Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell and an electrode assembly; the shell comprises a mounting wall provided with an electrode terminal; the electrode assembly is accommodated in the shell and comprises a main body and a tab, the tab being connected to one end of the main body facing the mounting wall in a first direction; the mounting wall has a first inner surface facing the electrode assembly, the first inner surface is formed with a recess, the recess extends to at least one edge of the first inner surface, and at least part of the tab is accommodated in the recess. The space inside the shell can be fully utilized, the volume of the battery monomer is reduced, the energy density of the battery monomer is improved, the space of the recess is larger, the tab can be accommodated in the recess to a larger extent or a tab with a larger size can be accommodated in the recess, the tab occupies less space outside the recess inside the shell, and the energy density of the battery monomer is further improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in new energy vehicles, electronic devices, and other fields. As the demand for batteries increases, higher requirements are being placed on their energy density. Utility Model Content

[0003] This application provides a battery cell, a battery device, and an electrical device that can improve the energy density of the battery cell.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a housing and an electrode assembly; the housing includes a mounting wall, the mounting wall being provided with electrode terminals; the electrode assembly is housed within the housing, the electrode assembly including a main body and a tab, the tab being connected to one end of the main body facing the mounting wall along a first direction and electrically connected to the electrode terminals; wherein, the mounting wall has a first inner surface facing the electrode assembly, the first inner surface forming a recess, the recess extending to at least one edge of the first inner surface, and at least a portion of the tab being housed in the recess.

[0005] In the above technical solution, by providing a recess on the first inner surface of the mounting wall facing the electrode assembly, at least a portion of the tab is accommodated within the recess. This fully utilizes the space inside the casing, which helps to reduce the volume of the battery cell and increase its energy density. The recess extends to at least one edge of the first inner surface, making the recess larger and allowing for greater accommodation of the tab or enabling the recess to accommodate larger tabs. This reduces the space occupied by the tab outside the recess inside the casing, further improving the energy density of the battery cell.

[0006] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion, wherein a recess is formed on the side of the second portion facing the electrode assembly; the first portion and the second portion are arranged along a second direction and along a third direction, the first portion and the second portion have the same size, and the first direction, the second direction and the third direction are perpendicular to each other.

[0007] In the above technical solution, by arranging the first part and the second part along the second direction, and by having the same size in the third direction, it is easy to make the edges of the first part and the second part flush in the third direction, thereby facilitating the connection between the mounting wall and other wall parts of the housing.

[0008] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion, the second portion having a recessed portion on the side facing the electrode assembly; the first portion and the second portion are arranged along a second direction and along a third direction, at least one edge of the first portion and the second portion are flush, and the first direction, the second direction and the third direction are perpendicular to each other.

[0009] In the above technical solution, by having at least one edge of the first part and the second part flush, it is convenient to connect the mounting wall and other wall parts of the housing.

[0010] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion, the second portion protruding from the surface of the first portion opposite to the electrode assembly along the first direction, and a recess being formed on the side of the second portion facing the electrode assembly.

[0011] In the above technical solution, by having the second part protrude from the surface of the first part away from the electrode assembly, and a recessed part formed on the side of the second part facing the electrode assembly, the recessed part can be formed without reducing the thickness of the second part, which is beneficial to the uniform wall thickness of the mounting wall, resulting in better overall strength of the mounting wall and thus improving the mechanical properties of the shell.

[0012] In some embodiments of the first aspect of this application, the battery cell further includes electrode terminals disposed in the first portion.

[0013] In the above technical solution, by setting the electrode terminal in the first part, the electrode terminal and the tab can overlap in a certain direction perpendicular to the first direction. The electrode terminal can make full use of the space formed by the height difference between the first part and the second part in the first direction, which is beneficial to reduce the size of the battery cell and increase the energy density of the battery cell.

[0014] In some embodiments of the first aspect of this application, along the first direction, the second portion protrudes from the surface of the electrode terminal away from the electrode assembly.

[0015] In the above technical solution, by having the second part protrude from the surface of the electrode terminal away from the electrode assembly along the first direction, a space is formed between the portion of the second part that protrudes from the surface of the electrode terminal away from the electrode assembly and the electrode terminal. This space can be used to accommodate other structures (such as busbar components) connected to the electrode terminal, making it more convenient to connect the battery cell to other structures, reducing the risk of interference when connecting the battery cell to other structures, and improving the stability of the electrical connection.

[0016] In some embodiments of the first aspect of this application, along the first direction, the second portion protrudes from the surface of the electrode terminal away from the electrode assembly by a dimension L, 0.1mm≤L≤5mm.

[0017] In the above technical solution, if the second part protrudes beyond the electrode terminal's surface away from the electrode assembly along the first direction by a size greater than or equal to 0.1 mm, the space formed between the portion of the second part protruding beyond the electrode terminal's surface and the electrode terminal is relatively large. This provides ample space for other structures connected to the electrode terminal, facilitating electrical connections between the electrode terminal and other structures. This makes electrical connections between the battery cell and other structures more convenient, reduces the risk of interference during connections, improves the stability of electrical connections, and makes the overall structure more compact after the battery cell is connected to other structures. If the second part protrudes beyond the electrode terminal's surface away from the electrode assembly along the first direction by a size less than or equal to 5 mm, controlling the maximum size of the second part protruding beyond the electrode terminal's surface along the first direction helps reduce the size of the battery cell in the first direction, thereby reducing the battery cell's volume and increasing its energy density. Therefore, 0.1 mm ≤ L ≤ 5 mm not only facilitates electrical connections between the battery cell and other structures but also contributes to a higher energy density for the battery cell.

[0018] In some embodiments of the first aspect of this application, when viewed along at least one direction perpendicular to the first direction, at least a portion of the tab overlaps with at least a portion of the electrode terminal.

[0019] In the above technical solution, when viewed along at least one direction perpendicular to the first direction, at least a portion of the tab overlaps with at least a portion of the electrode terminal, so that the electrode terminal can make full use of the space formed by the height difference between the first portion and the second portion in the first direction, which is beneficial to reduce the size of the battery cell and increase the energy density of the battery cell.

[0020] In some embodiments of the first aspect of this application, the housing includes an end wall and a side wall. Along the first direction, the end wall and the mounting wall are disposed opposite to each other. The side wall includes a body portion and a protrusion. The body portion surrounds the outer periphery of the end wall. Along the first direction, one end of the body portion is connected to the end wall, and the other end of the body portion is connected to the protrusion. The protrusion protrudes from one end of the body portion away from the end wall. A portion of the body portion is directly connected to the first portion, and the protrusion is directly connected to the second portion.

[0021] In the above technical solution, a protruding part is provided at one end of the main body of the side wall away from the end wall. The part of the main body is directly connected to the first part, and the protruding part is directly connected to the second part. The height position of the area of ​​the side wall connected to the first part in the first direction corresponds to the first part. The height position of the area of ​​the side wall connected to the second part in the first direction corresponds to the second part, which facilitates the connection between the first part and the second part and the side wall, thereby facilitating the connection between the wall and the side wall.

