG. 8 , optionally, in an embodiment of the present application, along a direction perpendicular to the projection plane Ω, a ratio of a projected area of ​​the weld portion 9 on the projection plane Ω to a projected area of ​​the first wall 110 on the projection plane Ω is within a range of 0.1% to 1%. For example, the ratio of the projected area of ​​the weld portion 9 on the projection plane Ω to the projected area of ​​the first wall 110 on the projection plane Ω is 0.1%, 0.2%, 0.4%, 0.5%, 0.8%, or 1%.

[0486] The projection direction in the above conditions is parallel to the axial direction of the mounting hole 113, then the projection area of ​​the welding portion 9 on the projection surface can be understood as the projection area of ​​the connection area between the conductive portion 22 and the first pole 12 on the projection surface, then the projection area of ​​the welding portion 9 on the projection surface can reflect the area size of the connection area between the conductive portion 22 and the first pole 12, and the projection area of ​​the welding portion 9 on the projection surface meets the above conditions, then to a certain extent, it can reduce the equivalent resistance between the conductive portion 22 and the first pole 12, increase the flow area of ​​the first pole 12, and improve the flow capacity of the first pole 12, thereby helping to improve the charging speed of the battery cell 10 and improve the fast charging performance of the battery cell 10.

[0487] Referring to Figures 6 and 8 , in the embodiment of the present application, the projected area of ​​the second welding surface 220 on the projection plane Ω is greater than or equal to 3% of the total projected area of ​​the first wall 110 on the projection plane Ω; and the projected area of ​​the first welding surface 120 on the projection plane Ω is greater than or equal to 25% of the total projected area of ​​the first wall 110 on the projection plane Ω. Of course, only one of the above two conditions may be met, and this embodiment of the present application is not limited thereto.

[0488] For example, the projection area of ​​the second welding surface 220 on the projection surface Ω accounts for 3%, 3.5%, 4%, 4.4%, 5%, etc. of the total projection area of ​​the first wall 110 on the projection surface Ω; the projection area of ​​the first welding surface 120 on the projection surface Ω accounts for 25%, 25.4%, 25.8%, 26%, 26.5%, etc. of the total projection area of ​​the first wall 110 on the projection surface Ω.

[0489] In the above technical solution, by setting the proportion of the projec...

Claims

1. A battery cell (10), wherein: include: A housing assembly (1) comprises a housing (11) and a first pole (12), wherein the housing (11) has a first wall (110), the first wall (110) is formed with a mounting hole (113), the first pole (12) is arranged in the mounting hole (113), and the first pole (12) comprises a first welding surface (120); A battery cell assembly (2), comprising an active material coating portion (21) and a conductive portion (22) electrically 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) comprises a second welding surface (220) in contact with the first welding surface (120), and a portion of the second welding surface (220) is welded to a portion of the first welding surface (120) via a welding portion (9); Wherein, taking the plane where the cross section of the mounting hole (113) is located as the projection plane (Ω), along the direction perpendicular to the projection plane (Ω), the outer contour of the projection of the second welding surface (220) on the projection plane (Ω) is located within the outer contour range of the projection of the first welding surface (120) on the projection plane (Ω).

2. The battery cell (10) according to claim 1, wherein: The first pole (12) comprises a pole body (12a), a first limiting platform (12b) and a second limiting platform (12c); the pole body (12a) is inserted into the mounting hole (113); the first limiting platform (12b) and the second limiting platform (12c) are arranged at two ends of the pole body (12a) along a direction perpendicular to the projection plane (Ω); the first limiting platform (12b) is limitedly matched to the outer side of the shell (11); and the second limiting platform (12c) is limitedly matched to the inner side of the shell (11); The second limiting platform (12c) is close to the end surface of the battery cell assembly (2) to form the first welding surface (120).

3. The battery cell (10) according to claim 2, wherein: The length dimension (L5) of the pole body (12a) in the first direction (X) is greater than or equal to 1 / 3 of the length dimension (a0) of the first wall (110) in the first direction (X); and / or, The width dimension (L6) of the pole body (12a) in the second direction (Y) is greater than or equal to 1 / 2 of the width dimension (b0) of the first wall (110) in the second direction (Y); and / or, The ratio of the circumference of the pole body (12a) matched with the mounting hole (113) to the circumference of the first wall (110) is within a range of 25% to 40%; and / or, The cross-sectional area of ​​the portion of the pole body (12a) that matches the mounting hole (113) is greater than or equal to 10% of the area of ​​the first wall (110); and / or, Along the axial direction of the mounting hole (113), a ratio of a thickness dimension (t) of the pole body (12a) to a thickness dimension (t0) of the first wall (110) is greater than 1 and less than 1.

5.

