Battery cells, batteries and electrical devices

Abstract

The present invention relates to a battery cell, a battery, and an electric device, which belong to the technical field of batteries. The battery cell includes a casing assembly and a battery core assembly. The casing assembly includes a casing and a first pole mounted in the casing. The battery core assembly includes an active material coated portion and a conductive portion. The active material coated portion is housed in the casing. The conductive portion is used to electrically connect the active material coated portion and the first pole. The first pole is provided with a housing, and at least a portion of the conductive portion is housed in the housing. By housing at least a portion of the conductive portion in the housing, this battery cell reduces the space occupied by the conductive portion within the casing, which is advantageous for improving the energy density of the battery cell.

Description

[Technical Field]

[0001] This application relates to the technical field of batteries, and more particularly to battery cells, batteries, and electrical devices. [Background technology]

[0002] In recent years, new energy vehicles have made great strides, and in the field of electric vehicles, batteries play an irreplaceable and important role as the power source for electric vehicles. Batteries typically contain multiple battery cells, and currently, it is difficult to improve the energy density of battery cells, making it difficult to extend the vehicle's driving range. Summary of the Invention

[0003] Embodiments of the present application provide battery cells, batteries, and electrical devices that are advantageous for improving the energy density of battery cells.

[0004] In a first aspect, an embodiment of the present application provides a battery cell including a casing assembly and a battery core assembly, wherein the casing assembly includes a casing and a first pole mounted in the casing, and the battery core assembly includes an active material application portion and a conductive portion, the active material application portion is housed in the casing, and the conductive portion is used to electrically connect the active material application portion and the first pole, wherein the first pole has a housing portion installed thereon, and at least a portion of the conductive portion is housed in the housing portion.

[0005] In the above technical solution, by providing a receiving section on the first pole, the weight of the first pole can be reduced to some extent, improving the weight energy density of the battery cell and the battery. Meanwhile, by accommodating at least a portion of the conductive section within the receiving section, it occupies space within the first pole, reducing the space occupied by the conductive section within the casing. For a given casing size, this saves space for a larger active material coated section within the casing, thereby improving the volumetric energy density of the battery cell. At the same time, by accommodating at least a portion of the conductive section within the receiving section, the space occupied by the battery cell itself can be reduced, allowing more battery cells to be accommodated in a given battery volume, further improving the volumetric energy density of the battery. Additionally, by accommodating at least a portion of the conductive section within the receiving section, the redundancy of the conductive section within the casing can be reduced to some extent, reducing the probability of short-circuiting between the conductive section and the active material coated section, reducing the probability of short-circuiting of the electrode assembly, and further improving the operational reliability and stability of the battery cell and the battery.

[0006] In some embodiments, the accommodating portion has a first accommodating groove, the surface of the first pole facing the active material coated portion is the pole inner end face, the groove opening of the first accommodating groove is formed in the pole inner end face, and at least a portion of the conductive portion is accommodated in the first accommodating groove.

[0007] In the above technical solution, by forming a first accommodating groove in the first pole, the weight of the first pole can be reduced to a certain extent, thereby improving the weight-to-energy density of the battery cell and battery. Meanwhile, the groove opening of the first accommodating groove is formed on the inner end surface of the pole, which is the surface closest to the active material coating portion of the first pole, so the first accommodating groove opens toward the active material coating portion, thereby making it easier for the conductive portion to extend into the first accommodating groove and improving assembly efficiency. At the same time, because the first accommodating groove faces the active material coating portion, the first accommodating groove also functions as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated in the casing. This allows the battery cell to prolong its service life when there is a larger amount of electrolyte, as electrolyte is consumed during the charging and discharging process of the battery cell. Furthermore, because the first accommodating groove faces the active material coating portion, the first accommodating groove also functions as a structure for accommodating and buffering gas generated inside the electrode assembly, reducing expansion of the battery cell and improving the reliability and stability of the battery cell. Furthermore, because the first accommodating groove is located inside the electrode post, external foreign objects and impurities are less likely to enter the first accommodating groove, reducing the impact of external foreign objects and impurities on the electrode assembly, ensuring the operational stability and reliability of the electrode assembly and further improving the stability and reliability of the battery cell and battery.

[0008] In some embodiments, the casing has a mounting hole, the first pole is mounted in the mounting hole, and the depth H1 of the first accommodating groove along the axial direction of the first pole is equal to or greater than the minimum distance H2 from the inner end face of the pole to the mounting hole.

[0009] In the above technical solution, the depth of the first receiving groove in the axial direction of the first pole is equal to or greater than the minimum distance from the inner end face of the pole to the mounting hole, thereby fully utilizing the volume of the first pole and allowing the first receiving groove to have a relatively large depth, which is advantageous for accommodating more conductive parts and further reducing the space occupied by the conductive parts in the casing, thereby further improving the energy density of the battery cell and further reducing the redundancy of the conductive parts in the casing. At the same time, the relatively large depth of the first receiving groove can also accommodate gas generated in the electrode assembly, ensuring the reliability and stability of the battery cell, and can accommodate more electrolyte, thereby ensuring the service life of the battery cell.

[0010] In some embodiments, the first pole includes a first end wall and a first side wall, the first end wall being located on a side of the first side wall away from the active material application portion, the first end wall and the first side wall surrounding each other forming a first accommodating groove, and the electrical connection position between the conductive portion and the first pole being located on the first end wall and / or the first side wall.

[0011] In the above technical solution, by locating the position where the conductive portion is electrically connected to the first pole on at least one of the first end wall and the first side wall, the first receiving groove not only accommodates at least a portion of the conductive portion but also realizes the electrical connection with the conductive portion, thereby simplifying the structure of the first pole, facilitating processing of the first pole, simplifying the structure of the conductive portion, reducing redundancy of the conductive portion, and reducing the cost of the conductive portion. Furthermore, by utilizing the groove wall of the first receiving groove to realize the electrical connection with the conductive portion, a relatively large electrical connection area between the conductive portion and the first pole can be provided, which not only reduces the difficulty of electrical connection but also improves the reliability and stability of the electrical connection, thereby further improving the performance of the battery cell.

[0012] In some embodiments, the first end wall has a first recessed groove, and at least a portion of the electrical connection location between the conductive portion and the first end wall is located within the first recessed groove.

[0013] In the above technical solution, by installing the first sunken groove in the first end wall, the first sunken groove can be used to achieve pre-positioning of the conductive part, which is advantageous for accurately aligning the position to achieve electrical connection and improving production efficiency; on the other hand, by installing the first sunken groove in the first end wall, the local thickness of the first end wall can be partially thinned, which not only facilitates electrical connection by welding, but also reduces the weight of the first pole and is advantageous for improving the weight-energy density of the battery cell.

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

[0015] In the above technical solution, by providing the first recess in the first pole, the weight of the first pole can be further reduced and the weight energy density of the battery cells and the battery can be improved. Meanwhile, the first recess is located on the outside of the first pole and can be used to accommodate or mount structural components electrically connected to each battery cell in the battery, making full use of the space within the first pole and improving the space utilization rate and volumetric energy density of the battery. Furthermore, the first pole has an active material application portion that is simultaneously shared by the first accommodating groove and the first recessed groove, the first recessed groove is located on the side away from the first accommodating groove, and the first recessed groove is open in the direction away from the first accommodating groove. This is advantageous in that the conductive portion can be electrically connected to the groove wall of the first accommodating groove from the outside of the first pole via the first recessed groove, for example, making it easy to externally weld the first pole and the conductive portion via the first recessed groove, which also facilitates processing and manufacturing of the battery cell and reduces processing and manufacturing costs.

[0016] In some embodiments, the casing assembly further includes a groove cover provided on the pole and sealingly capping the groove opening of the first groove.

[0017] In the above technical solution, the installation of the groove cover facilitates the electrical connection between adjacent battery cells within the battery, and the electrical connection between the battery cells is separated by the first groove from the electrical connection between the conductive part and the first pole, reducing interference between the two and further improving the stability and reliability of the battery cells. At the same time, the groove cover prevents foreign objects from entering the first groove, reducing interference between external foreign objects and the battery core assembly, further improving the reliability and stability of the battery cells.

[0018] In some embodiments, the active material application portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab sheets, the plurality of tab sheets gather at a position close to the current collector to form a first converging portion, and the plurality of tab sheets gather at a position away from the current collector to be connected to form a second converging portion, the first converging portion connects the second converging portion and the active material application portion, and at least a portion of the second converging portion is received in the first receiving groove.

[0019] In the above technical solution, the tab portion includes a second converging portion formed by connecting multiple tab sheets together. By accommodating at least a portion of the second converging portion in the first accommodating groove, the conductive portion can be easily connected to the first pole, the space of the first pole can be utilized to the maximum extent, and the volumetric energy density of the battery cell can be improved.

[0020] In some embodiments, at least a portion of the first converging portion is received in the first receiving groove.

[0021] In the above technical solution, at least a portion of the first converging portion of the tab portion and at least a portion of the second converging portion are both accommodated in the first accommodating groove, thereby making better use of the space within the first pole, further reducing the space occupied by the tab portion within the casing, and improving the volumetric energy density of the battery cell.

[0022] In some embodiments, the conductive portion further includes an adapter sheet connected to the second converging portion, the conductive portion being electrically connected to the first pole via the adapter sheet, and at least a portion of the adapter sheet being accommodated in the first accommodating groove.

[0023] In the above technical solution, on the one hand, by accommodating at least a portion of the second converging portion and at least a portion of the adapter sheet in the first accommodating groove, the space within the first pole can be more fully utilized, further reducing the space occupied by the conductive part within the casing and further improving the volumetric energy density of the battery cell. On the other hand, by using the adapter sheet to achieve an indirect electrical connection between the second converging portion and the first pole, the adapter sheet can be welded to the first pole using a portion that avoids the second converging portion. This improves the reliability of the weld between the adapter sheet and the first pole, reduces the risk of weld cracking, and further improves the reliability and stability of the battery cell. At the same time, by electrically connecting the first pole and the tab portion via the adapter sheet, the structure of the tab portion can be simplified.

[0024] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion including a plurality of tab sheets electrically connected to the current collector, and an adapter sheet, the plurality of tab sheets gathering at a position close to the current collector to form a first converging portion, and the plurality of tab sheets gathering at a position away from the current collector to be connected to form a second converging portion, the adapter sheet being electrically connected to the second converging portion, and at least a portion of the adapter sheet being accommodated in the first accommodating groove and electrically connected to the first pole.

[0025] In the above technical solution, on the one hand, by using an adapter sheet to realize an indirect electrical connection between the second converging portion and the first electrode post, the adapter sheet can be welded to the first electrode post using a portion that avoids the second converging portion. This ensures reliable welding between the adapter sheet and the electrode post, reducing the risk of weld cracking and further improving the reliability and stability of the battery cell. At the same time, the electrical connection between the first electrode post and the tab portion via the adapter sheet also simplifies the structure of the tab portion. On the other hand, because at least a portion of the adapter sheet is accommodated in the first accommodating groove, the adapter sheet can occupy space within the first electrode post. This reduces the space occupied by the adapter sheet within the casing, allowing a larger active material coating portion to be accommodated, improving the volumetric energy density of the battery cell, and reducing the probability of a short circuit between the adapter sheet and the active material coating portion. This reduces the risk of a short circuit in the electrode assembly and improves the stability and reliability of the battery cell.

[0026] In some embodiments, the accommodating portion has a second accommodating groove, the surface of the first pole facing away from the active material application portion is the pole outer end face, the groove opening of the second accommodating groove is formed on the pole outer end face, the second accommodating groove communicates with the inside of the casing via the first through hole, and the conductive portion is drilled in the first through hole and at least a portion of the conductive portion is accommodated in the second accommodating groove.

[0027] In the above technical solution, by providing a second accommodating groove in the first pole, the weight of the first pole can be reduced to some extent, improving the weight-to-energy density of the battery cell and battery. Meanwhile, the second accommodating groove has a groove opening on the outer end surface of the pole, which is on one side away from the active material-coated portion of the first pole. This allows the second accommodating groove to open in a direction away from the active material-coated portion. Thus, when at least a portion of the conductive portion is accommodated in the second accommodating groove, the groove opening of the second accommodating groove can be used to easily accommodate and organize the conductive portion or to electrically connect the conductive portion to the first pole, further reducing the difficulty of battery cell manufacturing and improving battery cell production efficiency. At the same time, because the second accommodating groove is connected to the casing via the first through-hole, the second accommodating groove also functions as a buffer and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated in the casing. Since the electrolyte is consumed during the charge and discharge process of the battery cell, a larger amount of electrolyte can extend the service life of the battery cell. Furthermore, because the second accommodating groove is connected to the casing via the first through-hole, the second accommodating groove also functions as a structure for accommodating and buffering gas generated inside the electrode assembly, reducing expansion of the battery cell and improving the reliability and stability of the battery cell.

[0028] In some embodiments, the electrical connection position between the conductive portion and the first pole is located on the wall of the first through-hole formed in the first pole.

[0029] In the above technical solution, when the electrical connection position between the conductive part and the first electrode post is installed on the wall of the first through-hole, the electrical connection between the conductive part and the first electrode post can be performed through the second receiving groove, and at the same time, the electrical connection position between the conductive part and the first electrode post can seal the first through-hole, saving sealing costs and reducing electrolyte leakage.

[0030] In some embodiments, the first electrode post includes a second end wall and a second side wall, the second end wall being located on a side of the second side wall that is close to the active material application portion, the second end wall and the second side wall surrounding each other forming a second accommodating groove, a first through hole being provided in the second end wall, and an electrical connection position between the conductive portion and the first electrode post being located in the second end wall and / or the second side wall.

[0031] In the above technical solution, by locating the electrical connection position between the conductive part and the first pole on at least one of the second end wall and the second side wall, the second receiving groove not only serves to receive at least a portion of the conductive part, but also has a groove wall of the second receiving groove serve to realize electrical connection with the conductive part, thereby simplifying the structure of the first pole and facilitating processing of the first pole.Furthermore, since the first through-hole is opened in the second end wall, it is easy for the conductive part to extend into the second receiving groove through the first through-hole, simplifying the structure of the conductive part, reducing the redundancy of the conductive part, and reducing the cost of the conductive part. In addition, the opening direction of the groove opening of the second accommodating groove can facilitate the electrical connection between the conductive part and the groove wall of the second accommodating groove through the groove opening of the second accommodating groove, reducing the difficulty of the electrical connection. Furthermore, by realizing the electrical connection with the conductive part using the groove wall of the second accommodating groove, the electrical connection area between the conductive part and the first pole can be relatively increased, improving the reliability and stability of the electrical connection and further improving the performance of the battery cell.

[0032] In some embodiments, the second end wall has a second recessed groove, and at least a portion of the electrical connection location between the conductive portion and the second end wall is located within the second recessed groove.

[0033] In the above technical solution, by installing a second recessed groove on the second end wall, the second recessed groove can be used to realize pre-positioning of the conductive part, allowing for accurate alignment and electrical connection, thereby improving production efficiency.

[0034] In some embodiments, the casing has a mounting hole, the first pole is mounted in the mounting hole, and the depth H3 of the second accommodating groove along the axial direction of the first pole is equal to or greater than the minimum distance H4 from the outer end face of the pole to the mounting hole.

[0035] In the above technical solution, the depth of the second accommodating groove in the axial direction of the first pole is equal to or greater than the minimum distance from the outer end face of the pole to the mounting hole, thereby making full use of the volume of the first pole and allowing the second accommodating groove to have a relatively large depth, which is advantageous for accommodating more conductive parts and further reducing the space occupied by the conductive parts in the casing, thereby further improving the energy density of the battery cell and further reducing the redundancy of the conductive parts in the casing. At the same time, the relatively large depth of the second accommodating groove can also accommodate gas generated in the electrode assembly, improving the reliability and stability of the battery cell, and can accommodate more electrolyte, thereby improving the service life of the battery cell.

[0036] In some embodiments, the casing assembly further includes a first cover plate, which is fitted with the first pole and seals the groove opening of the second receiving groove, and the first cover plate is electrically connected to the first pole.

[0037] In the above technical solution, by installing the first cover plate to seal the opening of the second accommodating groove, it is possible to prevent the electrolyte in the casing from leaking from the opening of the second accommodating groove. Furthermore, the first cover plate seals the opening of the second accommodating groove and is electrically connected to the first pole. This makes it easy to use the first cover plate to achieve an indirect electrical connection between the first pole and the bus member of the battery, which is advantageous for increasing the connection area of ​​the electrical connection point and reducing the resistance of the electrical connection point.

[0038] In some embodiments, the first cover plate includes a first conductive member and a second conductive member made of different materials, the first conductive member being fitted to and electrically connected with the first pole, and the second conductive member being fitted to and electrically connected with the first conductive member.

[0039] In the above technical solution, the first cover plate is installed in a composite form, and the first conductive member is installed with the same material as the first pole, thereby facilitating the electrical connection between the first conductive member and the first pole; and since the second conductive member is made of a different material from the first conductive member, the second conductive member is used to facilitate the electrical connection with the battery bus member made of a different material from the first pole.

[0040] In some embodiments, the first conductive member has a second groove, the second conductive member is fitted into the second groove, and the groove opening of the second groove is formed on a surface of the first conductive member facing away from the second receiving groove so that the second conductive member is exposed from the groove opening of the second groove.

[0041] In the above technical solution, the second conductive member is fitted into the first conductive member, which reduces the difficulty of assembling the first and second conductive members and improves the stability and convenience of the first and second conductive members when they are fitted together. It also reduces the thickness of the first cover plate, reducing the space occupied by the first cover plate and improving the space utilization rate of the battery cell. Meanwhile, the second conductive member can be exposed from the surface of the first conductive member facing away from the second receiving groove through the opening of the second groove, which is advantageous for achieving electrical connection between the second conductive member and battery bus members other than the first pole. Furthermore, because the opening of the second groove is formed on the surface of the first conductive member facing away from the second receiving groove, the first conductive member is isolated between the second receiving groove and the second conductive member, which prevents contact between the electrolyte in the second groove and the second conductive member and reduces electrolyte leakage.

[0042] In some embodiments, the first cover plate is fitted into the groove opening of the second receiving groove.

[0043] In the above technical solution, by fitting the first cover plate into the second accommodating groove, the difficulty of assembling the first cover plate and the first pole can be reduced, the assembly stability and connection reliability and convenience of the first cover plate and the first pole can be improved, and the space occupied by the first cover plate other than the first pole can be reduced.In addition, because the first cover plate is fitted into the groove opening of the second accommodating groove, there can be a relatively sufficient space in the second accommodating groove to accommodate the conductive part.

[0044] In some embodiments, the wall surface on which the groove opening of the second accommodating groove of the first pole post is formed is a guide slope, and the guide slope is used to guide the engagement between the first cover plate and the groove opening of the second accommodating groove.

[0045] In the above technical solution, by processing the wall surface of the groove opening of the second accommodating groove into a sloped surface with a guide function, the difficulty of assembling the first cover plate and the second accommodating groove can be reduced, and the assembly efficiency of the first cover plate and the second accommodating groove can be improved.

[0046] In some embodiments, the second receiving groove includes a first groove step and a second groove step on a side of the first groove step that is adjacent to the outer end surface of the pole post, the cross-sectional area of ​​the second groove step being larger than the cross-sectional area of ​​the first groove step so as to form a stepped surface between the first groove step and the second groove step, and the first cover plate is fitted into the second groove step and supported by the stepped surface.

[0047] In the above technical solution, by configuring the second accommodating groove in the form of a stepped groove, the first cover plate can be stably fitted into the groove opening position of the second accommodating groove, improving the connection stability between the first cover plate and the first pole; and by limiting the groove depth of the first groove step, a relatively sufficient space can be provided in the second accommodating groove to accommodate the conductive part.

[0048] In some embodiments, the first cover plate includes a stress relief groove located in a peripheral region of the first cover plate.

[0049] In the above technical solution, by installing a stress relief groove in the first cover plate, the stress generated in the first cover plate during its own processing or during the electrical connection process between the first cover plate and the first pole can be released, thereby improving the problem of deformation or damage caused by stress on the first cover plate.

[0050] In some embodiments, the casing assembly further includes a second cover plate, which covers the outside of the conductive portion disposed in the first through hole and the second receiving groove.

[0051] In the above technical solution, when the electrolyte enters the second accommodating groove through the first through-hole, the second cover plate can solve the problem of the electrolyte in that portion overflowing from the first pole, thereby improving the reliability of the battery cell.

[0052] In some embodiments, the first pole includes a first pole portion and a second pole portion made of different materials and electrically connected to each other, the second pole portion being located on the side of the first pole portion away from the active material application portion, the accommodating portion being mounted on the first pole portion or on the first pole portion and the second pole portion, and the conductive portion being electrically connected to the first pole portion.

[0053] In the above technical solution, the first pole is configured in a composite form using a combination of different materials, utilizing the fitting and electrical connection between the first pole part located on the inside and the conductive part, and utilizing the electrical connection between the second pole part located on the outside and the bus parts of the battery, etc., which is advantageous for realizing the assembly and electrical connection between the first pole and related parts, reduces mutual interference between the electrical connection position between the pole and the conductive part and the electrical connection position between the pole and the bus parts of the battery, and improves the reliability and stability of the battery cell.

[0054] In some embodiments, the active material application portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion electrically connected to the current collector, the tab portion includes a plurality of tab sheets, the plurality of tab sheets gather at a position close to the current collector to form a first converging portion, and the plurality of tab sheets gather at a position away from the current collector to be connected to form a second converging portion, the first converging portion connects the second converging portion and the active material application portion, and at least a portion of the second converging portion is received in the second receiving groove.

[0055] In the above technical solution, the tab portion includes a second converging portion formed by connecting a plurality of tab sheets together, so that at least a portion of the second converging portion is accommodated in the second accommodating groove, which facilitates assembly of the conductive portion and the first pole.

[0056] In some embodiments, the accommodating portion further has a third accommodating groove, the surface of the first pole facing the active material application portion is the pole inner end face, the third accommodating groove is located on the side of the second accommodating groove that is close to the active material application portion, and the groove opening of the third accommodating groove is formed on the pole inner end face, the third accommodating groove and the second accommodating groove are connected via the first through hole, and at least a portion of the first converging portion is accommodated in the third accommodating groove.

[0057] In the above technical solution, at least a portion of the first converging portion of the tab portion is accommodated in the third accommodating groove, and at least a portion of the second converging portion is accommodated in the second accommodating groove, thereby making better use of the space within the first pole post.

[0058] In some embodiments, the conductive portion further includes an adapter sheet connected to the second converging portion, the conductive portion being electrically connected to the first pole via the adapter sheet, and at least a portion of the adapter sheet being accommodated in the second accommodating groove.

[0059] In the above technical solution, by accommodating at least a portion of the second converging portion and at least a portion of the adapter sheet in the second accommodating groove, the space within the first pole can be more fully utilized, further reducing the space occupied by the conductive part within the casing and further improving the volumetric energy density of the battery cell. On the other hand, by using the adapter sheet to achieve an indirect electrical connection between the second converging portion and the first pole, the adapter sheet can be welded to the first pole using a portion that avoids the second converging portion. This ensures reliable welding between the adapter sheet and the first pole, reducing the risk of weld cracking and further improving the reliability and stability of the battery cell. At the same time, by using the adapter sheet to achieve the electrical connection between the tab portion and the first pole, the structure of the tab portion can be simplified.