[0022] In some embodiments of the first aspect of this application, the housing further includes an end wall and a side wall, the side wall surrounding the outer periphery of the end wall, one end of the side wall being connected to the end wall, and the other end of the side wall forming an opening, the mounting wall sealing the opening; the second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, the first wall portion being further away from the main body portion along the first direction, the first wall portion being connected to the side wall to form a first connecting portion, the first connecting portion being further away from the main body portion along the first direction than the tab.

[0023] In the above technical solution, the first connecting portion formed by the connection between the sidewall and the first wall is farther away from the main body than the tab. Therefore, when viewed along any direction perpendicular to the first direction, the first connecting portion and the tab do not overlap. Compared to solutions where the first connecting portion and the tab at least partially overlap when viewed along at least one direction perpendicular to the first direction, this solution has a greater distance between the first connecting portion and the tab. This reduces the impact of the high temperature generated at the tab during charging and discharging on the first connecting portion, thereby alleviating the problem of reduced connection strength and toughness at the first connecting portion due to the high temperature at the tab. This is beneficial for improving the connection stability between the first wall and the sidewall, thus improving the reliability of the battery cell. Since the first connecting portion is farther away from the main body than the tab along the first direction, the increased distance between the first connecting portion and the main body means that the first connecting portion is less affected by changes in the internal pressure of the battery cell. This alleviates the problem of fatigue failure at the first connecting portion caused by changes in the internal pressure of the battery cell, improving the reliability of the first connecting portion, and further improving the reliability of the battery cell.

[0024] In some embodiments of the first aspect of this application, the battery cell further includes an electrode terminal disposed in the first portion, and the battery cell further includes a current collector connecting the tab and the electrode terminal. At least a portion of the current collector is located within the recess and is connected to the tab to form a second connection portion. Along the first direction, the first connection portion is further away from the main body portion than the second connection portion.

[0025] In the above technical solution, the tab and electrode terminal are connected by a current collector, which facilitates the electrical connection between the tab and electrode terminal located in the recess. A portion of the current collector is located in the recess and connected to the tab to form a second connection portion. By positioning the first connection portion further away from the main body along the first direction, the first and second connection portions do not overlap when viewed from any direction perpendicular to the first direction, and the first connection portion and the tab do not overlap at any position. Compared to solutions where the first and second connection portions at least partially overlap when viewed from at least one direction perpendicular to the first direction, and solutions where the first connection portion and the tab at least partially overlap, this solution has a greater distance between the first and second connection portions. This reduces the impact of high temperatures generated at the tab or second connection portion during charging and discharging on the first connection portion, thereby alleviating the problem of reduced connection strength and toughness at the first connection portion caused by high temperatures generated at the tab or second connection portion. This is beneficial for improving the connection stability between the first wall and the casing, thereby improving the reliability of the battery cell. Since the first connecting portion is farther away from the main body than the second connecting portion along the first direction, the distance between the first connecting portion and the main body of the electrode assembly is increased. The first connecting portion is less affected by the internal pressure changes of the battery cell, thereby alleviating the problem of fatigue failure at the first connecting portion caused by the internal pressure changes of the battery cell, improving the reliability of the first connecting portion, and further improving the reliability of the battery cell.

[0026] In some embodiments of the first aspect of this application, the current collecting member includes a first segment arranged along the first direction with the electrode tab, the first segment being connected to the electrode tab to form a second connecting portion, the first segment being located on the side of the electrode tab away from the main body along the first direction, and the first connecting portion being further away from the main body than the first segment.

[0027] In the above technical solution, the first segment, located on the side of the tab away from the main body, facilitates the installation of the current collector and the connection between the current collector and the tab to form the first connection portion. During charging and discharging, the first segment connecting the current collector and the tab also experiences high temperatures. With the first segment of the current collector located on the side of the tab away from the main body, the first connection portion is further away from the main body than the first segment. Therefore, the first connection portion is less affected by the high temperatures of the tab and the current collector, thus mitigating the problem of reduced connection strength and toughness at the connection point caused by high temperatures at the tab and current collector connection. This improves the connection stability between the first wall and the casing, thereby enhancing the reliability of the battery cell. Furthermore, because the first connection portion is further away from the main body than the first segment along the first direction, it is less affected by changes in internal pressure within the battery cell. This mitigates the problem of fatigue failure at the first connection portion caused by changes in internal pressure within the battery cell, improving the reliability of the first connection portion and further enhancing the reliability of the battery cell.

[0028] In some embodiments of the first aspect of this application, the distance between the first connecting portion and the second connecting portion along the first direction is H, where H > 0.

[0029] In the above technical solution, since the distance between the first connecting part and the second connecting part in the first direction is greater than 0, any position of the first connecting part is farther away from the main body than any position of the second connecting part in the first direction. This results in a larger straight-line distance between the first and second connecting parts, reducing the impact of high temperatures generated at the tabs or second connecting parts during charging and discharging on the first connecting part. This alleviates the problem of reduced connection strength and toughness at the first connecting part caused by high temperatures at the tabs or second connecting parts, which is beneficial to improving the connection stability between the first wall and the casing, thereby improving the reliability of the battery cell. Furthermore, the larger straight-line distance between the first and second connecting parts also makes the first connecting part less affected by changes in internal pressure within the battery cell, thus mitigating the problem of fatigue failure at the first connecting part caused by changes in internal pressure within the battery cell, improving the reliability of the first connecting part, and further improving the reliability of the battery cell.

[0030] In some embodiments of the first aspect of this application, H ≥ 1 mm.

[0031] In the above technical solution, since the distance between the first connecting part and the second connecting part in the first direction is greater than or equal to 1 mm, any position of the first connecting part is farther away from the main body than any position of the second connecting part in the first direction. This results in a larger straight-line distance between the first and second connecting parts, further reducing the impact of high temperatures generated at the tabs or second connecting parts during charging and discharging on the first connecting part. This further alleviates the problem of reduced connection strength and toughness at the first connecting part caused by high temperatures at the tabs or second connecting parts, which is beneficial to improving the connection stability between the first wall and the casing, thereby further improving the reliability of the battery cell. Furthermore, the larger straight-line distance between the first and second connecting parts also makes the first connecting part less affected by changes in internal pressure within the battery cell, further alleviating the problem of fatigue failure at the first connecting part caused by changes in internal pressure within the battery cell, improving the reliability of the first connecting part, and thus further improving the reliability of the battery cell. Having a distance between the first and second connecting parts in the first direction greater than or equal to 1 mm also facilitates battery cell assembly.

[0032] In some embodiments of the first aspect of this application, the first portion is connected to the sidewall to form a third connecting portion, and along the first direction, the second connecting portion is further away from the main body portion than the third connecting portion.