4. The battery cell (10) according to claim 2 or 3, wherein: The ratio of the length dimension (L1) of the first limiting platform (12b) in the first direction (X) to the length dimension (a0) of the first wall (110) in the first direction (X) is within the range of 1 / 3 to 1 / 2; and / or, The ratio of the width dimension (L2) of the first limiting platform (12b) in the second direction (Y) to the width dimension (b0) of the first wall (110) in the second direction (Y) is within the range of 1 / 2 to 3 / 4; and / or, The first limiting platform (12b) is columnar, and the ratio of the circumference of the outer periphery of the first limiting platform (12b) to the circumference of the first wall (110) is within a range of 30% to 50%; and / or, The ratio of the cross-sectional area of ​​the first limiting platform (12b) to the area of ​​the first wall (110) is within a range of 9% to 25%; and / or, Along the axial direction of the mounting hole (113), the ratio of the thickness dimension (t1) of the first limiting platform (12b) to the thickness dimension (t0) of the first wall (110) is within the range of 0.6 to 1.

5.

5. The battery cell (10) according to any one of claims 2 to 4, wherein: The ratio of the length dimension (L3) of the second limiting platform (12c) in the first direction (X) to the length dimension (a0) of the first wall (110) in the first direction (X) is within the range of 1 / 3 to 1 / 2; and / or, The ratio of the width dimension (L4) of the second limiting platform (12c) in the second direction (Y) to the width dimension (b0) of the first wall (110) in the second direction (Y) is within the range of 1 / 2 to 3 / 4; and / or, The second limiting platform (12c) is columnar, and the ratio of the circumference of the outer periphery of the second limiting platform (12c) to the circumference of the first wall (110) is within a range of 30% to 50%; and / or, The ratio of the cross-sectional area of ​​the second limiting platform (12c) to the area of ​​the first wall (110) is within a range of 9% to 25%; and / or, Along the axial direction of the mounting hole (113), the ratio of the thickness dimension (t2) of the second limiting platform (12c) to the thickness dimension (t0) of the first wall (110) is within the range of 0.6 to 1.

5.

6. The battery cell (10) according to claim 1, wherein: The conductive part (22) comprises a plurality of pole tabs (2211) connected to the active material coating part (21); the plurality of pole tabs (2211) are gathered at one end close to the active material coating part (21) to form a first gathered part (2212); the plurality of pole tabs (2211) are gathered at one end away from the active material coating part (21) and connected to form a second gathered part (2213); the first gathered part (2212) connects the second gathered part (2213) and the active material coating part (21); and the end face of the second gathered part (2213) on one side close to the first pole (12) forms the second welding surface (220).

7. The battery cell (10) according to claim 6, wherein: Taking the plane where the cross section of the mounting hole (113) is located as the projection plane (Ω), along the direction perpendicular to the projection plane (Ω), at least a portion of the outer contour of the projection of the first gathered portion (2212) on the projection plane (Ω) is located within the range of the outer contour of the projection of the first welding surface (120) on the projection plane (Ω).

8. The battery cell (10) according to claim 1, wherein: The conductive part (22) comprises a plurality of pole tabs (2211) connected to the active material coating part (21), and a transfer plate (222); the plurality of pole tabs (2211) are gathered together at one end close to the active material coating part (21) to form a first gathered part (2212), the plurality of pole tabs (2211) are gathered together at one end away from the active material coating part (21) and connected to form a second gathered part (2213), the first gathered part (2212) connects the second gathered part (2213) and the active material coating part (21), the transfer plate (222) connects the second gathered part (2213) and the first pole (12), and a part of the end surface of the transfer plate (222) close to the first pole (12) forms the second welding surface (220).

9. The battery cell (10) according to claim 8, wherein: Taking the plane where the cross section of the mounting hole (113) is located as the projection plane (Ω), along a direction perpendicular to the projection plane (Ω), at least a portion of the outer contour of the projection of the second gathered portion (2213) on the projection plane (Ω) is located within the outer contour range of the projection of the first welding surface (120) on the projection plane (Ω); and / or, Taking the plane where the cross section of the mounting hole (113) is located as the projection plane (Ω), along the direction perpendicular to the projection plane (Ω), at least a portion of the outer contour of the projection of the first gathered portion (2212) on the projection plane (Ω) is located within the range of the outer contour of the projection of the first welding surface (120) on the projection plane (Ω).

10. The battery cell (10) according to any one of claims 1 to 9, wherein: The first pole (12) is provided with a receiving portion (121), and at least a portion of the conductive portion (22) is received in the receiving portion (121).

11. The battery cell (10) according to claim 10, wherein: The accommodating portion (121) 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); a notch of the first accommodating groove (12110) is formed on the pole inner end face (122); and at least a portion of the conductive portion (22) is accommodated in the first accommodating groove (12110).

12. The battery cell (10) according to claim 11, wherein: The groove wall of the first accommodating groove (12110) has a first recessed groove (12112), and the position where the conductive part (22) is electrically connected to the first pole (12) is at least partially located in the first recessed groove (12112).

13. The battery cell (10) according to claim 11 or 12, 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); and a notch of the first groove (126) is formed on the pole outer end surface (123).

14. The battery cell (10) according to claim 13, wherein: The battery cell (10) further comprises a slot cover (7), wherein the slot cover (7) is arranged on the first pole (12) and covers the slot opening of the first groove (126).