[0060] In some embodiments, the active material coating portion includes a current collector and an active material layer provided on the current collector, the conductive portion includes a tab portion including a plurality of tab sheets electrically connected to the current collector, and an adapter sheet, the plurality of tab sheets gathering at a position close to the current collector to form a first converging portion, and the plurality of tab sheets gathering at a position away from the current collector to be connected to form a second converging portion, the adapter sheet being electrically connected to the second converging portion, and at least a portion of the adapter sheet being accommodated in the second accommodating groove and electrically connected to the first pole.

[0061] In the above technical solution, the conductive part includes an adapter sheet that realizes the electrical connection between the tab part and the first pole, thereby simplifying the structure of the tab part, and by accommodating at least a portion of the adapter sheet in the second accommodating groove, the adapter sheet can occupy space within the first pole, thereby reducing the space occupied by the adapter sheet within the casing, accommodating a larger-sized active material application part, improving the energy density of the battery cell, and reducing the probability of short-circuiting between the adapter sheet and the active material application part.

[0062] In some embodiments, the accommodating portion has a fourth accommodating groove, the surface of the first pole facing away from the active material application portion is the pole outer end face, the groove opening of the fourth accommodating groove is formed on the pole outer end face, the fourth accommodating groove is connected to the inside of the casing via the second through hole, the conductive portion is formed through the second through hole, and the electrical connection position between the conductive portion and the first pole is located on the hole wall of the second through hole formed in the first pole.

[0063] In the above technical solution, the provision of the fourth receiving groove can easily realize the electrical connection between the conductive part and the hole wall of the second through-hole, and in some cases, the electrical connection between the conductive part and the first pole can be used to achieve the sealing of the second through-hole.

[0064] In some embodiments, the battery cell further includes a support disposed within the casing and located on a side of the active material application portion that is close to the first pole, the support having an escape hole for avoiding the conductive portion, and the conductive portion extending through the escape hole on a side of the support that is away from the active material application portion.

[0065] In the above technical solution, by providing an escape hole in the support, the conductive part can be guided and restrained so that it passes through the escape hole and fits into the first pole, which not only simplifies the arrangement of the conductive part, saves material for the conductive part, and reduces costs, but also supports and guides the fit between the conductive part and the first pole through the support, reduces the risk of short-circuiting between the conductive part and the active material application part, and further improves the reliability of the battery cell.

[0066] In some embodiments, the support is provided with a guide portion, the guide portion surrounding at least a portion that defines the relief hole, and the guide portion extending at least partially into the receiving portion.

[0067] In the above technical solution, the support has a guide portion that extends at least partially into the receiving portion and is formed to surround at least a portion of the escape hole via the guide portion, so that at least a portion of the conductive portion can be easily accommodated in the receiving portion, improving the assembly efficiency of the conductive portion. At the same time, the installation of the guide portion makes the fit between the support and the pole, and between the support and the conductive portion, tighter and more reliable, making the structure of the battery cell more compact and further favorable for improving the energy density of the battery cell.

[0068] In some embodiments, the support is provided with a third recess, and at least a portion of the first pole post located in the casing is received in the third recess.

[0069] In the above technical solution, the third groove is provided on the support to accommodate at least a portion of the first pole located within the casing. This is advantageous in reducing the space occupied by the support within the casing, and is also advantageous in improving the stability and reliability of the first pole, ensuring the reliability and stability of the electrical connection between the first pole and the battery core assembly, and improving the reliability and stability of the charging and discharging operations of the battery cell.

[0070] In some embodiments, the relief hole includes a first hole section and a second hole section, the second hole section being located on a side of the first hole section that is closer to the active material-coated portion, and the cross-sectional area of ​​the second hole section gradually increases in a direction away from the first hole section. The active material-coated portion includes a current collector and an active material layer disposed on the current collector. The conductive portion is electrically connected to the current collector and includes a tab portion, the tab portion including a plurality of tab sheets, the plurality of tab sheets coming together at a position closer to the current collector to form a first converging portion, and the plurality of tab sheets coming together at a position away from the current collector to form a second converging portion. The first converging portion connects the second converging portion and the active material-coated portion, at least a portion of the first converging portion being received within the second hole section, and the second converging portion being drilled through the first hole section.

[0071] In the above technical solution, the escape hole is configured to include a second hole section that gradually widens toward the active material application section, making it easier for the second hole section to accommodate more of the first converging section, improving the compactness of the fit between the support and the battery core assembly, reducing the overall volume of the battery cells, allowing the battery to accommodate more battery cells, and improving the volumetric energy density of the battery.

[0072] In some embodiments, the support is a unitary structure, or the support is a separate structure including a removable first support and a second support, and the relief hole is defined between the first support and the second support.

[0073] In the above technical solution, if the support has an integral structure, the support can be easily processed, its reliability is relatively good, and the assembly of the support and the casing assembly is easy, improving assembly efficiency and fitting stability. If the support has a separate structure, an escape hole is defined by the engagement of the first support and the second support, and when assembling the support and the battery core assembly, there is no need to pass the conductive part from one end to the other through the escape hole. Instead, the first support and the second support can be combined at the position of the conductive part to sandwich the conductive part, so that the escape hole surrounds the conductive part, making it easy to assemble the support and the battery core assembly and improving assembly efficiency.

[0074] In some embodiments, the battery cell further includes an inner insulating member disposed within the casing, enveloping the outside of the active material coating portion, and connected to the support.

[0075] In the above technical solution, by wrapping the inner insulating member around the outside of the active material application portion, the reliability of the insulation between the active material application portion and the casing is improved, corrosion of the casing due to contact between the active material application portion and the casing is reduced or prevented, and the problem of electrolyte leakage due to casing corrosion is reduced, thereby improving the reliability of the battery cell. Meanwhile, by connecting the inner insulating member to the support, the difficulty of fixing the inner insulating member is reduced, and the reliability of the inner insulating member wrapping around the outside of the active material application portion is improved.

[0076] In some embodiments, the casing assembly includes a plurality of pole posts, and at least one pole post is a first pole post.

[0077] In the above technical solution, at least one of all the poles of the casing assembly is a first pole, so that the entire battery cell may have a first pole partly or entirely having a receiving portion, which allows for flexible selection and combination according to actual needs such as energy density and cost, thereby improving the applicability of the battery cell.

[0078] In some embodiments, the casing has a pressure relief portion, and the pressure relief portion and the pole are located on the same surface of the casing, or the pressure relief portion and the pole are located on two surfaces on different sides of the casing.

[0079] In the above technical solution, if the electrode post and the pressure relief part are installed on the same side, processing and assembly are facilitated; if the electrode post and the pressure relief part are installed on different sides, space can be saved, the volume of the electrode post can be increased, and the adverse effect on the electrode post when the pressure relief part releases pressure can be reduced.

[0080] In some embodiments, the casing has a pressure relief portion, the casing includes a casing body and a casing cover, one end of the casing body is open, the casing cover is provided at the open end of the casing body, and the pressure relief portion is provided at the casing cover.

[0081] In the above technical solution, the pressure relief part is easy to process and has high pressure relief reliability.

[0082] In a second aspect, embodiments of the present application further provide a battery comprising the battery cell described above.

[0083] In the above technical solution, the battery cell is installed in the battery, and a receiving portion is installed on the first pole of the battery cell, thereby reducing the weight of the first pole to a certain extent and improving the weight energy density of the battery cell and the battery. On the other hand, by accommodating at least a portion of the conductive portion in the receiving portion, it occupies space within the first pole, which is advantageous to improving the volumetric energy density of the battery cell, or by reducing the space occupied by the battery cells themselves, more battery cells can be accommodated in a battery of the same volume, which is advantageous to improving the volumetric energy density of the battery. In addition, by accommodating at least a portion of the conductive portion in the receiving portion, it is possible to reduce the redundancy of the conductive portion within the casing to a certain extent and reduce the probability of short-circuiting between the conductive portion and the active material-coated portion, which further improves the operational reliability and stability of the battery cell and the battery.

[0084] In a third aspect, embodiments of the present application further provide an electrical device comprising the battery described above.

[0085] In the above technical solution, the battery is installed in the electrical device, which can increase the energy density of the battery, which is beneficial to extending the service life of the electrical device, and can also improve the operational reliability and stability of the battery, which can improve the operational reliability and stability of the electrical device. [Brief explanation of the drawings]

[0086] In order to more clearly explain the technical solutions of the embodiments of the present application, the drawings used in the embodiments will be briefly introduced below. However, the following drawings only show some embodiments of the present application, therefore, It should be understood that they should not be considered as limiting the scope, and those skilled in the art can derive other related drawings based on these drawings without creative work. [Figure 1] 1 is a structural schematic diagram of a vehicle provided in accordance with some embodiments of the present application. [Figure 2] 1 is an exploded view of a battery structure provided in accordance with some embodiments of the present application. [Figure 3] 1 is a structural schematic diagram of a battery cell provided by some embodiments of the present application; [Figure 4] FIG. 1 is an orthographic view of a battery cell provided in accordance with some embodiments of the present application. [Figure 5] FIG. 5 is a cross-sectional view taken along the line AA in FIG. [Figure 6] 1 is a structural schematic diagram of a battery cell provided by some embodiments of the present application; [Figure 7] 1 is an assembly diagram of a second pole provided in accordance with some embodiments of the present application, a battery core assembly, and a casing. [Figure 8] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 9] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 10] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 11] 1 is a schematic cross-sectional view of a battery core assembly provided in accordance with some embodiments of the present application. [Figure 12] 1 is a diagram illustrating a convergence scheme for multiple types of tabs in a battery core assembly provided by some embodiments of the present application. [Figure 13] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 14] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 15] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 16] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 17] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 18] FIG. 4 is an enlarged view of a portion B in FIG. 3. [Figure 19]1A-1C are orthographic views of a plurality of first polar pillars provided by some embodiments of the present application. [Figure 20] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 21] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 22] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 23] 1 is an exploded view of a battery cell structure provided in accordance with some embodiments of the present application. [Figure 24] 1 is a schematic cross-sectional view of a casing assembly provided in accordance with some embodiments of the present application. [Figure 25] FIG. 25 is an exploded structural view of the casing assembly shown in FIG. 24. [Figure 26] FIG. 26 is an exploded view of the first cover plate shown in FIG. 25. [Figure 27] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 28] FIG. 28 is an exploded view of the structure of the battery cell shown in FIG. 27. [Figure 29] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 30] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 31] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 32] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 33] 1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 34] 1 is a schematic diagram of a battery core assembly and a support mating provided by some embodiments of the present application. [Figure 35] FIG. 35 is a cross-sectional view taken along line CC in FIG. [Figure 36]1 is a structural schematic diagram of an integral support provided by some embodiments of the present application. [Figure 37] 1 is a structural schematic diagram of a separate support provided by some embodiments of the present application. [Figure 38] 1 is a schematic cross-sectional view of a battery core assembly and support provided by some embodiments of the present application. [Figure 39] 1 is an exploded structural view of a battery core assembly, a support, and a casing assembly provided in accordance with some embodiments of the present application. [Figure 40] 1 is an exploded view of the structure of a first pole, a casing, and a seal pad provided in some embodiments of the present application. FIG. [Figure 41] FIG. 41 is an assembly diagram of the first pole, casing, and seal pad shown in FIG. 40. [Figure 42] 1 is a structural schematic diagram of a first pole pillar provided by some embodiments of the present application; [Figure 43] 1 is an assembly diagram of a first pole, a casing, and a seal pad provided in accordance with some embodiments of the present application. [Figure 44] FIG. 44 is an exploded view of the structure of the first pole pillar shown in FIG. 43. [Figure 45] FIG. 1 is an orthographic view of a battery cell provided in accordance with some embodiments of the present application. [Figure 46] FIG. 1 is an orthographic view of a battery cell provided in accordance with some embodiments of the present application. [Figure 47] FIG. 47 is a cross-sectional view taken along line DD in FIG. 46. [Figure 48] 1 is a cross-sectional schematic view of a casing assembly provided in accordance with some embodiments of the present application. [Figure 49] 1 is a cross-sectional schematic view of a casing assembly provided in accordance with some embodiments of the present application. [Figure 50] FIG. 1 is an orthographic view of a battery cell provided in accordance with some embodiments of the present application. [Figure 51] FIG. 51 is a cross-sectional view taken along line EE in FIG. 50. [Figure 52]1 is a schematic cross-sectional view of a battery cell provided in accordance with some embodiments of the present application. [Figure 53] 1 is a structural schematic diagram of a casing cover provided by some embodiments of the present application;

[0087] symbol: Electric device 1000, battery 100, controller 200, motor 300, First direction Z, second direction X, third direction Y, the axial direction R of the first pole; Battery cell 10, case 20, first case 201, second case 202, Casing assembly 1, Casing 11, first wall surface 110, casing body 111, casing cover 112, mounting hole 113, First pole 12, Receiving section 121, a first receiving groove 12110, a first end wall 12111, a first recessed groove 12112, a first side wall 12113, a second receiving groove 12120, a second end wall 12121, a second recessed groove 12122, a second side wall 12123, a first groove step 12124, a second groove step 12125, a guide slope 12126, a step surface 12127, A first through hole 12130, a third receiving groove 12140, a fourth receiving groove 12150, A second through-hole 12160, a third through-hole 12170, Pole column inner end surface 122, pole column outer end surface 123, First pole portion 124, second pole portion 125, First groove 126, spacing portion 127, Stopper portion 1281, perforation portion 1282, flange portion 1283, First part 1291, second part 1292, a first cover plate 13, a first conductive member 131, a second recessed groove 1311, a second conductive member 132, a stress relief groove 133, A second cover plate 14, a second pole post 15, a pressure release portion 16, a relief groove 18, First seal pad 191, second seal pad 192, Battery core assembly 2, electrode assembly 2a, Active material coating portion 21, current collector 211, active material layer 212, conductive portion 22, Tab portion 221, tab sheet 2211, first converging portion 2212, second converging portion 2213, adapter sheet 222, Support 3, relief hole 31, first hole section 311, second hole section 312, Guide portion 32, first support 33, second support 34, casing guide surface 35, A main body portion 36, an extension portion 37, a third recessed groove 38, a positioning groove 39, Inner insulating member 4, main body 41, connecting portion 42, Sealing member 6, groove cover 7. DETAILED DESCRIPTION OF THE INVENTION

[0088] In order to clarify the objectives, technical solutions and advantages of the embodiments of the present application, the technical solutions of the embodiments of the present application will be clearly described below in conjunction with the drawings of the embodiments of the present application, but it is obvious that the described embodiments are only some of the embodiments of the present application, and do not represent all of the embodiments of the present application. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present application without any creative work also belong to the scope of the claims of the present application.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, and the terms used in the specification of the present application are only for describing specific embodiments and are not intended to limit the present application. The terms "comprise" and "have" and any variations thereof in the specification, claims, and drawings of the present application are intended to cover a non-exclusive inclusion. Terms such as "first," "second," etc. in the specification, claims, and drawings of the present application are used to distinguish between different objects and are not used to describe a particular order or priority.

[0090] In this application, reference to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase in various places in the specification do not necessarily refer to the same embodiment, nor are they mutually exclusive, separate, or alternative embodiments of other embodiments.

[0091] The term "and / or" in this application is merely a relation that describes related objects and indicates that three types of relations can exist. For example, A and / or B can indicate three cases: the presence of only A, the simultaneous presence of A and B, and the presence of only B. In addition, the symbol " / " in this application generally indicates that the related objects before and after it are in an "or" relationship.

[0092] In the embodiments of the present application, the same drawing symbols represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments will be omitted. It should be understood that the dimensions such as thickness, length, and width of various components in the embodiments of the present application shown in the drawings, and the overall dimensions such as thickness, length, and width of the integrated device, are merely illustrative and do not constitute any limitations on the present application.

[0093] The term "plurality" as used herein refers to two or more (including two).

[0094] In this application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc., but the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, rectangular, or have other shapes, etc., but the embodiments of this application are not limited thereto. Battery cells are generally classified into three types depending on the encapsulation method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, but the embodiments of this application are not limited thereto.

[0095] The battery referred to in the embodiments of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may be a battery module or a battery pack. A battery module generally includes multiple battery cells. A battery pack generally includes a case for enclosing one or more battery cells or one or more battery modules. The case can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0096] For example, a battery cell typically includes a casing, a battery core assembly, and an electrolyte, where the casing is used to house the battery core assembly and the electrolyte, and at least one positive electrode post and at least one negative electrode post are provided in the casing. The battery core assembly includes one or more electrode assemblies, and the electrode assemblies are formed by stacking or winding positive electrode pieces, negative electrode pieces, and separator films.

[0097] The positive electrode piece generally includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer being directly or indirectly coated on the positive electrode current collector, the positive electrode current collector not coated with the positive electrode active material layer protruding from the positive electrode current collector coated with the positive electrode active material layer, the positive electrode current collector not coated with the positive electrode active material layer being a positive electrode tab sheet, and multiple positive electrode tab sheets are stacked and electrically connected to the positive electrode post. For example, multiple stacked positive electrode tab sheets can be directly welded to the positive electrode post to form the electrical connection, or the battery core assembly can include a positive electrode adapter sheet, and the multiple stacked positive electrode tab sheets can be welded to one end of the positive electrode adapter sheet and the other end of the positive electrode adapter sheet to electrically connect the positive electrode tab sheet and the positive electrode post.

[0098] The negative electrode piece generally includes 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 without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer coated thereon. The positive electrode current collector without the negative electrode active material layer serves as a negative electrode tab sheet. Multiple negative electrode tab sheets are stacked together and electrically connected to the negative electrode post. For example, the multiple stacked negative electrode tab sheets can be directly welded to the negative electrode post to form the electrical connection. Alternatively, the battery core assembly can include a negative electrode adapter sheet. The multiple stacked negative electrode tab sheets 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 electrically connect the negative electrode tab sheet and the negative electrode post. The material of the separator film is not particularly limited and may be, for example, polypropylene or polyethylene.

[0099] At the same time, battery cells primarily rely on the movement of metal ions between the positive and negative electrodes to function. 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. During charging and discharging, Li+ ions are repeatedly inserted and extracted between the two electrodes. During charging, Li+ ions are extracted from the positive electrode and inserted into the negative electrode through the electrolyte, leaving the negative electrode in a lithium-rich state, and vice versa during discharging.

[0100] In recent years, new energy vehicles have made great strides, and in the field of electric vehicles, batteries play an irreplaceable and important role as the power source for electric vehicles. As a core component of new energy vehicles, batteries must meet high requirements in terms of both energy density and reliability.

[0101] In manufacturing a battery cell in the related art, an active material layer is applied to a current collector, which is then cut to obtain an electrode sheet consisting of a current collector coated with an active material layer (referred to as an active material coated portion) and a current collector not coated with an active material layer (referred to as a tab sheet). Next, a positive electrode piece, a negative electrode piece, and a separator film are sequentially stacked or wound to obtain an electrode assembly, and multiple tab sheets in the electrode assembly are stacked and installed to form a tab portion. A pole is installed in the battery cell casing, and the surface of the pole facing the active material coated portion is the inner end surface of the pole. When manufacturing a battery cell, the tab portion is usually welded directly to the inner end surface of the pole or indirectly welded to the inner end surface of the pole via an adapter sheet to ensure normal charging and discharging operations.

[0102] However, the inventors have found that when a battery cell employs the above structure, the tab portion and adapter sheet are stacked between the active material coated portion and the inner end surface of the electrode post, occupying a relatively large space. Therefore, for a given casing size, the size of the active material coated portion cannot be increased, making it difficult to increase the energy density of the battery cell. Furthermore, if, for design or manufacturing reasons, the length of the tab portion is typically relatively long and the space between the active material coated portion and the inner end surface of the electrode post is relatively small, the tab portion will have redundancy issues after the electrode assembly is inserted into the casing, easily causing a short circuit between the tab portion or adapter sheet and the active material coated portion, which will affect the reliability and stability of the battery cell.

[0103] Based on the above concept, in order to improve the energy density, reliability, and stability of the battery cell, the inventors conducted in-depth research and designed a battery cell in which a receiving portion is provided on at least one of the poles of the battery cell, and at least a portion of the tab portion or adapter sheet, which does not contain active material and plays a conductive role, is received in the receiving portion, thereby reducing the space occupied by this portion in the casing and saving more space in the casing to receive the active material coated portion, thereby increasing the volume of the active material coated portion and further improving the energy density of the battery cell. This also reduces the redundancy of the tab portion or adapter sheet in the casing to a certain extent, reducing the probability of a short circuit between the tab portion or adapter sheet and the active material coated portion, thereby reducing the probability of reliability issues caused by short circuits and further improving the operational reliability and stability of the battery cell.

[0104] An embodiment of the present application provides an electric device using the battery cell of the present disclosure as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, an electric scooter, an electric car, a steamship, a spacecraft, etc. Among them, the electric toy may include a stationary or mobile electric toy, such as a game console, an electric car toy, an electric boat toy, and an electric plane toy, and the spacecraft may include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0105] For convenience of explanation, in the following embodiment, the structures of the electric device 1000, the battery 100, and the battery cell 10 of the present application will be described in detail using a vehicle as an electric device.

[0106] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of an electric device 1000, which is a vehicle provided by some embodiments of the present application. The vehicle may be a fuel-powered vehicle, a gas-powered vehicle, or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle, a range-extended vehicle, etc. A battery 100 is installed in the vehicle, and the battery 100 may be installed at the bottom, head, or tail of the vehicle. The battery 100 is used to supply power to the vehicle. For example, the battery 100 may function as an operating power source for the vehicle. The vehicle may further include a controller 200 and a motor 300. The controller 200 controls the battery 100 to supply power to the motor 300, for example, to meet the operating power needs during starting, navigation, and driving of the vehicle. In some embodiments of the present application, the battery 100 can be used not only as an operating power source for the vehicle but also as a driving power source for the vehicle, thereby providing driving power to the vehicle in place of or partially replacing fuel or natural gas.

[0107] Referring to FIG. 2, FIG. 2 is an exploded view of a structure in which battery cells 10 provided according to some embodiments of the present application are used in a battery 100. The battery 100 includes a case 20 and a plurality of battery cells 10 housed within the case 20. The case 20 provides an assembly space for the battery cells 10, and the case 20 can have various structures. In some embodiments, the case 20 can include a first case 201 and a second case 202, which cover each other and together define an assembly space for housing the battery cells 10. The second case 202 can have a hollow structure with one end open, or the first case 201 can have a plate-like structure, with the first case body 201 covering the open side of the second case 202 so that the first case 201 and the second case 202 jointly define the assembly space. Alternatively, the first case 201 and the second case 202 may both have a hollow structure with one side open (for example, as shown in FIG. 2), with the open side of the first case 201 being covered by the open side of the second case 202. Of course, the case 20 formed by the first case 201 and the second case 202 may have various shapes, such as a cylindrical shape or a rectangular parallelepiped shape.

[0108] In the battery 100, the plurality of battery cells 10 can be connected in series, parallel, or series-parallel, and a series-parallel connection means that the plurality of battery cells 10 are connected in both series and parallel. The plurality of battery cells 10 can also be connected in direct series, parallel, or series-parallel, and the entire plurality of battery cells 10 is housed within a case 20. Alternatively, the battery 100 may be in a form in which the plurality of battery cells 10 are first connected in series, parallel, or series-parallel to form a battery module, and the plurality of battery modules are further connected in series, parallel, or series-parallel to form an integrated battery module and housed within a case 20. The battery 100 may further include other structures; for example, the battery 100 may further include a bus member for realizing electrical connection between the plurality of battery cells 10.