[0033] In the above technical solution, by placing the second connecting portion further away from the main body than the third connecting portion along the first direction, the third connecting portion and the second connecting portion do not overlap when viewed from any direction perpendicular to the first direction. Compared to the solution where the third connecting portion and the second connecting portion at least partially overlap when viewed from at least one direction perpendicular to the first direction, in this solution, the distance between the third connecting portion and the second connecting portion is greater, reducing the impact of the high temperature generated at the tab or the second connecting portion on the third connecting portion during charging and discharging. This alleviates the problem of reduced connection strength and toughness at the third connecting portion caused by the high temperature generated at the tab or the second connecting portion, which is beneficial to improving the connection stability between the first part and the sidewall, thereby improving the reliability of the battery cell.

[0034] In some embodiments of the first aspect of this application, the first wall portion is welded to the side wall to form a first connection portion.

[0035] In the above technical solution, the first connection part is formed by welding the first wall part and the side wall, which makes the connection strength between the first wall part and the side wall better, which can reduce the sealing performance and is conducive to the sealing performance between the first wall part and the side wall, thereby improving the reliability of the battery cell.

[0036] In some embodiments of the first aspect of this application, the mounting wall is welded to the sidewall to form a welded portion, the welded portion extending circumferentially along the opening, the first connecting portion being a part of the welded portion, and in a cross-section of the welded portion perpendicular to its extension direction, the dimension of the first connecting portion along the first direction is smaller than the dimension of the first connecting portion along the thickness direction of the sidewall.

[0037] In the above technical solution, by making the dimension of the first connecting part along the first direction smaller than the dimension of the first connecting part along the thickness direction of the sidewall in the cross section perpendicular to the extension direction of the welding part, welding can be performed from the outer surface of the sidewall. In this way, the focal length of the welding equipment can remain unchanged during the welding process, that is, the welding can be completed using the same focal length, making the welding quality of the mounting wall and the sidewall more reliable, thereby improving the reliability of the battery cell.

[0038] In some embodiments of the first aspect of this application, the second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, the first wall portion being further away from the main body portion along the first direction, the outer surface of the first part and the outer surface of the second wall portion being arranged at an obtuse angle; and / or, the inner surface of the first wall portion and the inner surface of the second wall portion being arranged at an obtuse angle.

[0039] In the above technical solution, by arranging the outer surfaces of the first part and the second wall at an obtuse angle, the risk of stress concentration at the transition point between the first part and the second wall can be reduced, extending the service life of the mounting wall and thus extending the service life of the battery cell. Furthermore, if welding is used to connect the mounting wall and the sidewall, the obtuse angle arrangement of the outer surfaces of the first part and the second wall makes the welding process smoother and the weld quality better when welding along the trajectory from the first part to the first wall, thus improving the reliability of the battery cell. Similarly, by arranging the inner surfaces of the first wall and the second wall at an obtuse angle, the risk of stress concentration at the transition point between the second and first walls can be reduced, extending the service life of the mounting wall and thus extending the service life of the battery cell. Furthermore, if welding is used to connect the mounting wall and the sidewall, the obtuse angle arrangement of the outer surfaces of the first and second walls makes the welding process smoother and the weld quality better when welding along the trajectory from the first wall to the second wall, thus improving the reliability of the battery cell.

[0040] In some embodiments of the first aspect of this application, the obtuse angle between the outer surface of the first portion and the outer surface of the second wall portion is A1, 95°≤A1≤170°; and / or, the obtuse angle between the inner surface of the first wall portion and the inner surface of the second wall portion is A2, 95°≤A2≤170°.

[0041] In the above technical solution, by having an obtuse angle between the outer surfaces of the first part and the second wall portion greater than or equal to 95°, the risk of stress concentration at the transition point between the first part and the second wall portion can be reduced, extending the service life of the mounting wall and thus extending the service life of the battery cell. Having an obtuse angle between the outer surfaces of the first part and the second wall portion greater than or equal to 95° allows for a smooth transition from the first part to the second wall portion. When the mounting wall and sidewall are welded together, the welding process is smoother and of better quality as the welding proceeds along the trajectory from the first part to the second wall portion, thus improving the reliability of the battery cell. Having an obtuse angle between the outer surfaces of the first part and the second wall portion less than or equal to 170° avoids the problem of insufficient depth in the recess in the first direction due to an excessively large obtuse angle, which could result in insufficient space to accommodate the tab. This is beneficial for improving the energy density of the battery cell. Therefore, 95°≤A1≤170° can extend the service life of the battery cell, and when the mounting wall and sidewall are welded together, the welding quality is better, improving the reliability of the battery cell and its energy density. By using an obtuse angle greater than or equal to 95° between the inner surfaces of the first and second walls, the risk of stress concentration at the transition point between the first and second walls can be reduced, extending the service life of the mounting wall and thus the service life of the battery cell. Furthermore, the obtuse angle between the inner surfaces of the first and second walls allows for a smooth transition from the first to the second wall. In the case of welded connections between the mounting wall and the sidewall, the welding process is smoother as the welding proceeds along the trajectory from the first to the second wall, resulting in better weld quality and ultimately improving the reliability of the battery cell. By ensuring that the obtuse angle between the inner surfaces of the first and second walls is less than or equal to 170°, the problem of insufficient space in the recess to accommodate the tab is avoided, which is caused by an excessively large obtuse angle between the first and second walls. This is beneficial for improving the energy density of the battery cell. Therefore, 95°≤A2≤170° can extend the service life of the battery cell. In the case of welding connection between the mounting wall and the side wall, the welding quality of the mounting wall and the side wall is better, which improves the reliability of the battery cell and is also beneficial for improving the energy density of the battery cell.

[0042] In some embodiments of the first aspect of this application, 95°≤A1≤120°; and / or, 95°≤A2≤120°.

[0043] In the above technical solution, by having an obtuse angle between the outer surface of the first part and the outer surface of the second wall part less than or equal to 120°, the depth of the recess in the first direction is greater, thereby increasing the space of the recess and allowing it to accommodate the electrode tabs to a greater extent, further improving the energy density of the battery cell. Similarly, by having an obtuse angle between the inner surface of the first wall part and the inner surface of the second wall part less than or equal to 120°, the depth of the recess in the first direction is greater, resulting in a larger space in the recess and allowing it to accommodate the electrode tabs to a greater extent, further improving the energy density of the battery cell.

[0044] In some embodiments of the first aspect of this application, 120°≤A1≤170°; and / or, 120°≤A2≤170°.