15. The battery cell (10) according to claim 10, wherein: The accommodating portion (121) has a second accommodating groove (12120); the surface of the first pole (12) away from the active material coating portion (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) is connected to the interior of the shell (11) through a first through hole (12130); the conductive portion (22) is passed through the first through hole (12130) and is at least partially accommodated in the second accommodating groove (12120).

16. The battery cell (10) according to claim 15, wherein: The second accommodating groove (12120) has a second sink groove (12122), and the position where the conductive portion (22) is electrically connected to the first pole (12) is at least partially located in the second sink groove (12122).

17. The battery cell (10) according to claim 15 or 16, wherein: The housing assembly (1) further comprises a first cover plate (13), the first cover plate (13) cooperates with the first pole (12) and closes the notch of the second receiving groove (12120), and the first cover plate (13) is electrically connected to the first pole (12).

18. The battery cell (10) according to any one of claims 15 to 17, 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).

19. The battery cell (10) according to any one of claims 10 to 18, 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).

20. The battery cell (10) according to claim 19, wherein: The bracket (3) is provided with a guide portion (32), the guide portion (32) surrounds and forms at least a portion of the avoidance hole (31), and the guide portion (32) at least partially extends to the accommodating portion (121).

21. The battery cell (10) according to claim 19 or 20, 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).

22. The battery cell (10) according to any one of claims 19 to 21, 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).

23. The battery cell (10) according to any one of claims 19 to 22, wherein: Also includes: An internal insulating member (4), the internal insulating member (4) is located inside the shell (11) and wrapped around the active material coating portion (21), and is connected to the bracket (3).

24. The battery cell (10) according to any one of claims 19 to 23, wherein: The housing assembly (1) comprises a plurality of poles, at least one of the poles being the first pole (12).

25. The battery cell (10) according to claim 24, wherein: The shell (11) has a pressure relief portion (16), and the pressure relief portion (16) and the first pole (12) are located on the same side surface of the shell (11); or the pressure relief portion (16) and the first pole are located on two surfaces on different sides of the shell (11).

26. The battery cell (10) according to any one of claims 1 to 25, wherein: The shell (11) is provided with a pressure relief portion (16). The shell (11) comprises a shell body (111) and a shell cover (112). One end of the shell body (111) is open. The shell cover (112) is arranged at the open end of the shell body (111). The pressure relief portion (16) is arranged on the shell cover (112).

27. The battery cell (10) according to any one of claims 1 to 26, wherein: Along a direction perpendicular to the projection plane (Ω), a ratio of a projection area of ​​the welding portion (9) on the projection plane (Ω) to a projection area of ​​the first wall (110) on the projection plane (Ω) is within a range of 0.1% to 1%.

28. The battery cell (10) according to any one of claims 1 to 27, wherein: The projection area of ​​the second welding surface (220) on the projection surface (Ω) is greater than or equal to 3% of the total projection area of ​​the first wall (110) on the projection surface (Ω); and / or, The projection area of ​​the first welding surface (120) on the projection surface (Ω) is greater than or equal to 25% of the total projection area of ​​the first wall (110) on the projection surface (Ω).

29. The battery cell (10) according to any one of claims 1 to 28, wherein: At least two first poles (12) are arranged on the first wall (110).

30. The battery cell (10) according to any one of claims 1 to 28, wherein: The housing (11) has two first walls (110) arranged opposite to each other, and each of the first walls is provided with a first pole.

31. The battery cell (10) according to any one of claims 1 to 28, wherein: The mounting hole (113) comprises a plurality of sub-holes (1131) arranged at intervals, the first pole (12) comprises a plurality of sub-poles (12A) of the same polarity, and the plurality of sub-poles (12A) are arranged in a one-to-one correspondence in the plurality of sub-holes (1131); the battery cell assembly (2) comprises a plurality of active material coating portions (21), the conductive portion (22) comprises a plurality of conductive sub-portions (22A) connected in a one-to-one correspondence with the plurality of active material coating portions (21), and each conductive sub-portion (22A) is electrically connected to a sub-poles (12A) via a welding portion (91); The cross-sectional surface of the mounting hole (113) is taken as a projection surface (Ω), and along a direction perpendicular to the projection surface (Ω), the sum of the projection areas of the plurality of welding sections (91) on the projection surface (Ω) and the projection area of ​​the first wall (110) on the projection surface (Ω) are calculated. The ratio of the projected area on the shadow surface (Ω) is between 0.1% and 1%.

32. The battery cell (10) according to any one of claims 1 to 31, wherein: The outer contour of the projection of the first pole (12) on the projection plane (Ω) is composed of a straight line, or a straight line and an arc.

33. The battery cell (10) according to any one of claims 1 to 32, wherein: The size of the first pole (12) in the first direction (X) is greater than or equal to the size of the first pole (12) 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.

34. The battery cell (10) according to claim 33, wherein: The size of the first pole (12) in the first direction (X) is greater than or equal to three times the size of the first pole (12) in the second direction (Y); and / or, The first direction (X) is the length direction of the first wall (110), and the second direction (Y) is the width direction of the first wall (110).

35. A battery (100), wherein: It comprises a battery cell (10) according to any one of claims 1 to 34.

36. An electrical device (1000), wherein: Comprising a battery (100) according to claim 35.

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