[0109] Please refer to Figure 3, which is a schematic diagram of a battery cell 10 provided according to some embodiments of the present application. The battery cell 10 has a rectangular parallelepiped shape, and the height direction of the battery cell 10 is a first direction Z, the length direction of the battery cell 10 is a second direction X, and the thickness direction of the battery cell 10 is a third direction Y. The first direction Z, the second direction X, and the third direction Y are perpendicular to each other two by two. However, this is not limited thereto, and in other embodiments of the present application, the battery cell 10 may be cylindrical, flat, or have other shapes.

[0110] Referring to Figures 4 and 5, Figure 4 is an orthographic view of a battery cell 10 provided according to some embodiments of the present application, and Figure 5 is a cross-sectional view along line AA in Figure 4. In the embodiments of the present application, the battery cell 10 includes a casing assembly 1 including a casing 11 and a first pole 12 installed in the casing 11, and a battery core assembly 2.

[0111] The shape of the casing 11 can be adjusted according to the type of battery cell 10, and the type of battery cell 10 in the embodiments of the present application is not particularly limited. For example, if the battery cell 10 is a prismatic battery, the casing 11 will be rectangular, and if the battery cell 10 is a cylindrical battery, the casing 11 will be columnar. In the embodiments of the present application, the casing 11 will be rectangular. The casing 11 is provided with poles, which are used for electrical connection with the battery core assembly 2 to ensure normal charging and discharging of the battery cell 10. Generally, there are at least two poles, specifically, at least one positive pole and at least one negative pole. For example, if there are two poles, one is a positive pole and the other is a negative pole, which are electrically connected to the positive and negative output positions of the battery core assembly 2, respectively. Also, if there are four poles, two may be positive poles and the remaining two may be negative poles, with the two positive poles both electrically connected to the positive output position of the battery core assembly 2 and the two negative poles both electrically connected to the negative output position of the battery core assembly 2.

[0112] 6 is a structural schematic diagram of a battery cell 10 provided according to some embodiments of the present application, and FIG. 7 is an assembly diagram of a second electrode post 15, a battery core assembly 2, and a casing 11 provided according to some embodiments of the present application. Referring to FIGS. 1 to 7, in the embodiments of the present application, at least one of the plurality of electrode posts is a first electrode post 12, which may be a positive electrode post or a negative electrode post, and which has a receiving portion 121 formed therein. The receiving portion 121 is a virtual structure having a receiving space, which may be a groove-like structure, a hole-like structure, or a combination of a groove-like structure and a hole-like structure. In other words, all of the electrode posts in the casing 11 may be first electrode posts 12 formed with the receiving portion 121, or only some of the electrode posts in the casing 11 may be first electrode posts 12 formed with the receiving portion 121. When some of the poles in the casing 11 are first poles 12 having the receiving portion 121, the remaining poles in the casing 11 are second poles 15 (see FIGS. 6 and 7) having no receiving portion 121.

[0113] Regardless of whether the poles on the casing 11 are first poles 12 or second poles 15, both the first poles 12 and the second poles 15 are electrically connected to the battery core assembly 2 to ensure that the charging and discharging processes of the battery cells 10 are performed normally. Of course, in other embodiments of the present application, only one pole may be installed on the casing assembly 1, and that pole may be the first pole 12, and the first pole 12 may include two parts, which are insulated and connected, and serve as a positive pole and a negative pole, respectively. For simplicity of explanation, the following description will mainly focus on an embodiment in which all poles in the casing 11 are first poles 12 with receiving recesses 121 formed therein.

[0114] Referring again to Figures 3 to 7, in the embodiment of the present application, the battery core assembly 2 includes an active material-applied portion 21 and a conductive portion 22, the active material-applied portion 21 is housed within the casing 11, the active material-applied portion 21 is a portion of the battery core assembly 2 to which active material is applied and can assist in the detachment of metal ions during the charging and discharging process of the battery cell 10, and the conductive portion 22 is a metal structure that electrically connects the active material-applied portion 21 and the electrode post, and is not coated with active material, and both the first electrode post 12 and the second electrode post 15 can be electrically connected to the active material-applied portion 21 via the conductive portion 22 so that the charging and discharging operation of the battery cell 10 can be performed.

[0115] It should be noted that in the present embodiment, the active material-coated portion 21 is divided into a positive electrode active material-coated portion and a negative electrode active material-coated portion, the positive electrode active material-coated portion includes a portion of the positive electrode current collector where a positive electrode active material layer is coated, and the negative electrode active material-coated portion includes a portion of the negative electrode current collector where a negative electrode active material layer is coated. 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-coated portion and the positive electrode pole, and the negative electrode conductive portion electrically connects the negative electrode active material-coated portion and the negative electrode pole.

[0116] 4 and 5 , in the embodiment of the present application, at least a portion of the conductive portion 22 is accommodated in the corresponding receiving portion 121. Here, "at least a portion" means that the conductive portion 22 may be completely accommodated in the receiving portion 121, or that only a portion of the conductive portion 22 is accommodated in the receiving portion 121. Because the receiving portion 121 is provided in the first pole 12, the hollow structure of the receiving portion 121 reduces the weight of the pole 12 to some extent, thereby improving the weight-energy density of the battery cell 10 and the battery 100.

[0117] Furthermore, by accommodating a part or all of the conductive portion 22 in the accommodating portion 121, the portion of the conductive portion 22 accommodated in the accommodating portion 121 occupies space within the first electrode post 12, thereby reducing the space occupied by the conductive portion 22 within the casing 11. If the dimensions of the casing 11 are fixed, a larger active material-coated portion 21 can be accommodated within the casing 11 to save space and improve the volumetric energy density of the battery cell 10. For example, if the conductive portion 22 is pulled out from the side of the active material-coated portion 21 closest to the first electrode post 12, the space occupied by the conductive portion 22 between the active material-coated portion 21 and the first electrode post 12 can be saved. This increases the dimension of the active material-coated portion 21 in the direction in which the conductive portion 22 is pulled out, reducing the distance between the active material-coated portion 21 and the first electrode post 12, improving the energy density of the battery cell 10.

[0118] 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 is reduced, allowing more battery cells 10 to be accommodated in a battery 100 of the same volume, thereby improving 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, the conductive portion 22 occupies space within the first electrode post 12, thereby reducing at least some of the redundancy of the conductive portion 22 within the casing 11, reducing the probability of a short circuit between the conductive portion 22 and the active material-coated portion 21, and reducing the risk of a short circuit in the battery cell 10, thereby 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 is advantageous for stabilizing and positioning the conductive portion 22, improving the stability of the conductive portion 22, facilitating welding of the conductive portion 22 to the first electrode post 12, and improving assembly efficiency.

[0119] In some optional embodiments of the present application, referring again to Figures 3 to 5, each of the multiple poles in the casing assembly 1 is a first pole 12 having an accommodating portion 121, in which case more conductive portions 22 can be accommodated in all of the first poles 12, thereby further improving the volumetric energy density of the battery cell 10.

[0120] In some other optional embodiments of the present application, referring to Figures 6 and 7, at least one of the multiple poles in the casing assembly 1 is a first pole 12 having 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 combined according to actual needs such as energy density and cost, thereby improving the applicability of the battery cell 10.

[0121] 6 and 7, when the second electrode post 15 is installed on the casing 11, the clearance groove 18 may be installed between the second electrode post 15 and the casing 11 as needed, so that at least a portion of the conductive portion 22 is accommodated in the clearance groove 18. This can reduce the space occupied by the conductive portion 22 in the casing 11 to some extent, which is advantageous for improving the energy density and alleviating the short-circuit problem caused by the redundancy of the conductive portion 22.

[0122] In the embodiments of the present application, the receiving portion 121 may be located on the side facing the active material coated portion 21 of the first electrode post 12, or on the side away from the active material coated portion 21 of the first electrode post 12. For example, FIG. 8 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application, and FIG. 9 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIGS. 8 and 9, when the receiving portion 121 is located on the side facing the active material coated portion 21 of the first electrode post 12, the receiving portion 121 includes a first receiving groove 12110, the surface of the first electrode post 12 facing the active material coated portion 21 is the electrode post inner end surface 122, the groove opening of the first receiving groove 12110 is formed in the electrode post inner end surface 122, and at least a portion of the conductive portion 22 is received in the first receiving groove 12110.

[0123] For example, the first accommodating groove 12110 is a groove body, and the groove body has a groove-like structure with a certain depth. For example, when the first electrode post 12 is installed on the upper end wall of the casing 11 and the electrode post inner end surface 122 is the lower surface of the first electrode post 12, the first accommodating groove 12110 is formed as an accommodating groove with a groove opening downward and groove walls recessed upward. Also, when the first electrode post 12 is installed on the lower end wall of the casing 11 and the electrode post inner end surface 122 is the upper surface of the first electrode post 12, the first accommodating groove 12110 is formed as an accommodating groove with a groove opening upward and groove walls recessed downward.

[0124] In the above technical solution, by forming the first accommodating groove 12110 in the first pole 12, the weight of the first pole 12 can be reduced to a certain extent, improving the weight-to-energy density of the battery cell 10 and the battery 100. Meanwhile, because the groove opening of the first accommodating groove 12110 is formed on the inner end surface 122 of the pole, which is the surface of the first pole 12 that is closest to the active material-coated portion 21, the first accommodating groove 12110 can be opened toward the active material-coated portion 21, and the conductive portion 22 can extend into the first accommodating groove 12110, improving assembly efficiency. Furthermore, such a first accommodating groove 12110 is easy to process, improving production efficiency.

[0125] In addition, the first accommodating groove 12110 is easy to process and has a relatively large volume, so it can accommodate a larger number of conductive parts 22. At the same time, because the first accommodating groove 12110 is open toward the active material application portion 21, the first accommodating groove 12110 also functions as a buffer and temporary storage structure for the electrolyte, so that a larger amount of electrolyte can be accommodated within the casing 11. Since the electrolyte is consumed during the charging and discharging process of the battery cell 10, the service life of the battery cell 10 can be extended when there is a larger amount of electrolyte. Furthermore, because the first accommodating groove 12110 is open toward the active material application portion 21, the first accommodating groove 12110 can also be used as a buffer and buffer structure for gas generated inside the battery core assembly 2, so as to reduce the expansion of the battery cell 10 and improve the reliability and stability of the battery cell 10.

[0126] Furthermore, since the first accommodating groove 12110 is located inside the first pole 12, external foreign objects and impurities are less likely to enter the first accommodating groove 12110, reducing the impact of external foreign objects and impurities on the battery core assembly 2 and improving the stability and reliability of the operation of the battery core assembly 2, thereby improving the stability and reliability of the battery cell 10 and the battery 100.

[0127] 8, in the embodiment of the present application, the method of connecting the first terminal post 12 and the casing 11 is not limited, and may be, for example, welding or riveting. For example, when the two are fitted together by riveting, the casing 11 has a mounting hole 113, and the first terminal post 12 is attached by riveting to the mounting hole 113. Of course, when the two are fitted together by welding or another method, it can be understood that the casing 11 may have a mounting hole 113 so that the first terminal post 12 can be easily attached to the casing 11 through the mounting hole 113, and this is not limited here. In addition, the first accommodating groove 12110 may be installed corresponding to the position of the mounting hole 113, in other words, it may be installed corresponding to the projection plane perpendicular to the axial direction R of the first pole post 12. Since the orthogonal projection of the first accommodating groove 12110 is located within the orthogonal projection range of the mounting hole 113, the first accommodating groove 12110 has a greater depth and can accommodate more conductive parts 22, thereby significantly reducing the space occupied by the conductive parts 22 within the casing 11.

[0128] Specifically, a mounting hole 113 is opened in the casing 11, the first pole 12 is mounted in the mounting hole 113, and the depth H1 of the first accommodating groove 12110 along the axial direction R of the first pole 12 is greater than or equal to the minimum distance H2 from the pole inner end face 122 to the mounting hole 113.

[0129] It should be noted that the specific shape of the first housing groove 12110 is not particularly limited, and may be a regular or irregular shape, such as a cylindrical groove with a rectangular, elliptical, or racetrack-shaped cross section (a structure formed by two arc lines and two straight lines surrounding each other), a trapezoidal groove with a rectangular cross section and gradually varying cross-sectional dimensions, a hemispherical groove with a circular cross section and gradually varying cross-sectional dimensions, or a semi-elliptical groove with an elliptical cross section and gradually varying cross-sectional dimensions. Therefore, the depth H1 of the first housing groove 12110 refers to the maximum depth of the first housing groove 12110 along the axial direction R of the first pole post 12.

[0130] In the axial direction R of the first pole 12, the depth H1 of the first accommodating groove 12110 is equal to or greater than the minimum distance H2 from the pole inner end surface 122 to the mounting hole 113, making full use of the volume of the first pole 12. The first accommodating groove 12110 has a relatively large depth, which is advantageous for accommodating more conductive parts 22 and further reducing the space occupied by the conductive parts 22 within the casing 11, further improving the energy density of the battery cell 10 and further reducing the redundancy of the conductive parts 22 within the casing 11. At the same time, the relatively large depth of the first accommodating groove 12110 not only allows it to accommodate gas generated in the battery core assembly 2 and ensure the reliability and stability of the battery cell 10, but also allows it to accommodate more electrolyte and ensure the service life of the battery cell 10.

[0131] It should be further noted that the volume of the first receiving groove 12110 is not limited. For example, in some embodiments, the volume of the first receiving groove 12110 for receiving the conductive portion 22 (referred to as first volume V1) is 298 mm 3 This allows the first receiving groove 12110 to have a relatively sufficient space to receive the conductive portion 22, facilitating welding of the conductive portion 22 to the first pole 12. On the other hand, if the first volume V1 of the first receiving groove 12110 is 298 mm 3 If it is less than this, the ability of the first accommodating groove 12110 to accommodate the conductive portion 22 becomes relatively low, making it difficult to weld the conductive portion 22 and the first pole 12 together.

[0132] Furthermore, it should be explained that the first volume V1 of the first accommodating groove 12110 is the difference between the total volume V2 of the first accommodating groove 12110 and the volume (denoted as second volume V3) required for the first accommodating groove 12110 to accommodate components other than the conductive portion 22, i.e., V1 = V2 - V3. As can be understood, if the first accommodating groove 12110 does not need to accommodate components other than the conductive portion 22, the second volume V3 is 0 mm 3 For example, the first volume V1 of the first receiving groove 12110 can be 300 mm 3 ~1500mm 3 For example, 300 mm 3 , 400mm 3 , 500mm 3 , 600mm 3 , 700mm 3 , 800mm 3 , 1000mm 3 , 1200mm 3 , 1400mm 3 , 1500mm 3 etc.

[0133] 8 and 9 , to ensure the stability and reliability of the electrical connection between the active material coating portion 21 and the first electrode post 12, in this embodiment, the electrical connection position between the conductive portion 22 and the first electrode post 12 may be located on the groove wall of the first receiving groove 12110. For example, the conductive portion 22 and the first electrode post 12 may be electrically connected by welding, and the electrical connection position is the welding position between the conductive portion 22 and the first electrode post 12. The welding method between the conductive portion 22 and the first electrode post 12 is not limited and may be, for example, laser welding. Depending on factors such as the position, angle, or structure of the welding portion, vertical welding, angle welding, lap welding, edge welding, etc. may be selected. In other embodiments, the electrical connection between the conductive portion 22 and the first electrode post 12 may be achieved by other methods instead of welding, such as using a conductive adhesive or a conductive pin. For the sake of simplicity, the following description will be given taking as an example the conductive portion 22 and the first pole 12 being electrically connected by welding, and the welding position being the electrical connection position between the conductive portion 22 and the first pole 12.

[0134] Specifically, the first electrode post 12 specifically includes a first end wall 12111 and a first side wall 12113, the first end wall 12111 being located on the 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 surrounding each other forming a first accommodating groove 12110, and the electrical connection position between the conductive portion 22 and the first electrode post 12 being located on the first end wall 12111 and / or the first side wall 12113. In other words, the conductive portion 22 may be welded to at least one of the first end wall 12111 and the first side wall 12113.

[0135] In the above technical solution, the electrical connection position between the conductive portion 22 and the first pole 12 is located on at least one of the first end wall 12111 and the first side wall 12113. This allows the first receiving groove 12110 to receive at least a portion of the conductive portion 22, and the groove wall of the first receiving groove 12110 to establish electrical connection with the conductive portion 22. This simplifies the structure of the first pole 12, facilitates processing of the first pole 12, simplifies the structure of the conductive portion 22, reduces redundancy of the conductive portion 22, and reduces the cost of the structure of the conductive portion 22. Furthermore, using the groove wall of the first receiving groove 12110 to establish electrical connection with the conductive portion 22 allows for a relatively large electrical connection area between the conductive portion 22 and the first pole 12. This not only simplifies the electrical connection but also improves the reliability and stability of the electrical connection, thereby improving the performance of the battery cell 10.

[0136] Furthermore, by positioning the electrical connection position between the conductive portion 22 and the first pole 12 within the first accommodating groove 12110, not only can the electrical connection position be prevented from protruding outside the first pole 12 and occupying space other than the first pole 12, but the first pole 12 can be protected at the electrical connection position, thereby improving the reliability and stability of the electrical connection between the conductive portion 22 and the first pole 12.

[0137] Furthermore, in the embodiment of the present application, the first end wall 12111 has a sealed structure without any through holes so that the first accommodating groove 12110 is isolated from the external space of the casing 11, thereby avoiding the problem of the electrolyte in the casing 11 leaking from the first accommodating groove 12110.

[0138] 8 and 9, in the embodiment of the present application, the local shape of the conductive portion 22 matches the local shape of the first end wall 12111 and is closely arranged to achieve electrical connection, so that the electrical connection position between the conductive portion 22 and the first end wall 12111 extends along the length or width direction of the first end wall 12111. For example, if the first end wall 12111 is flat, the local portion of the conductive portion 22 may also be flat and be closely arranged to the first end wall 12111, and the closely arranged portion may be electrically connected by, for example, welding. This increases the electrical connection area and improves the reliability and stability of the electrical connection.

[0139] Furthermore, when the electrical connection between the conductive portion 22 and the first end wall 12111 is made by welding, the first end wall 12111 is located on the side of the first accommodating groove 12110 away from the active material application portion 21, making it easy to perform the welding operation, for example, by allowing welding to be performed from the side of the first pole 12 away from the active material application portion 21.

[0140] It should be noted that the shape of the first end wall 12111 is not limited, and may be, for example, a flat plate or an arcuate plate. Here, when the first end wall 12111 has a flat structure, the first end wall 12111 is disposed at an angle with the axial direction R of the first pole post 12, and may be, for example, a flat plate structure perpendicular to the axial direction R of the first pole post 12, or may be, for example, an inclined plate structure not perpendicular to the axial direction R of the first pole post 12, but the inclination direction is not limited.

[0141] Of course, in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the first end wall 12111 does not necessarily extend along the length or width of the first end wall 12111, but may be, for example, a plurality of discretely located points, for example, the conductive portion 22 has a plurality of spaced apart portions that are each welded to the first end wall 12111, and the description of these will be omitted here.

[0142] 10 is a schematic cross-sectional view of a battery cell 10 according to some embodiments of the present application. Referring to FIG. 10 , in the embodiment of the present application, when the conductive portion 22 is electrically connected to the first end wall 12111, a first sunken groove 12112 may be provided in the first end wall 12111, and the sunken direction of the first sunken groove 12112 is a direction away from the active material coated portion 21. At least a portion of the position where the conductive portion 22 is electrically connected to the first end wall 12111 is located within the first sunken groove 12112. For example, at least a portion of the conductive portion 22 may be located within the first sunken groove 12112 and connected to a portion of the first end wall 12111 that defines the first sunken groove 12112.

[0143] In the above technical solution, on the one hand, the first sunken groove 12112 can realize pre-positioning and position restriction of the electrical connection position of the conductive part 22, which is advantageous not only for achieving accurate positioning and electrical connection and improving production efficiency, but also for improving the stability and reliability of the conductive part 22 and ensuring the stability and reliability of the charge and discharge processes of the battery cell 10. On the other hand, by providing the first sunken groove 12112 in the first end wall 12111, the wall thickness of a local part of the first end wall 12111 can be locally thinned, which is not only advantageous for welding, but also for reducing the weight of the first pole 12 and improving the weight-energy density of the battery cell 10.

[0144] In some alternative embodiments, a portion of the conductive portion 22 is fitted to the shape of the first side wall 12113 and closely attached to it, for example, if the first side wall 12113 is curved, a portion of the conductive portion 22 may also be curved and closely attached to the first side wall 12113, and an electrical connection (e.g., welding) may be made at the closely attached position so that the electrical connection position between the conductive portion 22 and the first side wall 12113 extends along the first side wall 12113. This increases the electrical connection area and improves the reliability and stability of the electrical connection.

[0145] Of course, in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the first side wall 12113 does not necessarily extend along the first side wall 12113, but may be, for example, a plurality of discretely located points, for example, the conductive portion 22 has a plurality of spaced apart portions that are each welded to the first side wall 12113, and the description of these will be omitted here.

[0146] It should be noted that the number of first side walls 12113 is not limited and may be determined according to the shape of the first receiving groove 12110, as long as one end of each first side wall 12113 remote from the groove opening of the first receiving groove 12110 is connected to the first end wall 12111. For example, if the cross-sectional shape of the first receiving groove 12110 is circular or elliptical, the first end wall 12111 is also circular or elliptical, and there is one first side wall 12113 formed in an annular shape and installed around the periphery of the first end wall 12111. For further example, if the cross-sectional shape of the first receiving groove 12110 is rectangular or racetrack-shaped, the first end wall 12111 is also rectangular or racetrack-shaped, and there are four first side walls 12113 connected to the four sides of the first end wall 12111, respectively.

[0147] It should be further explained that the first accommodating 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 be present. In this case, the first accommodating groove 12110 can be defined only by the plurality of first side walls 12113 by gathering one end of each first side wall 12113 away from the groove mouth of the first accommodating groove 12110. In this case, the conductive portion 22 is electrically connected to the first side wall 12113, and it is only necessary to ensure that the charging and discharging process of the battery cell 10 is carried out normally.

[0148] It should also be noted that in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the first pole 12 does not have to be located within the first accommodating groove 12110. For example, the electrical connection position between the conductive portion 22 and the first pole 12 can be located on the pole inner end surface 122, in which case a portion of the conductive portion 22 is accommodated in the first accommodating groove 12110, saving some space and improving the energy density of the battery cell 10.

[0149] 9 and 10 again, in the embodiment of the present application, the first electrode post 12 may further be provided with a first groove 126 if necessary, and the first groove 126 is located on the side of the first electrode post 12 away from the active material application portion 21, i.e., the surface of the first electrode post 12 away from the active material application portion 21 is the electrode post outer end surface 123, and the groove opening of the first groove 126 is formed on the electrode post outer end surface 123.

[0150] As can be understood, the first groove 126 is a groove body, and the groove body has a groove-like structure with a certain depth. When the first electrode post 12 is installed on the upper end wall of the casing 11 and the electrode post outer end surface 123 is the upper surface of the first electrode post 12, the first groove 126 is formed as a groove with an opening facing upward and groove walls recessed downward (i.e., a square recessed groove adjacent to the battery core assembly 2). Also, when the first electrode post 12 is installed on the lower end wall of the casing 11 and the electrode post outer end surface 123 is the lower surface of the first electrode post 12, the first groove 126 is formed as a groove with an opening facing downward and groove walls recessed upward (i.e., a square recessed groove adjacent to the battery core assembly 2).

[0151] In the above technical solution, the first recess 126 is installed in the first pole 12, which further reduces the weight of the first pole 12 and improves the weight-energy density of the battery cells 10 and the battery 100. Meanwhile, the first recess 126 is located on the outside of the first pole 12, i.e., it is open toward the side of the first pole 12 that is away from the inside of the casing 11. Therefore, the first recess 126 can accommodate or mount structural components that are electrically connected to each battery cell 10 in the battery 100, which makes full use of the space within the first pole 12 and improves the space utilization rate and volumetric energy density of the battery 100.