[0045] In the above technical solution, since the obtuse angle between the outer surface of the first part and the outer surface of the second wall is greater than or equal to 120°, when welding the mounting wall and the side wall, if welding is performed from the outer surface of the side wall, the welding process is smoother and the welding quality is better when the welding is performed along the trajectory from the first part to the second part, which is beneficial to improving the reliability of the battery cell. Since the obtuse angle between the outer surface of the first part and the outer surface of the second wall is greater than or equal to 120°, the second part protrudes less in the first direction compared to the first part. When welding the mounting wall and the side wall, if welding the mounting wall and the side wall from the outside of the mounting wall, the focal length change of the welding equipment is smaller. Therefore, welding the mounting wall and the side wall from the outside of the side wall or welding the mounting wall and the side wall from the outside of the mounting wall can achieve good welding quality. It can be compatible with both welding the side wall from the outside and welding the mounting wall from the outside, so that the equipment has good compatibility. By ensuring that the obtuse angle between the outer surface of the first part and the outer surface of the second wall is less than or equal to 170°, the problem of insufficient space in the recess to accommodate the tab is avoided, which is caused by an excessively large obtuse angle between the first part and the second wall. This is beneficial to improving the energy density of the battery cell. Therefore, 120°≤A1≤170° ensures better welding quality of the mounting wall and side wall, improves the reliability of the battery cell, is compatible with multiple welding methods, and is beneficial to improving the energy density of the battery cell. With an obtuse angle greater than or equal to 120° between the inner surfaces of the first and second walls, welding from the outer surface of the sidewall to the mounting wall results in a smoother welding process along the trajectory from the first to the second wall, leading to better welding quality and improved reliability of the battery cell. The obtuse angle between the inner surfaces of the first and second walls also results in a smaller protrusion of the second part compared to the first part in the first direction, further reducing the depth of the recess in the first direction during welding. Welding the mounting wall and sidewall from the outer side of the mounting wall minimizes the change in focal length of the welding equipment. Therefore, welding from the outer side of the sidewall or the mounting wall itself yields good welding quality, and the equipment is compatible with both methods, resulting in good equipment compatibility. By ensuring that the obtuse angle between the inner surfaces of the first and second walls is less than or equal to 170°, the problem of insufficient space in the recess to accommodate the tab is avoided, which is caused by an excessively large obtuse angle between the first and second walls. This is beneficial for improving the energy density of the battery cell. Therefore, 120°≤A2≤170° ensures better welding quality of the mounting wall and sidewall, improves the reliability of the battery cell, is compatible with various welding methods, and is beneficial for improving the energy density of the battery cell.

[0046] In some embodiments of the first aspect of this application, the mounting wall includes a plurality of first portions, the battery cell includes a plurality of electrode terminals, the plurality of electrode terminals are respectively disposed in the plurality of first portions, and the electrode terminals are electrically connected to the tabs.

[0047] In the above technical solution, multiple electrode terminals of the battery cell are respectively set in multiple first parts, which facilitates the reasonable arrangement of electrode terminals on the mounting wall, thereby making it convenient for the battery cell to be connected to the external structure through the motor terminal, so that the battery cell can be charged and discharged stably.

[0048] In some embodiments of the first aspect of this application, the mounting wall includes two first portions along a second direction, with the second portion located between the two first portions; the housing includes two first sidewalls disposed opposite each other along a third direction, with the second portion extending to the two first sidewalls along the third direction, both of the two first sidewalls being connected to the second portion, and the second direction, the third direction, and the first direction being perpendicular to each other.

[0049] In the above technical solution, along the second direction, the second part is located between the two first parts. Each of the two first parts can be used to set electrode terminals, which facilitates the electrical connection between the electrode terminals of the battery cell and external devices, reduces the risk of external short circuits in the battery cell, and improves the reliability of the battery cell.

[0050] In some embodiments of the first aspect of this application, the mounting wall includes a plurality of second portions, each of which is provided with a corresponding recess.

[0051] In the above technical solution, the mounting wall includes multiple second parts. On the inner side of the mounting wall, each second part has a corresponding recess. Different polarity tabs can be accommodated in different recesses, reducing the risk of short circuit in the battery cell and improving the reliability of the battery cell.

[0052] In some embodiments of the first aspect of this application, the mounting wall includes two second portions along a second direction, with the first portion located between the two second portions; the housing includes two first sidewalls disposed opposite each other along a third direction and two second sidewalls disposed opposite each other along the second direction, each second portion extending to the two first sidewalls and one second sidewall, both first sidewalls and one second sidewall being connected to one second portion, and both first sidewalls and the other second sidewall being connected to the other second portion.

[0053] In the above technical solution, the mounting wall includes two second parts. Along the second direction, the first part is located between the two second parts. The recesses corresponding to the two second parts can respectively accommodate two tabs with opposite polarities, so that the tabs with opposite polarities are separated by the first part, reducing the risk of short circuit in the battery cell and improving the reliability of the battery cell.

[0054] In some embodiments of the first aspect of this application, the distance between the tab and the edge of the second portion is G, where 0.01mm ≤ G ≤ 5mm.

[0055] In the above technical solution, by using G≥0.01mm, the distance between the tab and the edge of the second part is large enough to facilitate the tab being accommodated in the recessed part, reducing the risk of interference between the tab and other structures inside the casing; by using G≤5mm, the distance between the tab and the edge of the second part is reduced, so that the internal space of the casing can be fully utilized, which is beneficial to improving the volumetric energy density of the battery cell.

[0056] In some embodiments of the first aspect of this application, the second portion is provided with an injection hole.

[0057] In the above technical solution, by setting the injection hole in the second part, the electrolyte can be poured from the tab away from the main body to the electrode assembly during the injection process. This increases the contact area between the electrolyte and the electrode assembly after entering the shell and improves the injection rate, which is beneficial to improving the wetting efficiency of the electrolyte on the electrode assembly.

[0058] In some embodiments of the first aspect of this application, the housing includes a shell, one end of which has an opening along a first direction, and the mounting wall cover is disposed at the opening;

[0059] The battery cell further includes a first insulating member that covers the outer surface of the housing circumferentially along the opening. The first insulating member includes a flange that covers at least a portion of the outer surface of the mounting wall.

[0060] In the above technical solution, by having the first insulating member cover the outer surface of the housing circumferentially along the opening, and the flanged portion of the first insulating member covering at least a portion of the outer surface of the mounting wall, the first insulating member can reduce moisture absorption by the battery cells, reduce the corrosive effect of moisture on the battery cells, and reduce the risk of contact between the battery cells and the external environment, thus extending the service life of the battery cells. It can also reduce the entry of pollutants into the battery cells, such as dust, moisture, and other impurities, which could affect the performance of the battery cells. Furthermore, it reduces the risk of contact between the battery cells and other hard objects, thereby reducing the risk of damage or short circuits caused by external impacts on the battery cells, improving the reliability of the battery cells, and consequently improving the reliability of the battery device. In addition, the fact that the flanged portion of the first insulating member covers at least a portion of the outer surface of the mounting wall reduces the technological difficulty of installing the first insulating member on the outer surface of the housing.

[0061] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion. Along a first direction, the second portion protrudes from the surface of the first portion opposite to the electrode assembly, and a recess is formed on the side of the second portion facing the electrode assembly. The second portion includes a first wall portion and a second wall portion, the second wall portion connecting the first portion and the first wall portion. Along the first direction, the first wall portion is further away from the main body portion than the first portion. The flange includes a first region located in the first portion and a second region located in the first wall portion. The first region covers at least a portion of the outer surface of the first portion, and the second region covers at least a portion of the outer surface of the first wall portion. The width of the second region is smaller than the width of the first region.

[0062] In the above technical solution, the first region covers at least a portion of the outer surface of the first part, the second region covers at least a portion of the outer surface of the first wall, and the width of the second region is smaller than the width of the first region. In the process of assembling the battery cell, the first insulating component of equal width can be used, which is convenient for manufacturing.

[0063] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion. Along a first direction, the second portion protrudes from the surface of the first portion opposite to the electrode assembly, and a recess is formed on the side of the second portion facing the electrode assembly. The second portion includes a first wall portion and a second wall portion, the second wall portion connecting the first portion and the first wall portion. Along the first direction, the first wall portion is further away from the main body portion than the first portion. The flange includes a second region located on the first wall portion. The second region covers a portion of the outer surface of the first wall portion, and the area of ​​the portion of the outer surface of the first wall portion not covered by the second region is larger than the area covered by the second region.

[0064] In the above technical solution, the area of ​​the outer surface of the first wall that is not covered by the second region is larger than the area covered by the second region. That is, a large part of the outer surface of the first wall is not covered by the first insulating member, which facilitates the connection of the battery cell to other structures (such as the housing) in the first wall, thereby improving the stability of the battery cell.

[0065] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion. Along a first direction, the second portion protrudes from the surface of the first portion opposite to the electrode assembly, and a recess is formed on the side of the second portion facing the electrode assembly. The second portion includes a first wall portion and a second wall portion, the second wall portion connecting the first portion and the first wall portion. Along the first direction, the first wall portion is further away from the main body portion than the first portion. The flange includes a first region located in the first portion and a second region located in the first wall portion. The first region covers a portion of the outer surface of the first portion, and the second region covers a portion of the outer surface of the first wall portion. The area of ​​the outer surface of the first wall portion not covered by the second region is greater than the area of ​​the outer surface of the first portion not covered by the flange.

[0066] In the above technical solution, the area of ​​the outer surface of the first wall that is not covered by the second region is greater than the area of ​​the outer surface of the first part that is not covered by the flange. That is, the outer surface of the first wall has a larger area that is not covered by the insulating component, which facilitates the connection of the battery cell to other structures (such as the housing) in the first wall, thereby improving the stability of the battery cell.

[0067] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion, the second portion having a recessed portion on the side facing the electrode assembly, the first portion and the second portion being arranged along a second direction, and along a third direction, the first portion and the second portion having the same size; the battery cell further includes a second insulating member, the second insulating member being connected to the surface of the mounting wall facing the electrode assembly; the second insulating member includes a first insulating portion and a second insulating portion, along the first direction, the second insulating portion protruding from the first insulating portion away from the surface of the electrode assembly, the first insulating portion being disposed corresponding to the first portion, the second insulating portion being disposed corresponding to the second portion, along the third direction, the first insulating portion and the second insulating portion having the same size, and the first direction, the second direction and the third direction.

[0068] In the above technical solution, by having the same size for the first insulating part and the second insulating part along the third direction, it is easy to make the edges of the first insulating part and the second insulating part flush in the third direction, thereby facilitating the cooperation between the second insulating component and other structures of the battery cell, and thus facilitating the assembly of the battery cell.

[0069] In some embodiments of the first aspect of this application, the mounting wall includes a first portion and a second portion, the second portion having a recessed portion on the side facing the electrode assembly; the battery cell further includes a second insulating member, the second insulating member being connected to the surface of the mounting wall facing the electrode assembly; the second insulating member includes a first insulating portion and a second insulating portion, the second insulating portion protruding from the surface of the first insulating portion away from the electrode assembly along the first direction, the first insulating portion being disposed corresponding to the first portion, and the second insulating portion being disposed corresponding to the second portion; both the surface of the first insulating portion facing the electrode assembly and the surface of the second insulating portion facing the electrode assembly are provided with abutting portions, the abutting portions abutting against the main body portion, and along the first direction, the surface of the second insulating portion facing the electrode assembly is further away from the main body portion than the surface of the first insulating portion facing the electrode assembly.

[0070] In the above technical solution, a protruding abutment is provided on the surface of the first insulating portion facing the electrode assembly. The abutment abuts against the main body, which can limit the risk of the electrode assembly moving within the housing or reduce the degree of such movement, thereby improving the reliability of the battery cell. Along the first direction, the surface of the second insulating portion facing the electrode assembly is further away from the main body than the surface of the first insulating portion facing the electrode assembly, reducing the risk of interference between the second insulating portion and the electrode tab.

[0071] Secondly, embodiments of this application also provide a battery device, including the battery cell provided in any embodiment of the first aspect.

[0072] In the above technical solutions, the energy density of the battery cell provided in any embodiment of the first aspect is high, so that the battery device having the battery cell also has a high energy density.

[0073] Thirdly, embodiments of this application also provide an electrical device, including a battery cell provided in any embodiment of the first aspect or a battery device provided in an embodiment of the second aspect.

[0074] In the above technical solutions, the battery cell provided in the first aspect embodiment and the battery device provided in the second aspect embodiment both have high energy densities, which is beneficial to improving the power reliability of the power supply device powered by the battery cell or the battery device. Attached Figure Description

[0075] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0076] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0077] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0078] Figure 3 Axonometric views of a single battery cell provided in some embodiments of this application;

[0079] Figure 4 for Figure 3 Schematic diagram of the middle shell structure;

[0080] Figure 5 for Figure 3 Schematic diagram of the structure of the mounting wall in the middle;

[0081] Figure 6 for Figure 3 A sectional view along line B1-B1;

[0082] Figure 7 for Figure 6 Enlarged view of point C1;

[0083] Figure 8 for Figure 3 A sectional view along line B2-B2;

[0084] Figure 9 for Figure 8 Enlarged view of point C2 in the middle;

[0085] Figure 10 for Figure 8 Enlarged view of point C3 in the middle;

[0086] Figure 11 for Figure 8 Enlarged view of point C5 in the middle;

[0087] Figure 12 Cross-sectional views of the mounting wall provided in some embodiments of this application;

[0088] Figure 13 for Figure 4 Sectional view along line B3-B3;

[0089] Figure 14 Axonometric views of a battery cell provided for other embodiments of this application;

[0090] Figure 15 Axonometric views of a battery cell provided in some further embodiments of this application;

[0091] Figure 16 for Figure 15 Exploded view of the casing and mounting wall of the battery cell;

[0092] Figure 17 for Figure 15 A schematic diagram of the mounting wall and the second insulating component after assembly.