[0152] Furthermore, because the first electrode post 12 has both the first accommodating groove 12110 and the first groove 126, and the first groove 126 is located on the side of the first accommodating groove 12110 that is away from the active material coated portion 21 and is open in the direction away from the first accommodating groove 12110, it is easy to laser-weld the conductive portion 22 and the first end wall 12111 through the first groove 126 from the outside of the first electrode post 12, i.e., the side of the first electrode post 12 that is away from the active material coated portion 21, and it is also easy to achieve an electrical connection between the conductive portion 22 and the first electrode post 12 by external welding. In other words, the above structure and installation makes it easy to externally weld the first electrode post 12 and the conductive portion 22 through the first groove 126, facilitating the processing and manufacturing of the battery cell 10 and reducing processing and manufacturing costs.

[0153] Furthermore, in order to easily and effectively weld the conductive portion 22 to the groove wall of the first accommodating groove 12110 through the first groove 126 and improve the welding reliability between the conductive portion 22 and the groove wall of the first accommodating groove 12110, in the embodiment of the present application, the portion between the first groove 126 and the first accommodating groove 12110 is laser welded to the conductive portion 22, that is, the gap portion 127 shown in Figure 10 is laser welded to the conductive portion 22, thereby realizing an electrical connection between the battery core assembly 2 and the first pole 12. The gap 127 between the first groove 126 and the first accommodating groove 12110 of the first pole 12 has a small thickness, and the gap 127 separates the first groove 126 from the first accommodating groove 12110. The wall surface of the gap 127 on the side closest to the active material application portion 21 can be the first end wall 12111. When the conductive portion 22 needs to be welded to the first end wall 12111, the relatively small thickness of the gap 127 is advantageous for welding the conductive portion 22 to the first end wall 12111 via the first groove 126, improving the convenience and reliability of the welding.

[0154] In some embodiments, the first accommodating groove 12110 may be configured with a cross-sectional shape in which the length is greater than the width, such as a rectangle, oval, or racetrack shape, and the weld mark formed by welding the conductive portion 22 to the first electrode post 12 may be an elongated weld mark parallel to the length direction of the first accommodating groove 12110 to improve the reliability of the weld and increase the current passing capacity. For example, when an elongated weld mark is formed by welding the conductive portion 22 to the first end wall 12111, the width of the weld mark may be 6 mm or more, and the distance between the weld mark and the first side wall 12113 may be 1 mm or more to ensure the convenience and reliability of the weld and maintain the current passing capacity of the battery cell 10.

[0155] Referring again to FIG. 9, the casing assembly 1 may further include a groove cover 7, which is mounted on the first pole post 12 and seals the opening of the first groove 126.

[0156] In the above technical solution, by installing a groove cover 7 to seal the first groove 126, the first pole 12 can achieve an indirect electrical connection with the bus member via the groove cover 7. The position and structure of the groove cover 7 make the electrical connection between the groove cover 7 and the bus member more convenient and increase the electrical connection area. Therefore, installing the groove cover 7 facilitates the electrical connection between adjacent battery cells 10 in the battery 100. Furthermore, because the electrical connection positions between the battery cells 10 are located on the groove cover 7, the electrical connection positions between the conductive part 22 and the first pole 12 can be separated by the first groove 126, reducing interference between them and further improving the stability and reliability of the battery cells 10.

[0157] It should be noted that based on the technical proposal that the accommodating portion 121 includes the first accommodating groove 12110, the specific configuration of the battery core assembly 2 in the examples of the present application is not limited, and may include, for example, but not limited to, the following two embodiments:

[0158] FIG. 11 is a schematic cross-sectional view of a battery core assembly 2 provided in some examples of the present application. Referring to FIGS. 9 to 11, in the first embodiment, the active material application 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 tab portion 221 electrically connected to the current collector 211, the tab portion 221 includes a plurality of tab sheets 2211, and the tab sheets 2211 are electrically connected to the current collector 211. This is a structure in which no active material is applied, and can be formed by directly stamping the current collector 211, and the multiple tab sheets 2211 gather at a position close to the current collector 211 (i.e., converge in a direction toward each other) to form a first converging portion 2212, and the multiple tab sheets 2211 gather at a position away from the current collector 211 and connect to form a second converging portion 2213, and the first converging portion 2212 connects the second converging portion 2213 to the active material-applied portion 21. When the accommodating portion 121 has a first accommodating groove 12110, at least a portion of the second converging portion 2213 can be accommodated in the first accommodating groove 12110.

[0159] In the above technical solution, the multiple tab sheets 2211 simply converge (i.e., converge toward each other) but are not connected when forming the first converging portion 2212, but when forming the second converging portion 2213, the multiple tab sheets 2211 not only converge but also connect to form an integral structure. For example, the multiple tab sheets 2211 can be connected to an integral plate-like structure by welding (e.g., ultrasonic welding) to form the second converging portion 2213, or the multiple tab sheets 2211 can be gathered and connected by a method such as bonding with a conductive adhesive to form the second converging portion 2213, and the description thereof will be omitted here.

[0160] For illustrative purposes, in the present embodiment, the tab sheet 2211 is divided into a positive electrode tab sheet 2211 and a negative electrode tab sheet 2211. The positive electrode tab sheets 2211 that need to converge are stacked and ultrasonically tack-welded to form a positive electrode second convergence portion 2213, thereby reducing the interlayer gap and forming a plate-like structure with a certain rigidity from the plurality of puffed positive electrode tab sheets 2211. Similarly, the negative electrode tab sheets 2211 that need to converge are stacked and ultrasonically tack-welded to form a negative electrode second convergence portion 2213, thereby reducing the interlayer gap and forming a plate-like structure with a certain rigidity from the plurality of puffed negative electrode tab sheets 2211.

[0161] In the above technical solution, "a plurality of tab sheets 2211 gather at a position close to the current collector 211 to form a first converging portion 2212, and a plurality of tab sheets 2211 gather at a position away from the current collector 211 to connect to form a second converging portion 2213" means that the first converging portion 2212 and the second converging portion 2213 are sequentially arranged along the extending direction of the tab sheets 2211 in a direction away from the current collector 211, and the specific positions of the first converging portion 2212 and the second converging portion 2213 are not limited, that is, it is not required how close the first converging portion 2212 is to the current collector 211 or how far the second converging portion 2213 is from the current collector 211. In some alternative embodiments, the current collector 211 and tab sheet 2211 may be a unitary member, such as an aluminum foil integrally molded with the positive electrode piece, or a copper foil integrally molded with the negative electrode piece.

[0162] In the above technical solution, the tab portion 221 includes a second converging portion 2213 formed by gathering and connecting multiple tab sheets 2211, so that at least a portion of the second converging portion 2213 is accommodated in the first accommodating groove 12110, which facilitates the connection between the conductive portion 22 and the first pole 12, makes full use of the space in the first pole 12, and improves the volumetric energy density of the battery cell 10.

[0163] 10 to 11 , in the first embodiment, at least a portion of the first converging portion 2212 is accommodated in the first accommodating groove 12110. In the above technical solution, at least a portion of the first converging portion 2212 and at least a portion of the second converging portion 2213 of the tab portion 221 are both accommodated in the first accommodating groove 12110, which makes better use of the space within the first pole 12, further reduces the space occupied by the tab portion 221 within the casing 11, allows a larger active material applied portion 21 to be accommodated, improves the volumetric energy density of the battery cell 10, and better reduces the redundancy of the tab portion 221 within the casing 11, thereby further reducing the probability of a short circuit between the tab portion 221 and the active material applied portion 21.

[0164] In this embodiment, the second converging portion 2213 and the first electrode post 12 are electrically connected directly or indirectly. For example, referring to Fig. 9, when the second converging portion 2213 is directly electrically connected to the first electrode post 12, for example, when the second converging portion 2213 is welded (e.g., laser welded) to the first electrode post 12, the structure of the battery core assembly 2 can be simplified, the number of parts can be reduced, the assembly flow can be simplified, and assembly efficiency can be improved. Here, the method and position of the direct electrical connection between the second converging portion 2213 and the first electrode post 12 are not limited. For example, the electrical connection position between the second converging portion 2213 and the first pole pillar 12 may be located on the first end wall 12111 and / or the first side wall 12113, and further, the electrical connection position between the second converging portion 2213 and the first end wall 12111 may extend along the length or width direction of the first end wall 12111, and further, the first end wall 12111 may have a first sunken groove 12112, and the electrical connection position between the second converging portion 2213 and the first end wall 12111 may be located within the first sunken groove 12112, etc. For corresponding technical effects, please refer to the descriptions of the above embodiments, and the description thereof will be omitted here.

[0165] In an optional technical solution, the conductive part 22 can further include an adapter sheet 222 if necessary, in which case the second converging part 2213 is indirectly electrically connected to the first pole 12. Specifically, referring to FIG. 10 , when the conductive part 22 includes the adapter sheet 222, the adapter sheet 222 is connected to the second converging part 2213, and the conductive part 22 is electrically connected to the first pole 12 via the adapter sheet 222. In this case, at least a portion of the adapter sheet 222 is accommodated in the first accommodating groove 12110, and in this example, at least a portion of the second converging part 2213 is also accommodated in the first accommodating groove 12110, but the first converging part 2212 may or may not be accommodated in the first accommodating groove 12110.

[0166] In the above technical solution, the active material coating portion 21 can be electrically connected to the first pole 12 via the first converging portion 2212, the second converging portion 2213, and the adapter sheet 222, in that order, and the electrical connection position between the conductive portion 22 and the first pole 12 is located on the adapter sheet 222. For example, the electrical connection can be achieved by welding (e.g., laser welding) the adapter sheet 222 to the first pole 12. Furthermore, the adapter sheet 222 and the tab sheet 2211 are two separate members that are connected by a method such as welding (e.g., ultrasonic welding).

[0167] In the above technical solution, at least a portion of the second converging portion 2213 and at least a portion of the adapter sheet 222 are all accommodated in the first accommodating groove 12110, thereby more fully utilizing the space within the first pole 12, further reducing the space occupied by the conductive part 22 within the casing 11, and improving the volumetric energy density of the battery cell 10. On the other hand, when at least a portion of the first converging portion 2212, at least a portion of the second converging portion 2213, and at least a portion of the adapter sheet 222 are all accommodated in the first accommodating groove 12110, more fully utilizing the space within the first pole 12, more effectively reducing the space occupied by the conductive part 22 within the casing 11, and further improving the volumetric energy density of the battery cell 10.

[0168] On the other hand, by using the adapter sheet 222 to achieve an indirect electrical connection between the second converging portion 2213 and the first electrode post 12, the adapter sheet 222 can be welded to the first electrode post 12 using the portion that avoids the second converging portion 2213, thereby firmly welding the adapter sheet 222 to the first electrode post 12, reducing the risk of weld cracks and further improving the reliability and stability of the battery cell 10. At the same time, by electrically connecting the first electrode post 12 and the tab sheet 2211 using the adapter sheet 222, the structure of the tab sheet 2211 can also be simplified.

[0169] Here, the method and location of direct electrical connection between the adapter sheet 222 and the first electrode post 12 are not limited. For example, the adapter sheet 222 and the first electrode post 12 are electrically connected by welding. For example, the electrical connection position between the adapter sheet 222 and the first electrode post 12 may be located on the first end wall 12111 and / or the first side wall 12113. Furthermore, the electrical connection position between the adapter sheet 222 and the first end wall 12111 may extend along the length or width direction of the first end wall 12111. Furthermore, the first end wall 12111 may have a first recessed groove 12112, and the electrical connection position between the adapter sheet 222 and the first end wall 12111 may be located within the first recessed groove 12112. For corresponding technical effects, please refer to the descriptions of the above embodiments, and further description thereof will be omitted here. When the electrical connection position between the adapter sheet 222 and the first pole 12 is located on the first end wall 12111 and / or the first side wall 12113, at least a portion of the adapter sheet 222 is accommodated in the first accommodating groove 12110, thereby simplifying the structure of the adapter sheet 222, reducing redundancy and reducing costs.

[0170] 10 to 11 , in the second embodiment, the active material application 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 tab portion 221 and an adapter sheet 222, the tab portion 221 includes a plurality of tab sheets 2211 electrically connected to the current collector 211, the plurality of tab sheets 2211 gather at a position close to the current collector 211 to form a first converging portion 2212, the plurality of tab sheets 2211 gather at a position away from the current collector 211 to connect to form a second converging portion 2213, and the adapter sheet 222 is electrically connected to the second converging portion 2213. When the accommodating portion 121 has a first accommodating groove 12110, at least a portion of the adapter sheet 222 can be accommodated in the first accommodating groove 12110 and is electrically connected to the first electrode post 12.

[0171] In the above technical solution, the second embodiment differs from the technical solution including the adapter sheet 222 of the first embodiment in that in the second embodiment, at least a portion of the adapter sheet 222 is accommodated in the first accommodating groove 12110, but the relative position of the tab portion 221 and the first accommodating groove 12110 is not limited, that is, at least a portion of the tab portion 221 can be accommodated in the first accommodating groove 12110, or the tab portion 221 can be located completely outside the first accommodating groove 12110, thereby meeting different structural design requirements.

[0172] In the above technical solution, at least a portion of the adapter sheet 222 is accommodated in the first accommodating groove 12110, allowing the adapter sheet 222 to occupy space within the first pole 12, thereby reducing the space occupied by the adapter sheet 222 within the casing 11, accommodating a larger-sized active material application portion 21, improving the volumetric energy density of the battery cell 10, and reducing the probability of a short circuit between the adapter sheet 222 and the active material application portion 21, thereby reducing the risk of a short circuit in the battery core assembly 2, and improving the stability and reliability of the battery cell 10.

[0173] Furthermore, by using the adapter sheet 222 to achieve an indirect electrical connection between the second converging portion 2213 and the first electrode post 12, the adapter sheet 222 can be welded to the first electrode post 12 using the portion that avoids the second converging portion 2213, thereby firmly welding the adapter sheet 222 to the first electrode post 12, reducing the risk of weld cracks and further improving the reliability and stability of the battery cell 10. At the same time, by electrically connecting the first electrode post 12 and the tab sheet 2211 using the adapter sheet 222, the structure of the tab sheet 2211 can also be simplified.

[0174] For example, in some optional examples, for example, in the above Example 1 or the following third embodiment, when the second converging portion 2213 is directly electrically connected to the first electrode pole 12, the conductive portion 22 may be composed of only the positive electrode tab and the negative electrode tab of each electrode assembly 2 a. For example, in some other examples, for example, in the above Example 1 or Example 2, or the following third or fourth embodiment, when the second converging portion 2213 is indirectly electrically connected to the first electrode pole 12 via the adapter sheet 222, the conductive portion 22 may be composed of the positive electrode tab, the negative electrode tab, and the adapter sheet 222 of each electrode assembly 2 a.

[0175] FIG. 12 is a diagram illustrating a converging design for multiple tabs of a battery core assembly 2 provided according to some embodiments of the present application. Referring to FIGS. 11 and 12, in some embodiments, when the battery core assembly 2 includes two electrode assemblies 2a, the tab sheets 2211 of the two electrode assemblies 2a may converge together, and the convergence position may be at a central position between the two electrode assemblies 2a, forming a symmetrically converged shape (e.g., as shown in FIGS. 11 and 12(a)). In other embodiments, when the tab sheets 2211 of the two electrode assemblies 2a converge together, the convergence position may be adjacent to one electrode assembly 2a, forming an asymmetrically converged shape (e.g., as shown in FIGS. 12(b) and 12(c)). Furthermore, the electrode assemblies 2a may have a fully extended tab shape (e.g., as shown in FIG. 12(a)) or a half-extended tab shape (e.g., as shown in FIGS. 11, 12(b), and 12(c)).

[0176] Of course, the tab sheets 2211 of the same polarity of the two electrode assemblies 2a do not have to converge together. For example, the tab sheets 2211 of each electrode assembly 2a may converge independently for the positive and negative electrodes, i.e., the positive electrode tabs of one electrode assembly 2a may converge independently, and the positive electrode tabs of the other electrode assembly 2a may converge independently, but this will not be described here.

[0177] It should be noted that the receiving portion 121 in the embodiment of the present application does not necessarily have to have the first receiving groove 12110, and for example, some other alternative embodiments are shown below.

[0178] For example, Figure 13 is a schematic local cross-sectional view of a battery cell 10 provided by some embodiments of the present application. Referring to Figure 13, in the embodiment of the present application, the accommodating portion 121 may be configured to include a second accommodating groove 12120, the surface of the first pole 12 facing away from the active material application portion 21 is the pole outer end surface 123, the groove opening of the second accommodating groove 12120 is formed in the pole outer end surface 123, the second accommodating groove 12120 communicates with the inside of the casing 11 through the first through hole 12130, and the conductive portion 22 is drilled in the first through hole 12130 and at least a portion of it is accommodated in the second accommodating groove 12120.

[0179] As can be understood, the second accommodating groove 12120 is a groove body, which has a groove-like structure with a certain depth. For example, when the first electrode pole 12 is installed on the upper end wall of the casing 11 and the electrode pole outer end surface 123 is the upper surface of the first electrode pole 12, the second accommodating groove 12120 is formed as an accommodating groove with an opening facing upward and groove walls recessed downward. Also, when the first electrode pole 12 is installed on the lower end wall of the casing 11 and the electrode pole outer end surface 123 is the lower surface of the first electrode pole 12, the second accommodating groove 12120 is formed as an accommodating groove with an opening facing downward and groove walls recessed upward.

[0180] In the above technical solution, referring to FIG. 13 , by providing the second receiving groove 12120 on the first pole 12, the weight of the first pole 12 can be reduced to some extent, and the weight energy density of the battery cell 10 and the battery 100 can be improved. Meanwhile, the groove opening of the second receiving groove 12120 is formed on the pole outer end surface 123, which is the surface of the first pole 12 away from the active material coated portion 21. Therefore, the second receiving groove 12120 can be used to apply the active material It can be opened in a direction away from the application portion 21, and by accommodating at least a portion of the conductive portion 22 in the second accommodating groove 12120, the conductive portion 22 can be easily accommodated and organized through the groove opening of the second accommodating groove 12120, and electrical connection operations between the conductive portion 22 and the first pole 12 can be easily performed through the groove opening of the second accommodating groove 12120, thereby reducing the difficulty of producing the battery cell 10 and improving the production efficiency of the battery cell 10.

[0181] At the same time, because the second accommodating groove 12120 is connected to the inside of the casing 11 through the first through-hole 12130, the second accommodating groove 12120 can also be used as a buffering and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated in the casing 11. Since the electrolyte is consumed during the charging and discharging process of the battery cell 10, the service life of the battery cell 10 can be extended when there is more electrolyte. Furthermore, because the second accommodating groove 12120 is connected to the inside of the casing 11 through the first through-hole 12130, the second accommodating groove 12120 can also be used as a buffering structure for the gas generated inside the battery core assembly 2, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0182] It should be noted that when the accommodating portion 121 has a second accommodating groove 12120, the conductive portion 22 is drilled in the first through hole 12130, and at least a portion of the conductive portion 22 is accommodated in the second accommodating groove 12120, the electrical connection position between the conductive portion 22 and the first pole 12 is not limited.

[0183] For example, when the conductive portion 22 is drilled in the first through hole 12130 and at least a portion of it is accommodated in the second accommodating groove 12120, in the embodiment 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.

[0184] In the above technical solution, the electrical connection position between the conductive part 22 and the first electrode post 12 is located on the hole wall of the first through hole 12130, so that the electrical connection operation between the conductive part 22 and the first electrode post 12 can be easily performed through the second accommodating groove 12120. Furthermore, when the electrical connection area between the conductive part 22 and the first electrode post 12 is relatively large, the electrical connection between the conductive part 22 and the first electrode post 12 can be used to realize sealing of the first through hole 12130, thereby saving sealing costs and reducing electrolyte leakage and saving sealing materials.

[0185] Specifically, by welding the conductive part 22 to the wall of the first through hole 12130 at the position where the first through hole 12130 and the second accommodating groove 12120 are connected, operation is made easier, and by controlling the welding marks, the welding marks and the conductive part 22 can be used to seal the first through hole 12130, thereby improving the problem of the electrolyte in the casing 11 leaking from the first through hole 12130.

[0186] Further, for example, when the conductive portion 22 is drilled in the first through-hole 12130 and at least a portion thereof is accommodated in the second accommodating groove 12120, in some other embodiments of the present application, the electrical connection position between the conductive portion 22 and the first electrode post 12 may also be located on the groove wall of the second accommodating groove 12120 formed by the first electrode post 12. This facilitates the electrical connection operation and, for example, can prevent conductive particles produced by welding from entering the casing 11 and causing problems such as short circuits when the conductive portion 22 is welded to the groove wall of the second accommodating groove 12120 formed by the first electrode post 12.

[0187] Specifically, Figure 14 is a local cross-sectional schematic diagram of a battery cell 10 provided by some embodiments of the present application. Referring to Figures 13 and 14, the first pole 12 includes a second end wall 12121 and a second side wall 12123, the second end wall 12121 is located on the side of the second side wall 12123 close to the active material application portion 21, the second end wall 12121 and the second side wall 12123 surround each other to form a second accommodating groove 12120, a first through hole 12130 is opened in the second end wall 12121, and the electrical connection position between the conductive portion 22 and the first pole 12 is located on the second end wall 12121 and / or the second side wall 12123.

[0188] More specifically, the conductive portion 22 and the first electrode post 12 can be electrically connected by welding, and therefore the welding position is the electrical connection position between the conductive portion 22 and the first electrode post 12. In other embodiments of the present application, the conductive portion 22 and the first electrode post 12 can be electrically connected by other methods instead of welding, such as by using a conductive adhesive or installing a conductive pin, and the description thereof will be omitted here.

[0189] For the sake of simplicity, the following description will be given taking as an example that the conductive portion 22 and the first pole 12 are electrically connected by welding, and the welding position is the electrical connection position between the conductive portion 22 and the first pole 12. For example, in some embodiments, the electrical connection position between the conductive portion 22 and the first pole 12 may be located on 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.

[0190] In the above technical solution, the electrical connection position between the conductive portion 22 and the first electrode post 12 is located on at least one of the second end wall 12121 and the second side wall 12123. This allows the second receiving groove 12120 to not only receive at least a portion of the conductive portion 22, but also allows the groove wall of the second receiving groove 12120 to establish electrical connection with the conductive portion 22, thereby simplifying the structure of the first electrode post 12 and facilitating processing of the first electrode post 12. Furthermore, the first through-hole 12130 is formed in the second end wall 12121, allowing the conductive portion 22 to extend into the second receiving groove 12120 through the first through-hole 12130. This simplifies the structure of the conductive portion 22, reduces redundancy of the conductive portion 22, and reduces the cost of the conductive portion 22. In addition, the opening direction of the groove opening of the second accommodating groove 12120 can facilitate the electrical connection operation between the conductive part 22 and the groove wall of the second accommodating groove 12120 through the groove opening of the second accommodating groove 12120, reducing the difficulty of the electrical connection. Furthermore, by realizing the electrical connection with the conductive part 22 using the groove wall of the second accommodating groove 12120, the electrical connection area between the conductive part 22 and the first pole 12 can be set relatively large, improving the reliability and stability of the electrical connection and further improving the performance of the battery cell 10.