[0093] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing; 12 - Second housing; 20 - Battery cell; 20' - Casing; 21 - Housing; 211 - Opening; 212 - End wall; 213 - Side wall; 2131 - Body; 2132 - Protrusion; 21321 - First end face; 213211 - First outer surface; 213212 - Second outer surface; 2133 - First side wall; 2134 - Second side wall; 22 - Electrode assembly; 221 - Main body; 222 - Tab; 23' - Mounting wall; 23 - End cap; 231 - First part; 2311 - First surface; 2312' - First inner surface; 2312 - Second surface; 232 - ... Two parts; 2321-First wall portion; 2322-Second wall portion; 2323-First arc transition portion; 2324-Second arc transition portion; 2325-Injection hole; 233-Recessed portion; 24-Electrode terminal; 25-Current collector; 251-First section; 252-Second section; 253-Third section; 26-First insulating component; 261-Flanged portion; 2611-First region; 2612-Second region; 27-Second insulating component; 271-First insulating portion; 272-Second insulating portion; 28-Abutting portion; 200-Controller; 300-Motor; Q1-First connecting portion; Q2-Second connecting portion; Q3-Third connecting portion; X-First direction; Y-Second direction; Z-Third direction. Detailed Implementation

[0094] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0095] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0096] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0097] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0098] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0099] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0100] In this application, "multiple" means two or more (including two).

[0101] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0102] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0103] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0104] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0105] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0106] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0107] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0108] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0109] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0110] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0111] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0112] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0113] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0114] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0115] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0116] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0117] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0118] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0119] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0120] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0121] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0122] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0123] As an example, polymer solid electrolytes can be polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0124] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0125] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0126] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0127] In some implementations, the electrode assembly is a stacked structure.

[0128] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0129] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0130] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0131] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0132] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0133] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0134] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0135] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0136] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0137] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0138] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging multiple battery cells and fixing them together to form an independent module.

[0139] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0140] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cell assemblies housed within the housing.

[0141] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0142] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0143] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0144] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0145] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0146] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0147] The battery cell includes a casing and an electrode assembly. The electrode assembly is housed within the casing. The electrode assembly includes a main body and a tab. Along a first direction, the tab is connected to one end of the main body. The casing includes a mounting wall opposite to the tab. Because the tab protrudes from the main body, a large space is not fully utilized between the area of ​​the mounting wall that is not opposite to the tab and the main body in the first direction, resulting in a reduction in the energy density of the battery cell.

[0148] In related technologies, by providing a recess on the first inner surface of the mounting wall facing the electrode assembly, at least a portion of the tab is accommodated in the recess. This provides sufficient space for the tab inside the battery cell and makes full use of the space between the area of ​​the mounting wall not facing the tab and the main body in the first direction, thereby improving the energy density of the battery cell.

[0149] However, in the related technology, the recess is located in the middle region of the first inner surface, that is, the outer periphery of the recess is surrounded by the first inner surface. The space of the recess is small, which means that the portion of the tab that can be accommodated in the recess is small, and it cannot accommodate a large tab, resulting in a low energy density of the battery cell.

[0150] Based on the above considerations, in order to alleviate the problem of low energy density of battery cells, this application provides a battery cell, which includes a housing and an electrode assembly; the housing includes a mounting wall and an electrode terminal is provided on the mounting wall; the electrode assembly is housed in the housing and includes a main body and a tab, and along a first direction, the tab is connected to the end of the main body facing the mounting wall and is electrically connected to the electrode terminal; wherein, the mounting wall has a first inner surface facing the electrode assembly, and a recess is formed on the first inner surface, the recess extending to at least one edge of the first inner surface, and at least a portion of the tab is housed in the recess.

[0151] By providing a recess on the first inner surface of the mounting wall facing the electrode assembly, at least a portion of the tab is accommodated within the recess, which fully utilizes the space inside the casing, thereby reducing the volume of the battery cell and increasing its energy density. The recess extends to at least one edge of the first inner surface, resulting in a larger recess space. This allows for greater accommodation of the tab within the recess or enables the recess to accommodate larger tabs, reducing the space occupied by the tab outside the recess inside the casing and further improving the energy density of the battery cell.

[0152] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0153] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0154] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000.

[0155] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0156] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0157] Please refer to Figure 2 , Figure 2 The following is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and a battery cell 20, wherein the housing 10 is used to house the battery cell 20.

[0158] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing 11 and a second housing 12, which are interlocked. The first housing 11 and the second housing 12 can have various shapes, such as cuboids or cylinders. The first housing 11 can be a hollow structure open on one side, and the second housing 12 can also be a hollow structure open on one side. The open side of the second housing 12 interlocks with the open side of the first housing 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing 11 can be a hollow structure open on one side, and the second housing 12 can be a plate-like structure, with the second housing 12 interlocked with the open side of the first housing 11, thus forming a housing 10 with an accommodating space.

[0159] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0160] In some embodiments, the battery device 100 may further include a busbar (not shown in the figure), through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of multiple battery cells 20. The busbar can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0161] Please refer to Figures 3-5 As shown, Figure 3 Axonometric view of a battery cell 20 provided in some embodiments of this application; Figure 4 for Figure 3 Schematic diagram of the middle shell 21; Figure 5 for Figure 3 A schematic diagram of the structure of the mounting wall 23'. The battery cell 20 includes a casing and an electrode assembly ( Figure 6 , Figure 7 As shown in the figure, the electrode assembly is housed within the housing.

[0162] In some embodiments, the housing includes a housing 21 and an end cap 23; the housing 21 has an opening 211 at at least one end along a first direction X; the electrode assembly 22 includes a body portion 221 and an electrode tab 222, at least a portion of the body portion 221 is housed within the housing 21, and the electrode tab 222 can be connected to the end of the body portion 221 facing the opening 211 along the first direction X.

[0163] The housing 21 has an opening 211, and an end cap 23 is provided on the opening 211 of the housing 21. Here, "provided on" means to cover or close, and can be sealed or unsealed.

[0164] The housing 21 can be a hollow structure with an opening 211 at one end, or it can be a hollow structure with openings 211 at both opposite ends. The main body 221 of the electrode assembly 22 can be entirely located within the housing 21, or it can be partially located within the housing 21 with the other part extending out of the housing 21. The housing 21 can have various shapes, such as cylindrical or cuboid. The housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy. The electrode assembly 22 can be partially or entirely located within the housing 21.

[0165] End cap 23 and housing 21 together define a receiving space for accommodating electrode assembly 22 and other components. End cap 23 can be connected to housing 21 by welding, roll sealing, or other methods to close opening 211 of housing 21. The shape of end cap 23 can be adapted to the shape of housing 21. For example, if housing 21 is a cuboid structure, end cap 23 can be a rectangular plate structure adapted to housing 21; or if housing 21 is a cylindrical structure, end cap 23 can be a circular plate structure adapted to housing 21. The material of end cap 23 can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. The materials of end cap 23 and housing 21 can be the same or different.

[0166] In an embodiment where the housing 21 has an opening 211 at one end, one end cap 23 may be provided. In an embodiment where the housing 21 has openings 211 at both opposite ends, two end caps 23 may be provided, with the two end caps 23 respectively closing the two openings 211 of the housing 21, and the two end caps 23 and the housing 21 together defining the receiving space.

[0167] In some embodiments, the battery cell 20 may further include electrode terminals 24, which are disposed on the housing 21 or end cap 23. The electrode terminals 24 are used for electrical connection with the tabs 222 of the electrode assembly 22 to input or output electrical energy from the battery cell 20. The electrode terminals 24 and tabs 222 can be directly connected, for example, by welding. Alternatively, the electrode terminals 24 and tabs 222 can be indirectly connected, for example, through a current collector 25. Figure 9 , Figure 10 (As shown in the diagram) Indirect connection. The current collector 25 can be a metallic conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0168] As an example, such as Figure 3 , Figure 4 As shown, one end of the housing 21 forms an opening 211, and there is one end cap 23, which closes one opening 211 of the housing 21. The end cap 23 is provided with two electrode terminals 24, which are a positive electrode terminal 24 and a negative electrode terminal 24, respectively. The end of the electrode assembly 22 facing the end cap 23 has a positive electrode tab 222 and a negative electrode tab 222. The positive electrode terminal 24 is electrically connected to the positive electrode tab 222, and the negative electrode terminal 24 is electrically connected to the negative electrode tab 222.

[0169] In this embodiment, the battery cell 20 includes a housing 20' and an electrode assembly 22. The housing 20' includes a mounting wall 23', and the mounting wall 23' is provided with electrode terminals 24. The electrode assembly 22 is housed within the housing 20' and includes a main body 221 and a tab 222. Along a first direction X, the tab 222 is connected to the end of the main body 221 facing the mounting wall 23' and is electrically connected to the electrode terminals 24. The mounting wall 23' has a first inner surface 2312' facing the electrode assembly 22. The first inner surface 2312' has a recess 233, which extends to at least one edge of the first inner surface 2312'. At least a portion of the tab 222 is housed in the recess 233.

[0170] Mounting wall 23' can be any wall portion of the housing, such as the end cap 23 of the housing or a wall portion of the housing 21. For example, as... Figure 3 As shown, mounting wall 23' is end cap 23.

[0171] The electrode assembly 22 with opposite polarities can be located at the same end of the main body 221, or the two electrodes with opposite polarities 222 can be located at opposite ends of the main body 221 along the first direction X. Along the first direction X, the electrode 222 provided at the end of the main body 221 facing the mounting wall 23' is located between the main body 221 and the mounting wall 23'.

[0172] The first inner surface 2312' is the inner surface of the mounting wall 23' facing the electrode assembly 22. The recess 233 is recessed from the first inner surface 2312' in a direction away from the electrode assembly 22. The recess 233 can be formed on the mounting wall 23' by means of grooving, stamping, casting, bending, etc. The mounting wall 23' can be a one-piece molded structure. For example, the mounting wall 23' can be a one-piece molded structure formed by one-piece molding methods such as stamping or casting.

[0173] The edge of the first inner surface 2312' may extend to the edge of the mounting wall 23', that is, in a plane perpendicular to the first direction X, at least a portion of the outer contour of the orthographic projection of the mounting wall 23' overlaps with at least a portion of the outer contour of the first inner surface 2312', wherein the outer contour of the orthographic projection of the mounting wall 23' completely overlaps with the outer contour of the first inner surface 2312', or a portion of the outer contour of the orthographic projection of the mounting wall 23' overlaps with the outer contour of the first inner surface 2312'.

[0174] The edge of the first inner surface 2312' may not extend to the edge of the mounting wall 23', that is, in a plane perpendicular to the first direction X, the outer contour of the orthographic projection of the mounting wall 23' surrounds the outer periphery of the outer contour of the first inner surface 2312'. Embodiments of this application show that the edge of the first inner surface 2312' extends to the edge of the mounting wall 23', and the edge of the first inner surface 2312' is adjacent to one edge of the outer peripheral surface of the mounting wall 23'.

[0175] like Figure 5 As shown, the recess 233 extends to at least one edge of the first inner surface 2312', and a portion of the first inner surface 2312' is located around the periphery of the recess 233. For example, a portion of the first inner surface 2312' is located on one side of the recess 233 along the second direction Y, and another portion of the first inner surface 2312' is located on the other side of the recess 233 along the second direction Y. The recess 233 extends to two opposite edges of the first inner surface 2312' in the third direction Z. Alternatively, the recess 233 extends to two opposite edges of the first inner surface 2312' in the third direction Z and to one edge of the first inner surface 2312' in the second direction Y. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0176] The recess 233 extends to the edge of the first inner surface 2312', and the recess 233 may also extend to the edge of the mounting wall 23'.

[0177] like Figure 6 , Figure 7 As shown, the main body 221 of the electrode assembly 22 includes at least a portion of an insulating member (not shown) along the first direction X, a region of the positive electrode sheet covered by a positive active material along the first direction X, and a region of the negative electrode sheet covered by a negative active material along the first direction X.

[0178] Along the first direction X, the tab 222 can be fully accommodated within the recess 233, or the tab 222 can be partially accommodated within the recess 233. One recess 233 can accommodate one tab 222, or it can accommodate multiple tabs 222.

[0179] By providing a recess 233 on the first inner surface 2312' of the mounting wall 23' facing the electrode assembly, at least a portion of the tab 222 is accommodated within the recess 233. This allows for full utilization of the space inside the housing 20', which is beneficial for reducing the volume of the battery cell 20 and increasing its energy density. The recess 233 extends to at least one edge of the first inner surface 2312', making the space within the recess 233 larger. This allows for a greater degree of accommodation of the tab 222 within the recess 233 or enables the recess 233 to accommodate larger tabs 222, reducing the space occupied by the tab 222 outside the recess 233 inside the housing 20' and further improving the energy density of the battery cell 20.

[0180] like Figure 5 As shown, in some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22; the first portion 231 and the second portion 232 are arranged along the second direction Y and along the third direction Z, the first portion 231 and the second portion 232 have the same size, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0181] The outer peripheral surface of the mounting wall 23' includes two end faces disposed opposite each other in the third direction Z. Since the two end faces of the mounting wall 23' are parallel in the third direction Z, the dimensions of the first part 231 and the second part 232 in the third direction Z are the same. The dimension of the first part 231 in the third direction Z is the distance between the two opposite end faces of the first part 231 in the third direction Z, and the dimension of the second part 232 in the third direction Z is the distance between the two opposite end faces of the second part 232 in the third direction Z.

[0182] By arranging the first part 231 and the second part 232 along the second direction Y, and having the same dimensions along the third direction Z, it is easy to make the edges of the first part 231 and the second part 232 flush in the third direction Z, thereby facilitating the connection of the mounting wall 23' and the other wall parts of the housing 20'.