[0191] Furthermore, by positioning the electrical connection position between the conductive portion 22 and the first pole 12 within the second accommodating groove 12120, not only is it possible to prevent the electrical connection position from protruding outside the first pole 12 and occupying space other than the first pole 12, but the first pole 12 is protected at the electrical connection position, thereby improving the reliability and stability of the electrical connection between the conductive portion 22 and the first pole 12.

[0192] 13 and 14 , in some embodiments, the local shape of the conductive portion 22 matches the local shape of the second end wall 12121 and is closely positioned to achieve electrical connection, such that the electrical connection position between the conductive portion 22 and the second end wall 12121 extends along the length or width of the second end wall 12121. For example, if the second end wall 12121 is flat, the local portion of the conductive portion 22 may also be flat and be closely positioned to the second end wall 12121, and the closely positioned portion may be electrically connected by, for example, welding. This increases the electrical connection area and improves the reliability and stability of the electrical connection.

[0193] It should be noted that the shape of the second end wall 12121 is not limited, and may be, for example, a flat plate-like structure, an arc-shaped plate-like structure, etc. Here, when the second end wall 12121 has a flat plate-like structure, the second end wall 12121 is disposed at an angle with the axial direction R of the first electrode post 12, and may be, for example, a flat plate-like structure perpendicular to the axial direction R of the first electrode post 12, or may be, for example, an inclined flat plate-like structure not perpendicular to the axial direction R of the first electrode post 12, but the inclination direction is not limited.

[0194] 13 and 14, when the second end wall 12121 has a flat plate-like structure, the angle θ between the second end wall 12121 and the axial direction R of the first electrode post 12 is equal to 90°, that is, the second end wall 12121 and the active material coating portion 21 are equidistant from each other along the direction from the first through-hole 12130 to the second side wall 12123. This facilitates welding of the conductive portion 22 and the second end wall 12121.

[0195] 15 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIG. 15, the angle θ between the second end wall 12121 and the axial direction R of the first electrode post 12 is greater than 90°. That is, the second end wall 12121 extends at an angle from the first through-hole 12130 to the second side wall 12123 toward the active material-coated portion 21. This allows the conductive portion 22 to extend a longer distance along the second end wall 12121, 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 pole 12 is 90° to 145°, and may be, for example, 100°, 110°, 120°, 130°, 140°, etc., which makes it easier to process the second end wall 12121 and to easily make electrical connection with the conductive portion 22, while also making relatively full use of the space within the first pole 12 to accommodate the conductive portion 22.

[0196] 16 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIG. 16, the angle θ between the second end wall 12121 and the axial direction R of the first electrode post 12 is less than 90°, that is, the second end wall 12121 extends at an angle away from the active material-coated portion 21 along the direction from the first through-hole 12130 to the second side wall 12123. This allows the conductive portion 22 to extend a longer distance along the second end wall 12121, 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 pole 12 is 45° to 90°, and may be, for example, 50°, 60°, 70°, 80°, etc., which makes it easier to process the second end wall 12121 and to easily make electrical connection with the conductive portion 22, while also making relatively full use of the space within the first pole 12 to accommodate the conductive portion 22.

[0197] Of course, in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the second end wall 12121 does not necessarily extend along the length or width of the second end wall 12121, but may be a plurality of discretely arranged points, for example, the conductive portion 22 may have a plurality of spaced apart portions that are respectively welded to the second end wall 12121, and the description of these will be omitted here.

[0198] 14 again, regardless of the specific value of the angle θ between the second end wall 12121 and the axial direction R of the first electrode post 12, in any embodiment of the present application, when the conductive portion 22 is electrically connected to the second end wall 12121, a second sunken groove 12122 can be provided in the second end wall 12121 as needed. The second sunken groove 12122 is a recessed groove formed by partially sinking toward an end of the second end wall 12121 that is close to the local active material-coated portion. At least a portion of the position where the conductive portion 22 is electrically connected to the second end wall 12121 is located within the second sunken groove 12122.

[0199] In the above technical solution, the portion of the conductive part 22 located within the second sunken groove 12122 is installed to fit the shape of the second sunken groove 12122, is installed closely, and is electrically connected, so that the second sunken groove 12122 can be used to realize pre-positioning and position restriction of the electrical connection position of the conductive part 22, and the electrical connection can be performed with accurate positioning, which is beneficial to improving production efficiency and can improve the stability and reliability of the electrical connection position, thereby ensuring the reliability and stability of the charging and discharging operation of the battery cell 10.

[0200] It should be noted that in the embodiments of the present application, a portion of the conductive portion 22 can be fitted to the shape of the second side wall 12123 and be closely fitted to it, for example, if the second side wall 12123 is curved, a portion of the conductive portion 22 can also be curved and be closely fitted to the second side wall 12123, and the electrical connection (e.g., welding) can be performed at the closely fitted position so that the electrical connection position between the conductive portion 22 and the second side wall 12123 extends along the second side wall 12123. This can increase the electrical connection area and improve the reliability and stability of the electrical connection.

[0201] It should be noted that in other embodiments of the present application, the electrical connection position between the conductive portion 22 and the second side wall 12123 does not necessarily extend along the second side wall 12123, but may be, for example, a plurality of discretely arranged points, for example, the conductive portion 22 has a plurality of spaced apart portions that are each welded to the second side wall 12123, and the description of which will be omitted here.

[0202] As can be understood, the number of second side walls 12123 is not limited and may be determined according to the shape of the second receiving groove 12120, as long as one end of each second side wall 12123 remote from the groove opening of the second receiving groove 12120 is connected to the second end wall 12121. For example, if the cross-sectional shape of the second receiving groove 12120 is circular or elliptical, the second end wall 12121 is also circular or elliptical, and there is one second side wall 12123 formed in an annular shape and installed around the periphery of the second end wall 12121. For further example, if the cross-sectional shape of the second receiving groove 12120 is rectangular or racetrack-shaped, the second end wall 12121 is also rectangular or racetrack-shaped, and there are four second side walls 12123 connected to the four sides of the second end wall 12121, respectively.

[0203] It should also be noted that the second accommodating groove 12120 is not limited to a shape defined by the second end wall 12121 and the second side wall 12123. For example, in some embodiments, Figure 17 is a schematic local cross-sectional view of a battery cell 10 provided by some embodiments of the present application. Referring to Figure 17, one end of each second side wall 12123 away from the groove mouth of the second accommodating groove 12120 all extends to the first through hole 12130, so that the second accommodating groove 12120 is defined only by a plurality of second side walls 12123. In this case, the conductive portion 22 can be electrically connected to the second side wall 12123.

[0204] In some embodiments, referring to FIG. 29 , the receiving portion 121 may have a third receiving groove 12140 and a second receiving groove 12120 at the same time, the second receiving groove 12120 is located on the side of the third receiving groove 12140 away from the active material coated portion 21, the third receiving groove 12140 is a groove body, and the groove body has a groove-like structure with a certain depth, the groove opening of the third receiving groove 12140 is formed on the electrode post inner end surface 122 on the side close to the active material coated portion 21 of the first electrode post 12, and the groove opening of the second receiving groove 12120 is formed on the side of the first electrode post 12 close to the active material coated portion 21 of the first electrode post 12. The third accommodating groove 12140 is formed on the outer end surface 123 of the pole away from the adhesive application portion 21, and the third accommodating groove 12140 and the second accommodating groove 12120 are connected via the first through hole 12130. In this case, a part of the conductive portion 22 is located in the third accommodating groove 12140, and at the same time, the conductive portion 22 is further drilled into the first through hole 12130, and another part of the conductive portion 22 is located in the second accommodating groove 12120. This makes it possible to make relatively full use of the space within the first pole 12 and reduce the space occupied by the conductive portion 22 within the casing 11.

[0205] It should be noted that when the conductive portion 22 is connected to the second end wall 12121 or the second side wall 12123 by laser welding, referring again to Fig. 17, the angle β between the portion of the conductive portion 22 used for welding and the axis of the first through hole 12130 should be set to be greater than 5°, which will reduce the problem of the laser entering the casing 11 through the first through hole 12130 and is advantageous for the welding operation. Furthermore, when the angle β between the portion of the conductive portion 22 used for welding and the axis of the first through hole 12130 is close to 5°, edge welding can be used, and the other portions can be connected by lap welding.

[0206] 13 again, in the embodiment of the present application, the method of connecting the first terminal post 12 and the casing 11 is not limited, and may be, for example, welding or riveting. For example, when the two are fitted together by riveting, the casing 11 has a mounting hole 113, and the first terminal post 12 is attached by riveting to the mounting hole 113. Of course, it can be understood that when the two are fitted together by welding or another method, the casing 11 may have a mounting hole 113 so that the first terminal post 12 is attached to the casing 11 through the mounting hole 113.

[0207] Optionally, referring to FIG. 13, the second accommodating groove 12120 may be installed corresponding 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 orthogonal projection of the second accommodating groove 12120 is located within the orthogonal projection range of the mounting hole 113. The second accommodating groove 12120 has a relatively large depth and can accommodate more conductive parts 22. As a result, the space occupied by the conductive parts 22 in the casing 11 can be significantly reduced.

[0208] In some embodiments, referring to FIG. 13 , when the casing 11 has a mounting hole 113 and the first pole 12 is mounted in the mounting hole 113, the depth H3 of the second accommodating groove 12120 along the axial direction R of the first pole 12 is greater than or equal to the minimum distance H4 from the pole outer end surface 123 to the mounting hole 113.

[0209] It should be noted that the specific shape of the second storage groove 12120 is not particularly limited and may be a regular or irregular shape, such as a cylindrical groove with a uniform cross section, such as a rectangular, elliptical, or racetrack-shaped cross section, a trapezoidal groove with a rectangular cross section and gradually varying cross-sectional dimensions, a hemispherical groove with a circular cross section and gradually varying cross-sectional dimensions, or a semi-elliptical groove with an elliptical cross section and gradually varying cross-sectional dimensions, etc. It should be noted that the racetrack shape described herein refers to, for example, the shape shown in Figure 19(b), where the two short sides of the rectangle are replaced with convex curves.

[0210] Therefore, the depth H3 of the second accommodating groove 12120 refers to the maximum depth of the second accommodating groove 12120 along the axial direction R of the first electrode post 12. In the axial direction R of the first electrode post 12, the depth H3 of the second accommodating groove 12120 is equal to or greater than the minimum distance H4 from the electrode post outer end surface 123 to the mounting hole 113. This allows full utilization of the volume of the first electrode post 12, and the second accommodating groove 12120 has a relatively large depth, which is advantageous for accommodating more conductive parts 22 and further reduces the space occupied by the conductive parts 22 within the casing 11, further improving the energy density of the battery cell 10 and further reducing the redundancy of the conductive parts 22 within the casing 11. At the same time, the relatively large depth of the second accommodating groove 12120 not only allows it to accommodate gas generated in the battery core assembly 2 and ensure the reliability and stability of the battery cell 10, but also allows it to accommodate more electrolyte and ensure the service life of the battery cell 10.

[0211] It should be noted that the volume of the second receiving groove 12120 is not limited, and for example, in some specific examples, the volume of the second receiving groove 12120 (referred to as a third volume V4) for receiving the conductive portion 22 is 298 mm 3 or more, so that the second accommodating groove 12120 can have a relatively sufficient space to accommodate the conductive portion 22 and facilitate welding of the conductive portion 22 to the first terminal post 12. On the other hand, when the third volume V4 of the second accommodating groove 12120 is 298 mm 3If the third volume V4 of the second accommodating groove 12120 is less than 300 mm, the capacity of the second accommodating groove 12120 to accommodate the conductive portion 22 becomes relatively low, making it difficult to weld the conductive portion 22 to the first terminal post 12. For example, if the third volume V4 of the second accommodating groove 12120 is 300 mm 3 , 400mm 3 , 500mm 3 , 600mm 3 , 700mm 3 , 800mm 3 , 1000mm 3 etc. may also be used.

[0212] It should be noted that the third volume V4 of the second receiving groove 12120 is the difference between the total volume V5 of the second receiving groove 12120 and the volume (referred to as a fourth volume V6) required for the second receiving groove 12120 to receive other components (e.g., the first cover plate 13 and the second cover plate 14 described in this specification) other than the conductive portion 22, i.e., V4 = V5 - V6. For example, in some specific examples, the total volume V5 of the second receiving groove 12120 is 1400 mm 3 ~1500mm 3 This allows the second accommodating groove 12120 to have more sufficient space to accommodate the conductive portion 22 and other components. For example, the total volume V5 of the second accommodating groove 12120 is 1420 mm 3 , 1440mm 3 , 1460mm 3 , 1480mm 3 , 1490mm 3 etc. may also be used.

[0213] In the embodiments of the present application, there are no limitations on the shape of the first through holes 12130, the number of the first through holes 12130, and the relative positional relationship between the first through holes 12130 and the second receiving grooves 12120.

[0214] 18 is an enlarged view of a portion B in FIG. 3, and FIG. 19 is an orthogonal projection view of several types of first pole posts 12 provided by some embodiments of the present application. Referring to FIGS. 18 and 19, the shape of the first through hole 12130 in the present embodiment may be elongated to fit the sheet-like local shape of the conductive portion 22, thereby favoring the penetration of the sheet-like local portion of the conductive portion 22. At the same time, when the first through hole 12130 is elongated, the second receiving groove 12120 may be configured with a shape whose cross-sectional length is greater than its width, such as a rectangle, an oval, or a racetrack shape. In this case, the length direction of the first through hole 12130 can be aligned with the cross-sectional length direction of the second receiving groove 12120, thereby making full use of space. Furthermore, the weld mark formed by welding the conductive portion 22 to the first electrode post 12 may be an elongated weld mark parallel to the length of the first through hole 12130, so as to improve the reliability of the weld and increase the current passing capacity. For example, when the conductive portion 22 and the second end wall 12121 are welded to form an elongated weld mark, the width of the weld mark may be 6 mm or more, and the distance between the weld mark and the second side wall 12123 may be 1 mm or more, in order to ensure the convenience and reliability of the weld and at the same time maintain the current passing capacity of the battery cell 10.

[0215] Regarding the size and number of the first through-holes 12130, in the embodiments of the present application, the opening size and specific position of the first through-holes 12130 in the second accommodating groove 12120 are not limited, and related designs can be made according to the number of first through-holes 12130. For example, the width of the first through-hole 12130 may be 2 mm or more, which is advantageous for the passage of the conductive part 22. For example, when only one first through-hole 12130 is opened in the second accommodating groove 12120, in some examples, as shown in FIGS. 18 and 19, the first through-hole 12130 may be disposed centrally relative to the second accommodating groove 12120. In other examples, as shown in FIG. 20, which is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application, the first through-hole 12130 may be disposed off-center relative to the second accommodating groove 12120. For example, in some embodiments, referring to FIG. 20, the first through hole 12130 can be opened at the edge of the second end wall 12121 so as to be located close to the second side wall 12123, thereby increasing the available area of ​​the second end wall 12121 and increasing the welding area between the conductive portion 22 and the second end wall 12121.

[0216] As will be understood, after the conductive portion 22 passes through the first through hole 12130, it is folded back so as to fit closely to the second end wall 12121, but the folding direction is not limited. For example, if the first through hole 12130 is centrally located relative to the second accommodating groove 12120, the conductive portion 22 can be folded back toward any side of the first through hole 12130 after passing through the first through hole 12130 (see FIG. 18 ), thereby appropriately reducing the size of the second accommodating groove 12120 and improving the compactness and strength of the structure. Alternatively, FIG. 21 is a schematic cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIG. 21 , after the conductive portion 22 passes through the first through hole 12130, it can be folded back toward opposite sides at the same time, thereby reducing the thickness of the welding point, reducing heat input during welding, and reducing problems such as particle scattering.

[0217] For example, when there are multiple first through holes 12130 formed in the second receiving groove 12120, the multiple first through holes 12130 are arranged parallel or nearly parallel in the length direction so as to fully utilize the space. In this case, the folding direction of the conductive part 22 after passing through the first through hole 12130 can be set based on the relative positional relationship of the multiple first through holes 12130. For example, Figure 22 is a schematic local cross-sectional view of a battery cell 10 provided by some embodiments of the present application. Referring to Figure 22, when there are two first through holes 12130 opened in the second accommodating groove 12120 and they are spaced apart, the two conductive parts 22 passing through the two first through holes 12130 can be folded back in a direction toward each other, and when there are two first through holes 12130 opened in the second accommodating groove 12120 and they are spaced apart, the two conductive parts 22 passing through the two first through holes 12130 can be folded back in a direction away from each other.

[0218] As can be understood, when there are multiple first through holes 12130 opened in the second accommodating groove 12120, the number of first pole posts 12 can be appropriately reduced, thereby reducing costs and processes.

[0219] Also, in some embodiments, referring to Figures 20 and 21, the first through hole 12130 can be positioned centrally relative to the active material application portion 21, but the position of the first through hole 12130 relative to the second accommodating groove 12120 is not limited and may be positioned centrally or off-center, and since the first through hole 12130 is positioned centrally relative to the active material application portion 21, the conductive portion 22 can converge in accordance with the center line position of the active material application portion 21.

[0220] 21 , in some embodiments, a seal 6 may be installed in the first through-hole 12130 to address the problem of electrolyte in the casing 11 leaking through the first through-hole 12130. The material, shape, and connection method of the seal 6 with the first through-hole 12130 are not limited. For example, the seal 6 may be made of the same material as the first electrode post 12 or the conductive part 22 and may be welded to the wall of the first through-hole 12130 of the first electrode post 12 to seal the first through-hole 12130. For example, the seal 6 may be made of rubber or plastic and inserted into the first through-hole 12130 with a tight fit to seal the first through-hole 12130. In the embodiments of the present application, any of these may be designed according to actual needs and are not limited thereto.

[0221] Figure 23 is an exploded view of a battery cell 10 provided in some embodiments of the present application, Figure 24 is a schematic cross-sectional view of a casing assembly 1 provided in some embodiments of the present application, and Figure 25 is an exploded view of the casing assembly 1 shown in Figure 24. Referring to Figures 23, 24 and 25, in the embodiments of the present application, when the accommodating portion 121 has the second accommodating groove 12120 of any one of the above embodiments, optionally, the casing assembly 1 may further include a first cover plate 13, which is fitted with the first pole 12 and seals the groove opening of the second accommodating groove 12120, and the first cover plate 13 is electrically connected to the first pole 12.

[0222] In the above technical proposal, by installing the first cover plate 13 so as to seal the groove opening of the second accommodating groove 12120, it is possible to prevent the electrolyte in the casing 11 from leaking from the groove opening of the second accommodating groove 12120. Furthermore, by sealing the groove opening of the second accommodating groove 12120 and electrically connecting the first electrode post 12 with the first cover plate 13, it is possible to easily realize an indirect electrical connection between the first electrode post 12 and the bus member using the first cover plate 13, which is advantageous for increasing the connection area of ​​the electrical connection point and further reducing the resistance of the electrical connection point.

[0223] It should be noted that the method and position of fitting the first cover plate 13 and the first pole 12 are not limited as long as the groove opening of the second accommodating groove 12120 of the first cover plate 13 can be sealed. For example, in some embodiments, referring to FIG. 22 , the first cover plate 13 may be welded to the first pole 12, and during processing, the conductive portion 22 may first be passed through the first through-hole 12130 and welded to the groove wall of the second accommodating groove 12120, and then the first cover plate 13 and the first pole 12 may be welded to seal the groove opening of the second accommodating groove 12120.

[0224] It should be further explained that the specific configuration of the first cover plate 13 is not limited. For example, in some optional embodiments, Fig. 26 is an exploded view of the configuration of the first cover plate 13 shown in Fig. 25. Referring to Figs. 24 to 26, the first cover plate 13 includes a first conductive member 131 and a second conductive member 132 made of different materials, the first conductive member 131 is fitted with and electrically connected to the first pole 12, and the second conductive member 132 is fitted with and electrically connected to the first conductive member 131.

[0225] In the above technical solution, the first cover plate 13 is installed in a composite form, and the first conductive member 131 is installed so that it is made of the same material as the first pole 12, which facilitates electrical connection between the first conductive member 131 and the first pole 12. For example, the first conductive member 131 and the first pole 12 can be reliably and stably connected by welding. Furthermore, because the second conductive member 132 and the first conductive member 131 are made of a different material, the second conductive member 132 can be used to easily electrically connect to bus members made of a different material from the first pole 12. For example, the second conductive member 132 can be reliably and stably connected to bus members made of the same material as the second conductive member 132 by welding.

[0226] For example, if the first electrode post 12 is a negative electrode post, the first electrode post 12 is a copper post, and the bus member is an aluminum sheet, the first conductive member 131 can be made of copper and the second conductive member 132 can be made of aluminum. In this case, the first electrode post 12 and the first conductive member 131 can be made of the same material and effectively welded together, and the second conductive member 132 and the bus member can be made of the same material and effectively welded together, thereby effectively realizing an indirect electrical connection between the first electrode post 12 and the bus member via the first cover plate 13. Furthermore, the first electrode post 12 and the first conductive member 131 are welded together from copper, which has excellent fluidity, is less likely to crack, and improves the sealing effect of the welded joints.

[0227] 24 to 26 again, in some optional examples, the first conductive member 131 is located between the second accommodating groove 12120 and the second conductive member 132. In the above technical solution, the first conductive member 131 is located between the second accommodating groove 12120 and the second conductive member 132, and therefore the second accommodating groove 12120 and the second conductive member 132 can be separated from each other. As a result, when the electrolyte in the casing 11 enters the second accommodating groove 12120 through the first through-hole 12130, the first conductive member 131 can be used to prevent that portion of the electrolyte from coming into contact with the second conductive member 132, thereby solving the problem of the electrolyte corroding the second conductive member 132.

[0228] It should be noted that the method of fitting the first conductive member 131 and the second conductive member 132 is not limited. For example, in some embodiments, referring to FIGS. 24 to 26 , the first conductive member 131 has a second groove 1311, the second conductive member 132 is fitted into the second groove 1311, and the opening of the second groove 1311 is formed on the surface of the first conductive member 131 away from the second receiving groove 12120 so that the second conductive member 132 is exposed from the opening of the second groove 1311. Alternatively, in other embodiments, the method of connecting the first conductive member 131 and the second conductive member 132 may be a fastening connection, an engagement, or the like.

[0229] It should be further explained that the second conductive member 132 being "exposed" from the groove opening of the second groove 1311 means that the first conductive member 131 does not block the second conductive member 132 at the groove opening position of the second groove 1311, and the second conductive member 132 does not need to protrude from the groove opening of the second groove 1311; for example, the second conductive member 132 may be positioned flush with the surface of the first conductive member 131 facing away from the second accommodating groove 12120, or the second conductive member 132 may protrude from the surface of the first conductive member 131 facing away from the second accommodating groove 12120.

[0230] In the above technical solution, the second conductive member 132 is fitted into the first conductive member 131, which reduces the difficulty of assembling the first conductive member 131 and the second conductive member 132 and improves the fitting stability and convenience of the first conductive member 131 and the second conductive member 132. It also reduces the thickness of the first cover plate 13, reduces the space occupied by the first cover plate 13, and improves the space utilization rate of the battery cell 10. On the other hand, the second conductive member 132 can be exposed through the opening of the second groove 1311 on the surface of the first conductive member 131 facing away from the second receiving groove 12120, which is advantageous for achieving electrical connection between the second conductive member 132 and the bus member on the outer side of the first pole 12.

[0231] Furthermore, since the groove opening of the second groove 1311 is formed on the surface of the first conductive member 131 that is away from the second accommodating groove 12120, it is suggested that the second groove 1311 opens in the direction away from the active material application portion 21. As a result, a portion of the groove wall of the second groove 1311 of the first conductive member 131 is located between the second accommodating groove 12120 and the second conductive member 132, thereby separating the second accommodating groove 12120 and the second conductive member 132 and preventing contact between the electrolyte that has entered the second groove 1311 and the second conductive member 132, thereby reducing leakage of the electrolyte.

[0232] Of course, in other embodiments, the first cover plate 13 does not have to be a composite type made of multiple materials. For example, in other embodiments of the present application, FIG. 27 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application, and FIG. 28 is an exploded structural view of the battery cell 10 shown in FIG. 27. Referring to FIGS. 27 and 28, the entire first cover plate 13 can be installed in a non-composite type made of the same material, for example, to fit the positive pole, and the description thereof will be omitted here.

[0233] 24 to 26 again, in some embodiments, the first cover plate 13 is further fitted into the groove opening of the second accommodating groove 12120. In the above technical solution, fitting the first cover plate 13 into the second accommodating groove 12120 reduces the difficulty of assembling the first cover plate 13 and the first pole 12, improves the assembly stability and connection reliability and convenience between the first cover plate 13 and the first pole 12, and reduces the space occupied by the first cover plate 13 other than the first pole 12. In addition, because the first cover plate 13 is fitted into the groove opening of the second accommodating groove 12120, the second accommodating groove 12120 has a relatively sufficient space for accommodating the conductive part 22.

[0234] Of course, in other embodiments of the present application, the method of fitting the first cover plate 13 and the first pole 12 is not limited to being fitted into the second accommodating groove 12120, and the first cover plate 13 may also be fitted over the outside of the first pole 12, that is, directly covering the groove opening of the second accommodating groove 12120 to facilitate fitting with the bus member of the battery 100, and is not limited in this embodiment.

[0235] 24 to 26 again, optionally, in the embodiment of the present application, at least a part of the wall surface where the groove opening of the second accommodating groove 12120 of the first pole 12 is formed is a guide slope 12126, and the guide slope 12126 is used to guide the fitting of the first cover plate 13 with the groove opening of the second accommodating groove 12120. In the above technical solution, by processing the wall surface of the groove opening of the second accommodating groove 12120 into a slope having a guide function, it is possible to reduce the difficulty of assembling the first cover plate 13 and the second accommodating groove 12120 and improve the assembly efficiency of the first cover plate 13 and the second accommodating groove 12120. Furthermore, when the first cover plate 13 is welded to the guide slope 12126, the area of ​​the welding point is increased, which improves the reliability of the welding connection between the first cover plate 13 and the first pole 12 and reduces the problem of the molten pool collapsing or the laser entering the first pole 12 during welding.

[0236] 24 to 26, the second accommodating groove 12120 includes a first groove section 12124 and a second groove section 12125 located on the side of the first groove section 12124 that is 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, so the second accommodating groove 12120 is formed in a stepped groove shape, and the connection position between the first groove section 12124 and the second groove section 12125 forms a stepped surface 12127. Therefore, when the first cover plate 13 is fitted into the second accommodating groove 12120, it is fitted into the second groove section 12125 and is supported by the stepped surface 12127.

[0237] In the above technical solution, by configuring the second accommodating groove 12120 in a stepped groove format, the first cover plate 13 can be stably fitted into the groove opening 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 step 12124, a relatively sufficient space can be provided in the second accommodating groove 12120 to accommodate the conductive part 22.

[0238] Furthermore, when the wall surface on which the groove mouth of the second accommodating groove 12120 of the first pole post 12 is formed is the guide slope 12126, the cross-sectional area of ​​the second groove step 12125 is set to gradually increase along the direction approaching the pole post outer end surface 123, so that the side wall of the second groove step 12125 forms the guide slope 12126, thereby facilitating processing and meeting the guide requirements simply and effectively.

[0239] 24 to 26 again, in the embodiment of the present application, the first cover plate 13 may further be provided with stress relief grooves 133 if necessary, and the stress relief grooves 133 are located in the outer circumferential region of the first cover plate 13 to help relieve stress on the first cover plate 13. In the above technical solution, the stress relief grooves 133 are provided in the first cover plate 13 to release stress generated during the processing of the first cover plate 13 itself or during the electrical connection between the first cover plate 13 and the first pole 12, so as to improve problems such as deformation and damage caused by stress on the first cover plate 13.

[0240] Specifically, when the first cover plate 13 is fitted into the second receiving groove 12120 and welded, the stress relief groove 133 relieves stress generated during welding, improves lateral heat conduction, and reduces the possibility of damage or deformation of the first cover plate 13. At the same time, if the first cover plate 13 is a composite type including the first conductive member 131 and the second conductive member 132, the stress relief groove 133 is provided in the first conductive member 131 and located at the outer circumferential region of the second conductive member 132. Therefore, when the first conductive member 131 is fitted into the second receiving groove 12120 and welded, the stress relief groove 133 relieves stress generated during welding, improves lateral heat conduction, and reduces the possibility of damage or deformation of the second conductive member 132. In addition, when the second conductive member 132 and the first conductive member 131 are fitted and welded, the stress relief groove 133 releases the stress generated by the welding, improves the lateral conduction of heat, and reduces the probability of deformation of the first conductive member 131 or the first conductive member 131 being unable to be fitted into the second accommodating groove 12120.

[0241] Referring to Figures 27 to 28, in the embodiment of the present application, a second cover plate 14 may be further installed on the casing assembly 1 if necessary, and the second cover plate 14 is installed to cover the outside of the first through hole 12130 and at the same time is located outside the conductive portion 22 in the second accommodating groove 12120.

[0242] It should be noted that when the casing assembly 1 includes the second cover plate 14, the casing assembly 1 may also include the first cover plate 13, or may not also include the first cover plate 13. Furthermore, when the casing assembly 1 includes both the second cover plate 14 and the first cover plate 13, the first cover plate 13 may be a composite type using multiple types of materials, or a non-composite type using the same material.

[0243] In the above technical solution, at least a portion of the conductive portion 22 is located in the second accommodating groove 12120, and the second cover plate 14 covers that portion of the conductive portion 22, and the second cover plate 14 is further configured to cover the first through hole 12130. This alleviates the problem of the electrolyte in that portion overflowing from the first pole 12 when the electrolyte enters the second accommodating groove 12120 through the first through hole 12130, thereby improving the reliability of the battery cell 10.

[0244] 27 and 28, when a portion of the conductive portion 22 is sandwiched between the second cover plate 14 and the second end wall 12121, laser welding can be used to weld together the three components of the portion of the conductive portion 22, the second cover plate 14, and the second end wall 12121, so as 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 press the conductive portion 22, the second cover plate 14 can improve the stability with which the conductive portion 22 is accommodated in the second accommodating groove 12120.

[0245] In the present embodiment, the first electrode post 12 may be an integrally molded electrode post or a separately molded composite electrode post. Referring again to Figures 27 and 28, for example, the first electrode post 12 may include a first electrode post portion 124 and a second electrode post portion 125 made of different materials and electrically connected to each other, with the second electrode post portion 125 located on the side of the first electrode post portion 124 away from the active material coated portion 21, and the receiving portion 121 attached to the first electrode post portion 124, or the receiving portion 121 attached to the first electrode post portion 124 and the second electrode post portion 125, and the conductive portion 22 electrically connected to the first electrode post portion 124.

[0246] In the above technical solution, the first pole 12 is configured in a composite form using a combination of different materials, and the first pole portion 124 located on the inside is used to fit and electrically connect with the conductive portion 22, and the second pole portion 125 located on the outside is used to electrically connect with bus members, etc. This is advantageous for assembling and electrically connecting the first pole 12 and related members, reduces mutual interference between the electrical connection position between the first pole 12 and the conductive portion 22 and the electrical connection position between the first pole 12 and the bus members of the battery 100, and improves the reliability and stability of the battery cell 10.

[0247] For example, if the material of the conductive part 22 is different from the material of the bus member, the first electrode post part 124 can be installed so that it is made of the same material as the conductive part 22, and the second electrode post part 125 can be installed so that it is made of the same material as the bus member. This allows welding between the second electrode post part 125 and the bus member, and welding between the first electrode post part 124 and the conductive part 22, which is advantageous in improving the reliability and stability of the electrical connection between the conductive part 22 and the first electrode post 12, and between the first electrode post 12 and the bus member.

[0248] Furthermore, when the first pole 12 is of the composite type as described above and has the second receiving groove 12120 and the first through-hole 12130 as described above, in some embodiments, the casing assembly 1 can also include the second cover plate 14 as described above. In this case, the second cover plate 14 and the first pole portion 124 can be made of the same material, and the first pole portion 124 can be electrically connected to the second cover plate 14, 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 can be connected by welding.

[0249] For example, referring to Figures 27 and 28, if the first electrode pole 12 is a negative electrode pole, the first electrode pole portion 124 is made of copper material, the second electrode pole portion 125 is made of aluminum material, and the bus member is an aluminum sheet, the second cover plate 14 can be installed on the copper material and the first cover plate 13 can be installed on the aluminum material. In this case, the second cover plate 14 and the first electrode pole portion 124 may be made of the same material and effectively welded, the second electrode pole portion 125 and the first cover plate 13 may be made of the same material and effectively welded, and the first cover plate 13 and the bus member may be made of the same material and effectively welded.

[0250] In the examples of the present application, when the accommodating portion 121 has a second accommodating groove 12120, the engagement between the battery core assembly 2 and the second accommodating groove 12120 is not limited depending on the configuration of the battery core assembly 2, and includes, for example, the following two examples of the third and fourth embodiments, but is not limited thereto.

[0251] 29 is a schematic cross-sectional view of a battery cell 10 according to some embodiments of the present application. Referring to FIG. 29 , in a third embodiment, the active material coated portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211. The conductive portion 22 is electrically connected to the current collector 211 and includes a tab portion 221 including a plurality of tab sheets 2211. The plurality of tab sheets 2211 gather at a position close to the current collector 211 to form a first converging portion 2212. The plurality of tab sheets 2211 gather at a position away from the current collector 211 to connect to form a second converging portion 2213. The first converging portion 2212 connects the second converging portion 2213 to the active material coated portion 21. When the accommodating portion 121 has a second accommodating groove 12120, at least a portion of the second converging portion 2213 is accommodated in the second accommodating groove 12120.

[0252] It should be noted that the specific configuration of the battery core assembly 2 in the third embodiment is basically the same as the specific configuration of the battery core assembly 2 in the above-mentioned Example 1, and the description of Example 1 can be referred to, so the description thereof will be omitted here. In the third embodiment, the tab portion 221 includes a second converging portion 2213 formed by gathering and connecting a plurality of tab sheets 2211, so that at least a portion of the second converging portion 2213 can be accommodated in the second accommodating groove 12120, facilitating the assembly of the conductive portion 22 and the first pole 12.

[0253] In some optional examples, referring to FIG. 29, the position where the first convergent portion 2212 and the second convergent portion 2213 are connected can be set corresponding to the first through hole 12130. In other words, on the projection plane perpendicular to the axial direction R of the first pole pillar 12, the orthogonal projection of the connection position between the first convergent portion 2212 and the second convergent portion 2213 is located within the orthogonal projection range of the first through hole 12130, so that the second convergent portion 2213 can be easily extended to the first through hole 12130 in a short distance and enter the second accommodating groove 12120, thereby reducing redundancy and saving costs.

[0254] It should be understood that the converging position of the tab sheet 2211 can be designed based on the position of the first through-hole 12130, for example, by adopting the above-mentioned symmetrical converging form or asymmetrical converging form, and the connection position between the first converging portion 2212 and the second converging portion 2213 can be set corresponding to the first through-hole 12130, but the description thereof will be omitted here. Also, as mentioned above, when the second converging portion 2213 forms a plate-like structure by ultrasonic tack welding, it is easy for the second converging portion 2213 to pass through the first through-hole 12130.

[0255] Referring to Figure 29, in the third embodiment, the accommodating portion 121, in addition to having the second accommodating groove 12120, may also have a third accommodating groove 12140 located on the side of the second accommodating groove 12120 that is close to the active material application portion 21, the surface of the first pole 12 facing the active material application portion 21 is the pole inner end face 122, and the groove opening of the third accommodating groove 12140 is formed in the pole inner end face 122, and the third accommodating groove 12140 and the second accommodating groove 12120 are connected via the first through hole 12130, and in this case, at least a portion of the first converging portion 2212 may be accommodated in the third accommodating groove 12140.

[0256] In the above technical solution, at least a portion of the first converging portion 2212 of the tab portion 221 is accommodated in the third accommodating groove 12140, and at least a portion of the second converging portion 2213 is accommodated in the second accommodating groove 12120, thereby making better use of the space within the first pole 12 to accommodate a larger-sized active material applied portion 21, further reducing the space occupied by the tab portion 221 within the casing 11, improving the energy density of the battery cell 10, and better reducing the redundancy of the tab portion 221 within the casing 11, further reducing the probability of a short circuit between the tab portion 221 and the active material applied portion 21, and further reducing the risk of the tab portion 221 being inserted backwards into the active material applied portion 21.

[0257] It should be noted that the specific shape of the third receiving groove 12140 is not limited, and may be a regular or irregular shape, such as a cylindrical groove with a uniform cross-section, such as a rectangular, elliptical, or racetrack-shaped cross-section, a trapezoidal groove with a rectangular cross-section and gradually varying cross-sectional dimensions, a hemispherical groove with a circular cross-section and gradually varying cross-sectional dimensions, or a semi-elliptical groove with an elliptical cross-section and gradually varying cross-sectional dimensions, etc. In the embodiments of the present application, the third receiving groove 12140 may be configured with a cross-sectional shape in which the length is greater than the width, such as a rectangular, elliptical, or racetrack-shaped shape, which is advantageous for receiving the first converging portion 2212.

[0258] In the third embodiment, the second converging portion 2213 is electrically connected directly or indirectly to the first electrode post 12. For example, when the second converging portion 2213 is electrically connected directly to the first electrode post 12, for example, when the second converging portion 2213 is welded to the first electrode post 12, the structure of the battery core assembly 2 can be simplified, the number of components can be reduced, the assembly flow can be simplified, and assembly efficiency can be improved. Here, the method and position of the direct electrical connection between the second converging portion 2213 and the first electrode post 12 are not limited. For example, the electrical connection position between the second converging portion 2213 and the first pole 12 may be located on the second end wall 12121 and / or the second side wall 12123, and further, the electrical connection position between the second converging portion 2213 and the second end wall 12121 may extend along the length or width direction of the second end wall 12121, and further, the second end wall 12121 may have a second sunken groove 12122, and the electrical connection position between the second converging portion 2213 and the second end wall 12121 may be located within the second sunken groove 12122, etc. For corresponding technical effects, please refer to the descriptions of the above embodiments, and the description thereof will be omitted here.

[0259] In an optional technical solution, the conductive portion 22 can further include an adapter sheet 222 if necessary, in which case the second converging portion 2213 is indirectly electrically connected to the first electrode post 12. Specifically, FIG. 30 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIG. 30, if the conductive portion 22 includes an adapter sheet 222, the adapter sheet 222 is connected to the second converging portion 2213, and the conductive portion 22 is electrically connected to the first electrode post 12 through the adapter sheet 222. In this case, at least a portion of the adapter sheet 222 is accommodated in the second accommodating groove 12120, and in this example, at least a portion of the second converging portion 2213 is also accommodated in the second accommodating groove 12120.

[0260] In the above technical solution, the active material coating portion 21 can be electrically connected to the first pole 12 via the first converging portion 2212, the second converging portion 2213, and the adapter sheet 222, in that order, and the electrical connection position between the conductive portion 22 and the first pole 12 is located on the adapter sheet 222. For example, the electrical connection can be achieved by welding (e.g., laser welding) the adapter sheet 222 to the first pole 12. Furthermore, the adapter sheet 222 and the tab sheet 2211 are two separate members that are connected by a method such as welding (e.g., ultrasonic welding).

[0261] In the above technical solution, at least a portion of the second converging portion 2213 and at least a portion of the adapter sheet 222 are accommodated in the second accommodating groove 12120, thereby making better use of the space within the first pole 12 and further reducing the space occupied by the conductive portion 22 within the casing 11, thereby further improving the volumetric energy density of the battery cell 10. In addition, installing the adapter sheet 222 with a sheet structure makes it easy for the adapter sheet 222 to pass through the first through-hole 12130 and extend into the second accommodating groove 12120.

[0262] Furthermore, by using the adapter sheet 222 to achieve an indirect electrical connection between the second converging portion 2213 and the first electrode post 12, the adapter sheet 222 can be welded to the first electrode post 12 using the portion that avoids the second converging portion 2213, thereby firmly welding the adapter sheet 222 to the first electrode post 12, reducing the risk of weld cracks and further improving the reliability and stability of the battery cell 10. At the same time, by electrically connecting the first electrode post 12 and the tab sheet 2211 using the adapter sheet 222, the structure of the tab sheet 2211 can also be simplified.

[0263] Here, the method and location of direct electrical connection between the adapter sheet 222 and the first electrode post 12 are not limited. For example, the adapter sheet 222 and the first electrode post 12 are electrically connected by welding. For example, the electrical connection position between the adapter sheet 222 and the first electrode post 12 may be located on the second end wall 12121 and / or the second side wall 12123. Furthermore, the electrical connection position between the adapter sheet 222 and the second end wall 12121 may extend along the length or width direction of the second end wall 12121. Furthermore, the second end wall 12121 may have a second recessed groove 12122, and the electrical connection position between the adapter sheet 222 and the second end wall 12121 may be located within the second recessed groove 12122. For corresponding technical effects, refer to the descriptions of the above embodiments, and further description thereof will be omitted here. When the electrical connection position between the adapter sheet 222 and the first pole 12 is located on the second end wall 12121 and / or the second side wall 12123, at least a portion of the adapter sheet 222 is accommodated in the second accommodating groove 12120, thereby simplifying the structure of the adapter sheet 222, reducing redundancy and reducing costs.

[0264] 30 , in the fourth embodiment, the active material application portion 21 includes a current collector 211 and an active material layer 212 provided on the current collector 211, and the conductive portion 22 includes a tab portion 221 including a plurality of tab sheets 2211 electrically connected to the current collector 211, and an adapter sheet 222, where the plurality of tab sheets 2211 gather at a position close to the current collector 211 to form a first converging portion 2212, and the plurality of tab sheets 2211 gather at a position away from the current collector 211 to connect with each other to form a second converging portion 2213, and the adapter sheet 222 is electrically connected to the second converging portion 2213. When the accommodating portion 121 has a second accommodating groove 12120, at least a portion of the adapter sheet 222 can be accommodated in the second accommodating groove 12120 and is electrically connected to the first electrode post 12.

[0265] In the above technical solution, the fourth embodiment differs from the technical solution including the adapter sheet 222 of the third embodiment in that in the fourth embodiment, at least a portion of the adapter sheet 222 is accommodated in the second accommodating groove 12120, but the relative position of the tab portion 221 and the second accommodating groove 12120 is not limited, that is, at least a portion of the tab portion 221 can be accommodated in the second accommodating groove 12120, or the tab portion 221 can be located completely outside the second accommodating groove 12120, thereby meeting different structural design requirements.

[0266] In the above technical solution, by accommodating at least a portion of the adapter sheet 222 in the second accommodating groove 12120, the adapter sheet 222 can occupy space within the first pole 12, thereby reducing the space occupied by the adapter sheet 222 within the casing 11 to accommodate a larger-sized active material application portion 21, thereby improving the energy density of the battery cell 10 and reducing the probability of a short circuit between the adapter sheet 222 and the active material application portion 21, thereby reducing the risk of a short circuit of the battery core assembly 2, so as to improve the stability and reliability of the battery cell 10.

[0267] Furthermore, by using the adapter sheet 222 to achieve an indirect electrical connection between the second converging portion 2213 and the first electrode post 12, the adapter sheet 222 can be welded to the first electrode post 12 using the portion that avoids the second converging portion 2213, thereby firmly welding the adapter sheet 222 to the first electrode post 12, reducing the risk of weld cracks and further improving the reliability and stability of the battery cell 10. At the same time, by electrically connecting the first electrode post 12 and the tab sheet 2211 using the adapter sheet 222, the structure of the tab sheet 2211 can also be simplified.

[0268] FIG. 31 is a schematic cross-sectional view of a battery cell 10 according to some embodiments of the present application. Referring to FIG. 31, in some other embodiments of the present application, the receiving portion 121 has a fourth receiving groove 12150, and the fourth receiving groove 12150 is a groove body having a groove-like structure with a certain depth. The surface of the first pole 12 away from the active material coated portion 21 is the pole outer end surface 123, and the groove opening of the fourth receiving groove 12150 is The fourth accommodating groove 12150 is formed on the outer end surface 123 of the pole, and is connected to the inside of the casing 11 through the second through hole 12160. The conductive part 22 does not have to be accommodated in the fourth accommodating groove 12150; for example, the conductive part 22 may be drilled in the second through hole 12160, and the electrical connection position between the conductive part 22 and the first pole 12 is located on the hole wall of the second through hole 12160 formed in the first pole 12.

[0269] In the above embodiment, the provision of the fourth accommodating groove 12150 facilitates electrical connection between the conductive part 22 and the wall of the second through hole 12160. Furthermore, depending on the circumstances, the electrical connection between the conductive part 22 and the first electrode post 12 can be utilized to seal the second through hole 12160. For example, welding the conductive part 22 to the wall of the second through hole 12160 at the position where the second through hole 12160 and the fourth accommodating groove 12150 are connected can facilitate the operation. Furthermore, by controlling the welding marks, the second through hole 12160 can be sealed using the welding marks and the conductive part 22, thereby alleviating the problem of electrolyte leakage from the casing 11 through the second through hole 12160.

[0270] It should be noted that the specific shape of the fourth receiving groove 12150 is not limited, and may be a regular or irregular shape, such as a cylindrical groove with a uniform cross section, such as a rectangular, elliptical, or racetrack-shaped cross section, a trapezoidal groove with a rectangular cross section and gradually varying cross-sectional dimensions, a hemispherical groove with a circular cross section and gradually varying cross-sectional dimensions, or a semi-elliptical groove with an elliptical cross section and gradually varying cross-sectional dimensions.

[0271] In the embodiment of the present application, the shape of the second through hole 12160 may be elongated to fit the sheet-like local shape of the conductive portion 22, which is advantageous for penetrating the sheet-like local portion of the conductive portion 22. At the same time, when the second through hole 12160 is elongated, the fourth accommodating groove 12150 may also be configured with a shape whose cross-sectional length is greater than its width, such as a rectangular, oval, or racetrack shape. In this case, the length direction of the second through hole 12160 can be aligned with the cross-sectional length direction of the fourth accommodating groove 12150, thereby making full use of space.

[0272] It should be noted that the receiving portion 121 in the embodiments of the present application does not necessarily have to have the at least one receiving groove. For example, in some embodiments of the present application, Fig. 32 is a schematic cross-sectional view of a local portion of a battery cell 10 provided by some embodiments of the present application. Referring to Fig. 32, the receiving portion 121 may have only a third through hole 12170, the surface of the first electrode post 12 facing the active material coated portion 21 is the electrode post inner end surface 122, and the surface of the first electrode post 12 facing away from the active material coated portion 21 is the electrode post outer end surface 123. The third through hole 12170 has the form of a through hole and penetrates the electrode post inner end surface 122 and the electrode post outer end surface 123, and at least a portion of the conductive portion 22 is drilled in the third through hole 12170. The electrical connection position between the conductive portion 22 and the first electrode post 12 is not limited. For example, the electrical connection position may be located on the hole wall where the third through hole 12170 of the first electrode post 12 is formed. Alternatively, the conductive portion 22 may penetrate the third through hole 12170 so that the electrical connection position is located on the outer end surface 123 of the electrode post outside the third through hole 12170. The shape of the third through hole 12170 is not limited. It may be a hole with a regular cross section or a hole with an irregular cross section. Furthermore, the cross-sectional shape of the third through hole 12170 is not limited. It may be an elongated shape, such as a rectangle, ellipse, or racetrack, to match the sheet-like local shape of the conductive portion 22. This is advantageous for the sheet-like local portion of the conductive portion 22 to be drilled into the third through hole 12170, and a description thereof will be omitted here.

[0273] FIG. 33 is a schematic cross-sectional view of a battery cell 10 according to some embodiments of the present application, FIG. 34 is a schematic view of the engagement between a battery core assembly 2 and a support 3 according to some embodiments of the present application, and FIG. 35 is a cross-sectional view taken along line CC in FIG. 34. Referring to FIGS. 33 to 35, in the embodiment of the present application, the battery cell 10 further includes a support 3, which is located within the casing 11 and is located on the side of the active material-coated portion 21 that is close to the first pole 12, and which has an escape hole 31 for avoiding the conductive portion 22, and which can extend through the escape hole 31 to the side of the support 3 that is away from the active material-coated portion 21 so as to be welded to the first pole 12, thereby ensuring that the charging and discharging operations of the battery cell 10 are performed normally.

[0274] In the above technical solution, by providing the support 3 on the side of the active material-coated portion 21 closest to the first pole 12, the support 3 can be used to separate the active material-coated portion 21 from the casing 11, improving the reliability of the battery cell 10. Furthermore, by providing the relief hole 31 in the support 3, the conductive portion 22 can be guided and restrained to pass through the relief hole 31 and engage with the first pole 12. This eliminates the need for the conductive portion 22 to detour around the edge of the support 3 to approach the first pole 12, further simplifying the arrangement of the conductive portion 22, saving material for the conductive portion 22 and reducing costs. Furthermore, the support 3 can be used to support and guide the engagement between the conductive portion 22 and the first pole 12, reducing the risk of a short circuit between the conductive portion 22 and the active material-coated portion 21 and further improving the reliability of the battery cell 10.

[0275] 33 to 35, a guide portion 32 is optionally provided on the support 3, and the guide portion 32 surrounds at least a part of the escape hole 31, and at least a part of the guide portion 32 extends to the accommodation portion 121.

[0276] It should be noted that the guide portion 32 protrudes from the support 3 and extends into the accommodating portion 121, and at least a portion of the escape hole 31 is formed within the guide portion 32. This allows at least a portion of the conductive portion 22 to be easily accommodated within the accommodating portion 121 when the conductive portion 22 is drilled through the escape hole 31, thereby improving the assembly efficiency of the conductive portion 22. At the same time, the installation of the guide portion 32 makes the fit between the support 3 and the first pole 12 and between the support 3 and the conductive portion 22 tighter and more reliable, making the structure of the battery cell 10 more compact and further advantageous for improving the energy density of the battery cell 10.

[0277] 33 to 35 again, the support 3 is optionally provided with a third recessed groove 38, and at least a portion of the first pole post 12 located in the casing 11 is housed in the third recessed groove 38.

[0278] In the above technical solution, the support 3 is provided with a third groove 38, and at least a portion of the first pole 12 located in the casing 11 is accommodated in the third groove 38, thereby improving the compactness of the structure, which is advantageous for reducing the space occupied by the support 3 in the casing 11, and for improving the volumetric energy density of the battery cell 10.

[0279] Furthermore, in some embodiments, the guide portion 32 can be involved in defining the third groove 38, which simplifies the structure of the support 3, reduces the difficulty of designing and processing the support 3, and is advantageous for increasing the wall thickness of the guide portion 32 and improving the guiding reliability of the conductive portion 32. It is also advantageous for improving the stability of the first pole 12, thereby ensuring the reliability of the electrical connection between the first pole 12 and the battery core assembly 2 and improving the reliability of the charging and discharging operations of the battery cell 10.

[0280] Referring again to Figures 33 to 35, optionally, in the embodiment of the present application, the escape hole 31 includes a first hole section 311 and a second hole section 312, the second hole section 312 is located on the side of the first hole section 311 that is closer to the active material application section 21, and the cross-sectional area of ​​the second hole section 312 gradually increases along the direction away from the first hole section 311. The active material application 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 tab portion 221 electrically connected to the current collector 211 and including a plurality of tab sheets 2211. The plurality of tab sheets 2211 gather at a position close to the current collector 211 to form a first converging portion 2212, and the plurality of tab sheets 2211 gather at a position away from the current collector 211 to connect to form a second converging portion 2213. When the first converging portion 2212 is connected to the second converging portion 2213 and the active material application portion 21, at least a portion of the first converging portion 2212 can be accommodated in the second hole step 312, and the second converging portion 2213 can be drilled in the first hole step 311.

[0281] In the above technical solution, the escape hole 31 is configured to include a second hole section 312 that gradually widens toward the active material-coated portion 21, thereby making it easier for the second hole section 312 to accommodate more first converging portions 2212, improving the compactness of the fit between the support 3 and the battery core assembly 2, reducing the overall volume of the battery cells 10, allowing more battery cells 10 to be accommodated in the battery 100, and improving the volumetric energy density of the battery 100. Furthermore, in the above technical solution, the first converging portion 2212 and the second converging portion 2213 have been described in detail in the above embodiments, and therefore will not be described again here.

[0282] In the embodiments of the present application, the support 3 may have an integral structure or a separate structure. FIG. 36 is a structural schematic diagram of an integral support 3 provided in some embodiments of the present application. Referring to FIG. 36, when the support 3 has an integral structure, the relief hole 31 is formed as a through-hole penetrating the support 3. Therefore, the support 3 with an integral structure is easy to process, has relatively high reliability, and facilitates assembly of the support 3 and the casing assembly 1, thereby improving assembly efficiency and fitting stability. It should be understood that the processing method for the support 3 can be specifically selected depending on the material of the support 3. For example, when the support 3 is made of an insulating plastic material, the support 3 with an integral structure can be obtained by injection molding.

[0283] 37 is a structural schematic diagram of a separate support 3 provided according to some embodiments of the present application. Referring to FIG. 37, when the support 3 has a separate structure, the support 3 includes a removable first support 33 and a second support 34. The first support 33 and the second support 34 are both elongated plate-like structures and can be removably connected to each other; for example, they can be fitted together by insertion or engagement, making assembly easy. In addition, the first support 33 has a semi-perforated structure on the side adjacent to the second support 34, and another semi-perforated structure with a matching shape is provided on the side adjacent to the first support 33. The semi-perforated structures of the first support 33 and the second support 34 together surround each other to form an annular relief hole 31. In other words, the relief hole 31 is defined between the first support 33 and the second support 34.

[0284] In the above technical proposal, an escape hole 31 is defined by the fitting of the first support 33 and the second support 34, and when assembling the support 3 and the battery core assembly 2, there is no need to pass the conductive part 22 from one end of the escape hole 31 to the other. Instead, the first support 33 and the second support 34 can be combined at the position of the conductive part 22 to sandwich the conductive part 22, and the escape hole 31 surrounds the conductive part 22, making it easier to assemble the support 3 and the battery core assembly 2 and improving assembly efficiency.

[0285] As an alternative technical solution, when the cross section of the escape hole 31 is elongated, the first support 33 and the second support 34 are arranged on both sides of the width of the escape hole 31; for example, when the width of the escape hole 31 is horizontal, the first support 33 and the second support 34 are located on the left and right sides of the escape hole 31, thereby facilitating the engagement of the first support 33 and the second support 34 with the conductive part 22.

[0286] Figure 38 is a schematic cross-sectional view of a battery core assembly 2 and a support 3 provided in some embodiments of the present application, and Figure 39 is an exploded structural view of a battery core assembly 2, a support 3, and a casing assembly 1 provided in some embodiments of the present application. Please refer to Figures 33, 38, and 39. In the embodiments of the present application, the configuration of the support 3 is not limited to these. For example, a casing guide surface 35 may be further installed on the edge of the support 3. The casing guide surface 35 may be an inclined or curved surface, and when projected orthogonally along the axial direction R of the first pole 12, the orthogonal projections of the active material application portion 21 are all located within the orthogonal projection range of the support 3, and the orthogonal projection range of the support 3 exceeds the orthogonal projection range of the active material application portion 21. During assembly, the support 3 and the battery core assembly 2 can be pre-assembled, and then this pre-assembled assembly is attached to the casing 11. During attachment, the support 3 is located at the front end of the active material application portion 21, i.e., the support 3 enters the casing 11 before the active material application portion 21. This makes it easier for the support 3 to enter the casing 11 using the casing entry guide surface 35. Furthermore, the relatively large projected area of ​​the support 3 provides protection for the active material application portion 21, reducing the likelihood of scratches between the active material application portion 21 and the casing 11, improving assembly efficiency and success rate. Furthermore, the contact area between the support 3 and the active material application portion 21 can be increased, reducing stress concentration problems and eliminating the need for other structural components.

[0287] 38 , in the embodiment of the present application, the battery cell 10 further includes an inner insulating member 4, which is located inside the casing 11 and surrounds the outside of the active material-coated portion 21, and the inner insulating member 4 is connected to the support 3. In the above embodiment, surrounding the outside of the active material-coated portion 21 with the inner insulating member 4 improves the insulation reliability between the active material-coated portion 21 and the casing 11, reduces or prevents corrosion of the casing 11 due to contact between the active material-coated portion 21 and the casing 11, reduces the problem of electrolyte leakage due to corrosion of the casing 11, and improves the reliability of the battery cell 10. Meanwhile, connecting the inner insulating member 4 to the support 3 makes it easier to fix the inner insulating member 4 and improves the reliability of the inner insulating member 4 surrounding the outside of the active material-coated portion 21.

[0288] 38 , in this embodiment, the support 3 includes a main body 36 and an extension 37. The main body 36 is located on the side of the active material-coated portion 21 closest to the first pole 12, and the extension 37 is connected to the main body 36 and located in the outer circumferential region of the active material-coated portion 21. For example, the extension 37 may be connected to the periphery of the main body 36 to form an annular extension structure connected to the main body 36, or it may extend from a local portion of the circumferential direction of the main body 36 to form a block structure protruding from the main body 36. The provision of the extension 37 restricts the position of the active material-coated portion 21 and alleviates the problem of corrosion caused by toner falling off the edge of the active material-coated portion 21 and overlapping the casing 11. The provision of the extension 37 also fixes the inner insulating member 4, improving the connection reliability between the inner insulating member 4 and the support 3 and providing relatively good insulation.

[0289] For example, referring to Figure 38, the main body portion 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 application portion 21, and the end of the inner insulating member 4 is fitted into the positioning groove 39, preventing the inner insulating member 4 from protruding from the edge of the main body portion 36. This allows the main body portion 36 to protect the inner insulating member 4 when it is inserted into the casing, and reduces the probability of scratches between the inner insulating member 4 and the casing 11.

[0290] Specifically, referring to FIG. 39, the inner insulating member 4 may be an integrated film, having main body portions 41 located on both sides of the active material application portion 21 in the thickness direction, and a connecting portion 42 connecting the two main body portions 41, the connecting portion 42 being located on the side of the active material application portion 21 away from the first pole 12, and the edge of the main body portion 41 on the side away from the connecting portion 42 extending to and connected to the extension portion 37, thereby providing relatively good insulating performance and facilitating connection.

[0291] In the embodiment of the present application, the specific method for installing the first pole 12 in the casing 11 is not limited, and may be, for example, riveting or welding, which will be described below.

[0292] For example, in some embodiments, Figure 40 is an exploded view of the first electrode post 12, casing 11, and seal pad provided by some embodiments of the present application, Figure 41 is an assembly view of the first electrode post 12, casing 11, and seal pad shown in Figure 40, and Figure 42 is a schematic structural view of the first electrode post 12 provided by some embodiments of the present application. Referring to Figures 40 to 42, the first electrode post 12 has an integral structure and may be riveted to the casing 11, which can improve the assembly efficiency of the first electrode post 12 and reduce the height of the first electrode post 12 protruding from the surface of the casing 11, which is advantageous for improving energy density and compactness.

[0293] Specifically, referring to Figures 40 to 42, the first pole 12 may include a stopper portion 1281 and a perforation portion 1282 before being riveted, and during assembly, the stopper portion 1281 stops inside the casing 11, the perforation portion 1282 is perforated in the mounting hole 113, and then the portion of the perforation portion 1282 located outside the casing 11 is riveted to form a flange portion 1283, and the flange portion 1283 is stopped outside the casing 11, thereby achieving mounting of the first pole 12.

[0294] 40 and 41, the casing assembly 1 may optionally include several seal pads, such as a first seal pad 191 and a second seal pad 192 shown in Fig. 40, fitted between the casing 11 and the first terminal post 12. Before riveting, the seal pads are assembled in place, and after riveting the first terminal post 12, the first terminal post 12 presses the seal pads to form a seal, thereby improving the sealing performance of the mating portion between the first terminal post 12 and the casing 11. The number, positions, and materials of the seal pads are not limited, and the material may be, for example, silicone, plastic, etc., and is not limited thereto.

[0295] 41, the length c of the flange portion 1283 may be 1 mm or more and the thickness d may be 2 mm or more to improve the rivet joint strength of the first terminal post 12. If the length c of the flange portion 1283 is less than 1 mm and / or the thickness d is less than 2 mm, the reliability of the first terminal post 12 and the casing 11 will be reduced under relatively strong vibration.

[0296] 43 and 44, the first pole 12 may have a separate structure and be welded to the casing 11. For example, the first pole 12 may include a first portion 1291 and a second portion 1292, at least a portion of the first portion 1291 being secured to the outside of the casing 11 and at least a portion of the second portion 1292 being secured to the inside of the casing 11. The first pole 12 may be attached by drilling at least one of the first portion 1291 and the second portion 1292 into the attachment hole 113 and welding (e.g., laser welding) the other portion to the attachment of the first pole 12.

[0297] In some alternative embodiments, FIG. 45 is an orthographic view of a battery cell 10 provided according to some embodiments of the present application, and FIG. 46 is an orthographic view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIG. 45 and FIG. 46, there are multiple first poles 12, and all of them are located on the same surface of the casing 11, which makes installation easier and improves assembly efficiency.

[0298] It should be noted that the arrangement method of the plurality of first poles 12 on the surface of the same side is not limited, and for example, when the cross section of the first poles 12 has an elongated structure, for example, when the length of the cross section is three times or more than the width of the cross section, such as an oval, racetrack, or rectangular shape, it is relatively well suited to the thin, flat casing 11. For example, the plurality of first poles 12 are all provided on one surface (referred to as the first wall surface 110) in the height direction of the casing 11, the length direction of each first pole 12 coincides with the length direction of the first wall surface 110 of the casing 11, and the plurality of first poles 12 are spaced apart along the length direction and / or width direction of the first wall surface 110.

[0299] 45, when the first wall surface 110 has two first poles 12, the two first poles 12 are spaced apart along the length direction of the first wall surface 110. Optionally, referring to FIG. 45, the portion of the first pole 12 located outside the casing 11 (referred to as "outside pole") is annular, and in the length direction of the first wall surface 110, the length a1 of the inner ring of the outside pole is equal to or greater than one-third of the length a0 of the first wall surface 110, and in the width direction of the first wall surface 110, the width b1 of the inner ring of the outside pole is equal to or greater than three-quarters of the width b0 of the first wall surface 110. This advantageously provides a relatively large area for the first pole 12 to electrically connect with the bus member, thereby facilitating further improvement of the current-passing capability of the first pole 12. Illustratively, the length a1 of the inner ring outside the pole is 50 mm or more, and the width b1 of the inner ring outside the pole is 30 mm or more.

[0300] 45, when the first wall 110 has two first poles 12 spaced apart along the length of the first wall 110, in some alternative embodiments, the first poles 12 include a portion (referred to as the pole interior) located within the casing 11, and the length of the pole interior along the length of the first wall 110 is at least one-third of the length of the first wall 110, and the width of the pole interior along the width of the first wall 110 is at least three-quarters of the width of the first wall 110. This advantageously provides a relatively large area for the first poles 12 to electrically connect with the conductive portion 22, further improving the current-passing capacity of the first poles 12. For example, the length of the pole interior is at least 50 mm, and the width of the pole interior is at least 30 mm.

[0301] 46, when the first wall surface 110 has four first poles 12, two of the first poles 12 are spaced apart along the width direction of the first wall surface 110 to form one pair, and a total of two pairs are spaced apart along the length direction of the first wall surface 110. Optionally, when combined with FIG. 46, the portion of the first poles 12 located outside the casing 11 (referred to as the "outside pole") is annular, and in the length direction of the first wall surface 110, the length a2 of the inner ring of the outside pole is equal to or greater than one-third of the length a0 of the first wall surface 110, and in the width direction of the first wall surface 110, the width b2 of the inner ring of the outside pole is equal to or greater than one-fifth of the width b0 of the first wall surface 110. This advantageously provides a relatively large area for the first poles 12 to be electrically connected to the bus members, thereby facilitating further improvement of the current passing capacity of the first poles 12. Illustratively, the length a2 of the inner ring outside the pole is 50 mm or more, and the width b2 of the inner ring outside the pole is 8 mm or more.

[0302] 46 , when the first wall surface 110 has four first poles 12, two of the first poles 12 are spaced apart along the width direction of the first wall surface 110 to form one pair, for a total of two pairs spaced apart along the length direction of the first wall surface 110, in some alternative embodiments, the first poles 12 include a portion located within the casing 11 (referred to as the pole interior), and the length of the pole interior along the length direction of the first wall surface 110 is ⅓ or more of the length of the first wall surface 110, and the width of the pole interior along the width direction of the first wall surface 110 is ⅕ or more of the width of the first wall surface 110. This advantageously provides a relatively large area for the first poles 12 to electrically connect with the conductive portion 22, facilitating further improvement of the current passing capacity of the first poles 12. For example, the length of the pole interior is 50 mm or more, and the width of the pole interior is 8 mm or more.

[0303] 45 and 46 , in some embodiments, a portion of the first electrode post 12 is located inside the casing 11 and a portion of the first electrode post 12 is located outside the casing 11, and the orthogonal projection area of ​​the portion of the first electrode post 12 located outside the casing 11 on the first wall surface 110 is 5% or more of the area of ​​the first wall surface 110. For example, the orthogonal projection area of ​​the portion of the first electrode post 12 located outside the casing 11 on the first wall surface 110 is 5%, 6%, 7%, 8%, 9%, 10% or more of the area of ​​the first wall surface 110. This increases the connection area between the first electrode post 12 and the bus members, which is advantageous for improving the effective current passage area between the first electrode post 12 and the bus members, and is advantageous for improving the charging speed of the battery cells 10.

[0304] Also, in some embodiments, Figure 47 is a cross-sectional view taken along line DD in Figure 46. Referring to Figure 47, in order to easily improve the volumetric energy density of the battery cell 10, the vertical height t1 from the portion of the first pole 12 protruding from the outer surface of the first wall surface 110 (referred to as the pole exterior) to the first wall surface 110 may be 3.2 mm or less, and the vertical height t2 from the portion of the first pole 12 protruding from the inner surface of the first wall surface 110 (referred to as the pole interior) to the first wall surface 110 may be 2 mm or less.

[0305] 48 is a schematic cross-sectional view of a casing assembly 1 provided according to some embodiments of the present application, FIG. 49 is a schematic cross-sectional view of the casing assembly 1 provided according to some embodiments of the present application, FIG. 50 is an orthographic view of a battery cell 10 provided according to some embodiments of the present application, FIG. 51 is a cross-sectional view taken along line E-E in FIG. 50, and FIG. 52 is a schematic local cross-sectional view of a battery cell 10 provided according to some embodiments of the present application. Referring to FIGS. 48 to 52, in the embodiment of the present application, the casing 11 specifically includes a casing body 111 and a casing cover 112, the casing body 111 has a rectangular ring structure and one or both ends are open, when one end is open, there is one casing cover 112 which is provided to cover the open position, and when both ends are open, there are two casing covers 112 which are provided to cover the open ends of the casing body 111, respectively.

[0306] In detail, when the casing 11 includes a casing body 111 and a casing cover 112 and one end of the casing body 111 is open, the casing body 111 may be a one-piece molded product, specifically an elongated rectangular structure. In this case, the first pole 12 may be provided on at least one of the casing body 111 and the casing cover 112. For example, referring to FIG. 48 , the first pole 12 may be provided on one end of the casing body 111 that is remote from the casing cover 112. When the battery cell 10 is used in a vibration environment, the amplitude of the connection between the casing body 111 and the casing cover 112 is relatively small, and the connection between the casing body 111 and the casing cover 112 is not likely to crack. This improves the reliability of the battery cell 10 and also allows the wall thickness of the casing body 111 to be thinner, thereby reducing costs, weight, and the size of the battery cell 10.

[0307] 48 again, as an alternative technical solution, when there are multiple first poles 12, all of the first poles 12 are provided at the end of the casing body 111 that is remote from the casing cover 112. As a result, when the battery cell 10 is used in a vibration environment, the amplitude of the connection between the casing body 111 and the casing cover 112 is relatively small, and the connection between the casing body 111 and the casing cover 112 is less likely to crack, thereby improving the reliability of the battery cell 10. Furthermore, the wall thickness e1 of the end wall of the casing body 111 that is remote from the casing cover 112 can be thinned to 2 mm or less, and the wall thickness e2 of the side wall connecting the end wall of the casing body 111 and the casing cover 112 can be thinned to 0.8 mm or less, thereby reducing costs, weight, and the size of the battery cell 10.

[0308] When the first electrode post 12 is provided with the first receiving groove 12110 corresponding to the mounting hole 113, the wall thickness of the portion of the first electrode post 12 located on the side of the first receiving groove 12110 away from the active material coated portion 21 becomes relatively thin, thereby making it possible to weld the conductive portion 22 and the first electrode post 12 from the outside of the casing 11. Referring to FIG. 48, the casing 11 includes a casing body 111 and a casing cover 112, and the casing cover 112 is provided on the opening of the casing body 111. When the first pole 12 is provided at the sealed end of the casing body 111, there is no need to worry about the problem of it being difficult to weld the conductive part 22 and the first pole 12 from inside the casing 11; the conductive part 22 and the first pole 12 can be welded from outside the casing 11. Therefore, by providing the first pole 12 at the sealed end of the casing body 111, the connection stability and reliability between the casing body 111 and the casing cover 112 can be improved.

[0309] When the second accommodating groove 12120 is formed in the first electrode post 12, welding between the conductive part 22 and the first electrode post 12 can be achieved from outside the casing 11 through the groove opening of the second accommodating groove 12120. Therefore, referring to FIG. 48, when the casing 11 includes a casing body 111 and a casing cover 112, and the casing cover 112 is provided at the open end of the casing body 111, even if the first electrode post 12 is provided at the sealed end of the casing body 111, there is no need to worry about the problem of it being difficult to weld the conductive part 22 and the first electrode post 12 from inside the casing 11. Since the conductive part 22 and the first electrode post 12 can be welded from outside the casing 11, by providing the first electrode post 12 at the sealed end of the casing body 111, the connection stability and reliability between the casing body 111 and the casing cover 112 can be improved.

[0310] 49, in other embodiments of the present application, all of the first poles 12 can be provided on the casing cover 112 as needed. This facilitates assembly of the first poles 12 and the casing cover 112, and is not limited to this embodiment.

[0311] 50 to 52, in the embodiment of the present application, when there are a plurality of first poles 12, the first poles 12 may be disposed on two surfaces on different sides of the casing 11. For example, a plurality of first poles 12 may be disposed on adjacent surfaces of the casing 11, or a plurality of first poles 12 may be disposed on opposing surfaces of the casing 11.

[0312] When first poles 12 are provided on opposite surfaces of the casing 11, conductive portions 22 can extend from positions adjacent to the first poles 12 on each side of the active material-coated portion 21, and the conductive portions 22 can fit and connect with the first poles 12 on the adjacent side, thereby alleviating the problem of the tab portions 221 being pulled by the first poles 12 on the same side and cracking the connection between the tab portions 221 and the active material-coated portion 21, and thereby improving the reliability of the battery cell 10. It should be noted that the first poles 12 on both sides may be identical or different, and the connection method between the first poles 12 on both sides and the conductive portions 22 may be identical or different and is not limited thereto.

[0313] Of course, in other embodiments of the present application, the first electrode post 12 may be disposed on the surface of the side of the casing 11 that has the largest area. For example, in some optional embodiments of the present application, the first electrode post 12 may be disposed on the top surface of the casing 11. For example, in some optional embodiments of the present application, the first electrode post 12 may be disposed on the bottom surface of the casing 11. When the first electrode post 12 is disposed on the bottom surface of the casing 11, the receiving portion 121 can be used to receive the electrolyte, thereby improving the cycle life of the battery cell 10. Furthermore, when the first electrode post 12 is disposed on the bottom surface of the casing 11 and the support 3 is disposed at the bottom of the active material-coated portion 21, the contact area between the support 3 and the active material-coated portion 21 can be increased, thereby alleviating stress concentration problems and eliminating the need for other supporting structural members.

[0314] 53 is a structural schematic diagram of a casing cover 112 provided in some embodiments of the present application. Referring to FIG. 53, in the embodiments of the present application, the casing 11 has a pressure release portion 16. The specific configuration of the pressure release portion 16 is not limited, and may be, for example, an explosion-proof valve or a weak portion, which is used to release pressure when the pressure inside the battery cell 10 is relatively high, thereby improving the reliability of the battery cell 10.

[0315] Alternatively, the pressure relief portion 16 and the first pole 12 may be located on the same surface of the casing 11, which facilitates processing and assembly. Alternatively, the pressure relief portion 16 and the first pole 12 may be located on opposite surfaces of the casing 11, which can save space, increase the volume of the first pole 12, and reduce the adverse effect of the pressure relief portion 16 on the pole 12 when releasing pressure.

[0316] 48 and 53, in the present embodiment, the pressure relief portion 16 can be provided on the casing cover 112, if necessary. The casing cover 112 does not need to mount the first electrode post 12, and the connection point between the casing cover 112 and the casing 11 is less susceptible to vibrations during the charging and discharging of the battery cell 10 and is less likely to crack. Therefore, the casing cover 112 can be relatively thin, which facilitates the processing and manufacturing of the pressure relief portion 16. For example, to fully improve the manufacturability of the battery cell 10, the pressure relief portion 16 can be easily formed by an integrally molded notch on the casing cover 112. It should be noted that in this embodiment, the first electrode post 12 can be provided on either the casing body 111 or the casing cover 112, and this is not limiting. For example, the pressure relief portion 16 can be integrally molded with the casing cover 112, which facilitates processing, simplifies assembly, improves production efficiency, and reduces costs.

[0317] 3 to 5, 18, and 23 to 24, a battery cell 10 according to a specific embodiment of the present invention will be described.

[0318] In the embodiment of the present application, the battery cell 10 has a rectangular parallelepiped shape, and the height direction of the battery cell 10 is a first direction Z, the length direction of the battery cell 10 is a second direction X, and the thickness direction of the battery cell 10 is a third direction Y. The battery cell 10 includes a casing 11, which includes a casing body 111 and a casing cover 112. The casing body 111 has a rectangular ring structure, one end of the casing body 111 along the first direction Z is open and the other end along the first direction Z is closed, and the casing cover 112 is installed to cover the open position of the casing body 111.

[0319] At the same time, two poles are provided at the sealed end of the casing body 111 along the first direction Z, and the two poles are spaced apart along the second direction X, and are respectively a positive pole and a negative pole. Each of the two poles is a first pole 12 having an accommodating portion 121, and the accommodating portion 121 includes a second accommodating groove 12120. Specifically, the first pole 12 includes a second end wall 12121 and a second side wall 12123. The second end wall 12121 is located on the side of the second side wall 12123 that is close to the casing cover 112, and the second end wall 12121 and the second side wall 12123 are attached. The first pole 12 surrounds the second end wall 12121 to form a second accommodating groove 12120, and the surface of the first pole 12 facing away from the casing cover 112 is the pole outer end surface 123, and the groove opening of the second accommodating groove 12120 is formed in the pole outer end surface 123. A first through hole 12130 is opened in the second end wall 12121, and the first through hole 12130 is located at a position close to the second side wall 12123 of the second end wall 12121.

[0320] The battery cell 10 also includes a battery core assembly 2, which includes an active material application portion 21 and a tab portion 221. The active material application portion 21 is housed in the casing 11, and the tab portion 221 passes through the first through-hole 12130 and extends into the second accommodating groove 12120 and is welded to the second end wall 12121, electrically connecting the active material application portion 21 and the first pole 12 via the tab portion 221.

[0321] Furthermore, the first cover plate 13 is fitted into the opening of the second accommodating groove 12120, so that after welding the tab portion 221 to the second end wall 12121 is completed, the opening of the second accommodating groove 12120 can be sealed by fitting the first cover plate 13 to the first pole 12. The first cover plate 13 is welded to the first pole 12 to form an electrical connection. Thereafter, if a bus member is used to electrically connect the battery cells 10, the bus member may be welded to the first cover plate 13 to establish electrical connection with the first pole 12.

[0322] In the above technical solution, on the one hand, by providing the second receiving groove 12120 in the first pole 12, the weight of the first pole 12 can be reduced to a certain extent, and the weight energy density of the battery cell 10 and the battery 100 can be improved. On the other hand, since the groove opening of the second receiving groove 12120 is formed on the pole outer end surface 123, and the pole outer end surface 123 is the surface of the first pole 12 away from the active material coated portion 21, the second receiving groove 12120 can be formed on the active material coated portion 21. The tab portion 221 can be opened in a direction away from the fabric portion 21, and by accommodating at least a portion of the tab portion 221 in the second accommodating groove 12120, the tab portion 221 can be easily accommodated and organized through the groove opening of the second accommodating groove 12120, and the welding operation between the tab portion 221 and the first pole 12 can be easily performed through the groove opening of the second accommodating groove 12120, thereby reducing the difficulty of producing the battery cell 10 and improving the production efficiency of the battery cell 10.

[0323] Furthermore, since the tab portion 221 and the first pole 12 can be welded from outside the casing 11, the first pole 12 may be provided at the sealed end of the casing 111. In this way, when the battery cell 10 is used in a vibration environment, the amplitude of the connection between the casing body 111 and the casing cover 112 is relatively small, and cracks are less likely to occur at the connection between the casing body 111 and the casing cover 112. This improves the reliability of the battery cell 10 and allows the wall thickness of the casing body 111 to be thinner, which reduces costs, reduces weight, and is advantageous for achieving a more compact battery cell 10.

[0324] At the same time, because the second accommodating groove 12120 is connected to the inside of the casing 11 through the first through-hole 12130, the second accommodating groove 12120 can also be used as a buffering and temporary storage structure for the electrolyte, allowing more electrolyte to be accommodated in the casing 11. Since the electrolyte is consumed during the charging and discharging process of the battery cell 10, the service life of the battery cell 10 can be extended when there is more electrolyte. Furthermore, because the second accommodating groove 12120 is connected to the inside of the casing 11 through the first through-hole 12130, the second accommodating groove 12120 can also be used as a buffering structure for the gas generated inside the battery core assembly 2, reducing the expansion of the battery cell 10 and improving the reliability and stability of the battery cell 10.

[0325] According to some embodiments of the present application, the present application further provides a battery 100 including the battery cell 10 of any one of the above embodiments.

[0326] In the above technical solution, the battery cell 10 is installed in the battery 100, and the first pole 12 of the battery cell 10 is provided with the receiving portion 121, thereby reducing the weight of the first pole 12 to some extent and improving the weight energy density of the battery cell 10 and the battery 100. Meanwhile, by accommodating at least a portion of the conductive portion 22 in the receiving portion 121, it occupies space within the first pole 12, which is advantageous to improving the volumetric energy density of the battery cell 10, or by reducing the space occupied by the battery cell 10 itself, more battery cells can be accommodated in the same volume of the battery 100, which is advantageous to improving the volumetric energy density of the battery 100. Furthermore, by accommodating at least a portion of the conductive portion 22 in the receiving portion 121, it is possible to reduce the redundancy of the conductive portion 22 within the casing 11 to some extent and reduce the probability of a short circuit between the conductive portion 22 and the active material-coated portion 21, which further improves the operational reliability and stability of the battery cell 10 and the battery 100. According to some embodiments of the present application, the present application further provides an electric device 1000 including the battery 100 of the above embodiments, wherein the battery 100 is used to supply electric energy to the electric device 1000.

[0327] In the above technical solution, since the battery 100 is installed in the electric device 1000, the energy density of the battery 100 can be increased, which is beneficial to extending the service life of the electric device 1000, and the operational reliability and stability of the battery 100 can be improved, which is beneficial to extending the service life of the electric device 1000. It should be understood that if the electric device 1000 is a vehicle, the extended service life of the battery 100 can be beneficial to extending the driving range of the vehicle.

[0328] It should be noted that, unless there is a contradiction, the embodiments and features of the embodiments of the present application can be combined with each other.

[0329] The above is merely a preferred embodiment of the present application and does not limit the present application, and various modifications and variations of the present application may be made by those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the scope of the spirit and principles of the present application are also included in the scope of the claims of the present application.

Claims

1. A battery cell (10), a casing assembly (1) including a casing (11) and a first pole (12) installed in the casing (11), the first pole (12) having a receiving section (121) installed therein; a battery core assembly (2) including an active material coated portion (21) housed in the casing (11) and a conductive portion (22) for electrically connecting the active material coated portion (21) and the first pole (12); At least a part of the conductive portion (22) is accommodated in the accommodation portion (121). Battery cell (10).

2. The accommodating portion (121) has a first accommodating groove (12110), the surface of the first pole (12) facing the active material coated portion (21) is the pole inner end face (122), the groove opening of the first accommodating groove (12110) is formed in the pole inner end face (122), and at least a part of the conductive portion (22) is accommodated in the first accommodating groove (12110). The battery cell (10) of claim 1.

3. The casing (11) has a mounting hole (113), the first pole (12) is mounted in the mounting hole (113), and the depth H1 of the first accommodating groove (12110) along the axial direction of the first pole (12) is equal to or greater than the minimum distance H2 from the pole inner end surface (122) to the mounting hole (113). The battery cell (10) of claim 2.

4. The first electrode pillar (12) includes a first end wall (12111) and a first side wall (12113), the first end wall (12111) is located on the side of the first side wall (12113) away from the active material application portion (21), the first end wall (12111) and the first side wall (12113) surround each other to form the first accommodating groove (12110), and the electrical connection position between the conductive portion (22) and the first electrode pillar (12) is located on the first end wall (12111) and / or the first side wall (12113). A battery cell (10) according to claim 2 or 3.

5. The first end wall (12111) has a first recessed groove (12112), and at least a part of the electrical connection position between the conductive portion (22) and the first end wall (12111) is located within the first recessed groove (12112). The battery cell (10) of claim 4.

6. The first electrode post (12) has a first recessed groove (126), and the surface of the first electrode post (12) away from the active material coated portion (21) is an outer end face (123) of the electrode post, and the groove opening of the first recessed groove (126) is formed in the outer end face (123) of the electrode post. The battery cell (10) according to any one of claims 2 to 5.

7. The casing assembly (1) further includes a groove cover (7), which is attached to the pole post (12) and seals and caps the opening of the first groove (126). The battery cell (10) of claim 6.

8. The active material application 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 tab portion (221) electrically connected to the current collector (211), the tab portion (221) includes a plurality of tab sheets (2211), the plurality of tab sheets (2211) gather at a position close to the current collector (211) to form a first converging portion (2212), the plurality of tab sheets (2211) gather at a position away from the current collector (211) to be connected to form a second converging portion (2213), the first converging portion (2212) connects the second converging portion (2213) and the active material application portion (21), and at least a portion of the second converging portion (2213) is accommodated in the first accommodation groove (12110). The battery cell (10) according to any one of claims 2 to 7.

9. At least a portion of the first converging portion (2212) is accommodated within the first accommodating groove (12110); The battery cell (10) of claim 8.

10. The conductive portion (22) further includes an adapter sheet (222), the adapter sheet (222) is connected to the second converging portion (2213), the conductive portion (22) is electrically connected to the first pole (12) via the adapter sheet (222), and at least a portion of the adapter sheet (222) is accommodated in the first accommodating groove (12110). A battery cell (10) according to claim 8 or 9.

11. The active material application section (21) includes a current collector (211) and an active material layer (212) provided on the current collector (211), and the conductive section (22) includes a tab section (221) and an adapter sheet (222), and the tab section (221) includes a tab section (221) including a plurality of tab sheets (2211) electrically connected to the current collector (211), and the plurality of tab sheets (2211) are gathered in a position close to the current collector (211). The tab sheets (2211) are connected together to form a first converging portion (2212), and a plurality of the tab sheets (2211) are gathered at a position away from the current collector (211) and connected to form a second converging portion (2213), and the adapter sheet (222) is electrically connected to the second converging portion (2213), and at least a portion of the adapter sheet (222) is accommodated in the first accommodating groove (12110) and electrically connected to the first pole (12). The battery cell (10) according to any one of claims 2 to 7.

12. The accommodating portion (121) has a second accommodating groove (12120), the surface of the first pole (12) away from the active material coated portion (21) is the pole outer end face (123), the groove opening of the second accommodating groove (12120) is formed in the pole outer end face (123), the second accommodating groove (12120) communicates with the inside of the casing (11) via a first through hole (12130), the conductive portion (22) is drilled in the first through hole (12130), and at least a portion of the conductive portion (22) is accommodated in the second accommodating groove (12120). The battery cell (10) of claim 1.

13. The electrical connection position between the conductive portion (22) and the first electrode post (12) is located on the hole wall of the first through hole (12130) formed in the first electrode post (12). The battery cell (10) of claim 12.

14. The first electrode post (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) that is close to the active material coating portion (21), the second end wall (12121) and the second side wall (12123) surround each other to form the second accommodating groove (12120), the first through hole (12130) is opened in the second end wall (12121), and the electrical connection position between the conductive portion (22) and the first electrode post (12) is located in the second end wall (12121) and / or the second side wall (12123). The battery cell (10) of claim 12.

15. The second end wall (12121) has a second recessed groove (12122), and at least a part of the electrical connection position between the conductive portion (22) and the second end wall (12121) is located within the second recessed groove (12122). The battery cell (10) of claim 14.

16. The casing (11) has a mounting hole (113), the first pole (12) is mounted in the mounting hole (113), and the depth H3 of the second accommodating groove (12120) along the axial direction of the first pole (12) is equal to or greater than the minimum distance H4 from the pole outer end face (123) to the mounting hole (113). The battery cell (10) according to any one of claims 12 to 15.

17. The casing assembly (1) further includes a first cover plate (13), which is fitted onto the first pole (12) and seals the opening of the second receiving groove (12120), and the first cover plate (13) is electrically connected to the first pole (12). A battery cell (10) according to any one of claims 12 to 16.

18. 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 fitted to the first pole (12) and electrically connected thereto, and the second conductive member (132) is fitted to the first conductive member (131) and electrically connected thereto.

18. The battery cell (10) of claim 17.

19. The first conductive member (131) has a second groove (1311), the second conductive member (132) is fitted into the second groove (1311), and the groove opening of the second groove (1311) is formed on the surface of the first conductive member (131) on the side away from the second accommodating groove (12120) so that the second conductive member (132) is exposed from the groove opening of the second groove (1311).

20. The battery cell (10) of claim 18.

20. The first cover plate (13) is fitted into the groove opening of the second receiving groove (12120). The battery cell (10) according to any one of claims 17 to 19.

21. The wall surface on which the groove opening of the second receiving groove (12120) of the first pole post (12) is formed is a guide inclined surface (12126), and the guide inclined surface (12126) is used to guide the fitting of the first cover plate (13) with the groove opening of the second receiving groove (12120). The battery cell (10) of claim 20.

22. The second receiving groove (12120) includes a first groove step (12124) and a second groove step (12125) located on the side of the first groove step (12124) close to the pole outer end surface (123), the cross-sectional area of ​​the second groove step (12125) is larger than the cross-sectional area of ​​the first groove step (12124), so as to form a step surface (12127) between the first groove step (12124) and the second groove step (12125), and the first cover plate (13) is fitted into the second groove step (12125) and supported by the step surface (12127).

22. A battery cell (10) according to claim 20 or 21.

23. The first cover plate (13) has a stress relief groove (133), and the stress relief groove (133) is located in the outer peripheral region of the first cover plate (13). A battery cell (10) according to any one of claims 17 to 22.

24. The casing assembly (1) further includes a second cover plate (14), which is provided to cover the outside of the conductive portion (22) located in the first through hole (12130) and the second accommodating groove (12120). A battery cell (10) according to any one of claims 12 to 23.

25. The first pole (12) includes a first pole portion (124) and a second pole portion (125) made of different materials and electrically connected, the second pole portion (125) is located on the side of the first pole portion (124) away from the active material coated portion (21), the accommodating portion (121) is installed on the first pole portion (124) or on the first pole portion (124) and the second pole portion (125), and the conductive portion (22) is electrically connected to the first pole portion (124). A battery cell (10) according to any one of claims 1 to 24.

26. The active material application 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 tab portion (221) electrically connected to the current collector (211), the tab portion (221) includes a plurality of tab sheets (2211), the plurality of tab sheets (2211) gather at a position close to the current collector (211) to form a first converging portion (2212), the plurality of tab sheets (2211) gather at a position away from the current collector (211) to be connected to form a second converging portion (2213), the first converging portion (2212) connects the second converging portion (2213) and the active material application portion (21), and at least a portion of the second converging portion (2213) is accommodated in the second accommodation groove (12120). A battery cell (10) according to any one of claims 12 to 24.

27. The accommodating portion (121) further has a third accommodating groove (12140), the surface of the first pole (12) facing the active material application portion (21) is the pole inner end face (122), the third accommodating groove (12140) is located on the side of the second accommodating groove (12120) close to the active material application portion (21), and the groove opening of the third accommodating groove (12140) is formed in the pole inner end face (122), the third accommodating groove (12140) and the second accommodating groove (12120) are connected via the first through hole (12130), and at least a portion of the first converging portion (2212) is accommodated in the third accommodating groove (12140).

27. The battery cell (10) of claim 26.

28. The conductive portion (22) further includes an adapter sheet (222), the adapter sheet (222) is connected to the second converging portion (2213), the conductive portion (22) is electrically connected to the first pole (12) via the adapter sheet (222), and at least a portion of the adapter sheet (222) is accommodated in the second accommodating groove (12120).

28. A battery cell (10) according to claim 26 or 27.

29. The active material application section (21) includes a current collector (211) and an active material layer (212) provided on the current collector (211), the conductive section (22) includes a tab section (221) and an adapter sheet (222), the tab section (221) includes a plurality of tab sheets (2211) electrically connected to the current collector (211), and the plurality of tab sheets (2211) are gathered in a position close to the current collector (211) to form a first a converging portion (2212), and a plurality of the tab sheets (2211) are gathered and connected at a position away from the current collector (211) to form a second converging portion (2213), and the adapter sheet (222) is electrically connected to the second converging portion (2213), and at least a portion of the adapter sheet (222) is accommodated in the second accommodating groove (12120) and electrically connected to the first pole (12); A battery cell (10) according to any one of claims 12 to 24.

30. The accommodating portion (121) has a fourth accommodating groove (12150), the surface of the first pole (12) away from the active material coated portion (21) is the pole outer end surface (123), the groove opening of the fourth accommodating groove (12150) is formed in the pole outer end surface (123), the fourth accommodating groove (12150) is connected to the inside of the casing (11) via a second through hole (12160), the conductive portion (22) is drilled in the second through hole (12160), and the electrical connection position between the conductive portion (22) and the pole (12) is located on the hole wall of the second through hole (12160) formed in the first pole (12). The battery cell (10) of claim 1.

31. The battery further includes a support (3) located within the casing (11) and on a side of the active material coated portion (21) that is close to the first pole (12), the support (3) having an escape hole (31) for avoiding the conductive portion (22), and the conductive portion (22) is adapted to extend through the escape hole (31) to a side of the support (3) that is away from the active material coated portion (21). The battery cell (10) according to any one of claims 1 to 7, 12 to 25, or 30.

32. The support (3) is provided with a guide portion (32), the guide portion (32) surrounding the relief hole (31) forms at least a part of the relief hole (31), and at least a part of the guide portion (32) extends into the accommodation portion (121).

32. The battery cell (10) of claim 31.

33. The support (3) is provided with a third recess (38), and at least a portion of the first pole (12) located inside the casing (11) is accommodated in the third recess (38).

33. A battery cell (10) according to claim 31 or 32.

34. The relief hole (31) includes a first hole section (311) and a second hole section (312), the second hole section (312) is located on the side of the first hole section (311) that is close to the active material application section (21), and the cross-sectional area of ​​the second hole section (312) gradually increases in a direction away from the first hole section (311), the active material application section (21) includes a current collector (211) and an active material layer (212) provided on the current collector (211), the conductive section (22) includes a tab section (221) electrically connected to the current collector (211), and the tab section (221) is provided with a plurality of tab sleeves. a plurality of tab sheets (2211) gathered at a position close to the current collector (211) to form a first converging portion (2212), and a plurality of tab sheets (2211) gathered at a position away from the current collector (211) to be connected to form a second converging portion (2213), the first converging portion (2212) connects the second converging portion (2213) and the active material application portion (21), at least a portion of the first converging portion (2212) is accommodated in the second hole step (312), and the second converging portion (2213) is drilled in the first hole step (311); A battery cell (10) according to any one of claims 31 to 33.

35. The support (3) is an integral structure, or the support (3) is a separate and removable first support (33) and second support (34), and the relief hole (31) is defined between the first support (33) and the second support (34). The battery cell (10) according to any one of claims 31 to 34.

36. The battery further includes an inner insulating member (4) located within the casing (11), surrounding the outside of the active material application portion (21), and connected to a support (3). A battery cell (10) according to any one of claims 31 to 35.

37. The casing assembly (1) includes a plurality of poles, at least one of the poles being the first pole (12); A battery cell (10) according to any one of claims 1 to 36.

38. The casing (11) has a pressure release part (16), and the pressure release part (16) and the pole are located on the same surface of the casing (11), or the pressure release part (16) and the pole are respectively located on two surfaces on different sides of the casing (11).

38. The battery cell (10) of claim 37.

39. The casing (11) has a pressure release section (16), the casing (11) includes a casing body (111) and a casing cover (112), one end of the casing body (111) is open, the casing cover (112) is provided at the open end of the casing body (111), and the pressure release section (16) is provided at the casing cover (112). A battery cell (10) according to any one of claims 1 to 38.

40. A battery cell (10) according to any one of claims 1 to 39. Battery (100).

41. 41. The battery (100) of claim 40, Electrical device (1000).

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