[0183] like Figure 5 As shown, in some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232, the second portion 232 having a recess 233 on the side facing the electrode assembly 22; the first portion 231 and the second portion 232 are arranged along a second direction Y and along a third direction Z, at least one edge of the first portion 231 and the second portion 232 are flush, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0184] Along the third direction Z, on the same side of the mounting wall 23', the end faces of the first portion 231 and the second portion 232 are flush. Alternatively, on one side of the mounting wall 23' along the third direction Z, the end faces of the first portion 231 and the second portion 232 are flush, while on the other side of the mounting wall 23', they are not flush. Or, on one side of the mounting wall 23' along the third direction Z, the end faces of the first portion 231 and the second portion 232 are flush, while on the other side of the mounting wall 23', the end faces of the first portion 231 and the second portion 232 are also flush, which allows the first portion 231 and the second portion 232 to have the same dimensions along the third direction Z.

[0185] The first part 231 and the second part 232 are flush with at least one edge, which facilitates the connection of the mounting wall 23' and the other wall parts of the housing 20'.

[0186] Please refer to Figure 3 , Figure 5 In some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232. Along a first direction X, the second portion 232 protrudes from the surface of the first portion 231 away from the electrode assembly 22, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22.

[0187] Specifically, along the first direction X, the first portion 231 has a first surface 2311 facing away from the electrode assembly 22 and a second surface 2312 facing the electrode assembly 22. The second portion 232 protrudes from the first surface 2311 in a direction away from the electrode assembly 22, and the recessed portion 233 is recessed from the second surface 2312 in a direction away from the electrode assembly 22. It should be noted that the second surface 2312 can be the first inner surface 2312'.

[0188] The recess 233 and the second part 232 are disposed opposite to each other, and the projection of the second part 232 along the first direction X can be located inside the recess 233. The wall shape of the recess 233 located on the mounting wall 23' can match the shape of the outer surface of the second part 232 in the first direction X.

[0189] By having the second part 232 protrude from the surface of the first part 231 away from the electrode assembly 22, and a recess 233 is formed on the side of the second part 232 facing the electrode assembly 22, the recess can be formed without reducing the thickness of the second part 232, which is beneficial to the uniform wall thickness of the mounting wall 23', making the overall strength of the mounting wall 23' better, thereby improving the mechanical properties of the outer shell 20'.

[0190] like Figure 3 , Figures 8-10As shown, in some embodiments, the battery cell 20 further includes an electrode terminal 24, which is disposed in the first portion 231 and electrically connected to the tab 222.

[0191] In some embodiments, along the first direction X, the electrode terminal 24 may protrude from the surface of the first portion 231 facing away from the electrode assembly 22 (first surface 2311). Alternatively, the surface of the electrode terminal 24 facing away from the electrode assembly 22 may be flush with the surface of the first portion 231 facing away from the electrode assembly 22, or the surface of the electrode terminal 24 facing away from the electrode assembly 22 may be closer to the electrode assembly 22 than the surface of the first portion 231 facing away from the electrode assembly 22. (Figures...) Figure 9 and Figure 10 The diagram shows the electrode terminal 24 protruding from the first portion 231 away from the surface of the electrode assembly 22.

[0192] In an embodiment where the battery cell 20 includes two electrode terminals 24, both electrode terminals 24 may be disposed in the first part 231; or one electrode terminal 24 may be disposed in the first part 231 and the other electrode terminal 24 may be disposed in the second part 232 or the housing 21.

[0193] By placing the electrode terminal 24 on the first part 231, the electrode terminal 24 and the tab 222 overlap in a direction perpendicular to the first direction X. The electrode terminal 24 can make full use of the space formed by the height difference between the first part 231 and the second part 232 in the first direction, which is beneficial to reduce the size of the battery cell 20 and increase the energy density of the battery cell 20.

[0194] like Figures 8-10 As shown, in some embodiments, along the first direction X, the second portion 232 protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22.

[0195] That is, there is a height difference between the second part 232 and the electrode terminal 24 in the first direction X, and the surface of the second part 232 facing away from the electrode assembly 22 is farther away from the electrode assembly 22 than the surface of the electrode terminal 24 facing away from the electrode assembly 22.

[0196] By extending along the first direction X, the second portion 232 protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22. A space is formed between the portion of the second portion 232 that protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22 and the electrode terminal 24. This space can be used to accommodate other structures (such as busbar components) connected to the electrode terminal 24, making it easier to electrically connect the battery cell 20 to other structures, reducing the risk of interference when the battery cell 20 is electrically connected to other structures, and improving the stability of the electrical connection.

[0197] Figure 9 , Figure 10As shown, in some embodiments, along the first direction X, the second portion 232 protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22 by a dimension L, 0.1mm≤L≤5mm.

[0198] Understandably, along the first direction X, the distance between the surface of the second part 232 furthest from the electrode assembly 22 and the surface of the electrode terminal 24 facing away from the electrode assembly 22 is L.

[0199] For example, L can be 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0200] If the second portion 232 protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22 along the first direction X by a size greater than or equal to 0.1 mm, the space formed between the portion of the second portion 232 protruding from the electrode terminal 24 away from the surface of the electrode assembly 22 and the electrode terminal 24 is relatively large. This provides more space for other structures connected to the electrode terminal 24, facilitating electrical connections between the electrode terminal 24 and other structures. This makes electrical connections between the battery cell 20 and other structures more convenient, reduces the risk of interference during electrical connections, improves the stability of electrical connections, and makes the overall structure more compact after the battery cell 20 is electrically connected to other structures. If the second portion 232 protrudes from the electrode terminal 24 away from the surface of the electrode assembly 22 along the first direction X by a size less than or equal to 5 mm, controlling the maximum size of the second portion 232 protruding from the electrode terminal 24 away from the surface of the electrode assembly 22 along the first direction X helps to reduce the size of the battery cell 20 in the first direction X, thereby reducing the volume of the battery cell 20 and increasing its energy density. Therefore, 0.1mm≤L≤5mm not only facilitates the electrical connection of the battery cell 20 with other structures, but also helps the battery cell 20 to have a higher energy density.

[0201] like Figure 9 , Figure 10 As shown, in some embodiments, when viewed along at least one direction perpendicular to the first direction X, at least a portion of the tab 222 overlaps with at least a portion of the electrode terminal 24.

[0202] Based on the different relative positions of the electrode terminal 24 and the tab 222, it was observed that at least a portion of the tab 222 overlaps with at least a portion of the electrode terminal 24 in different directions.

[0203] For example, the portion of the tab 222 housed in the recess 233 is arranged with the electrode terminal 24 along the second direction Y. When viewed along the second direction Y, the portion of the tab 222 housed in the recess 233 overlaps with at least a portion of the electrode terminal 24. The second direction Y is a direction perpendicular to the first direction X.

[0204] When viewed along at least one direction perpendicular to the first direction X, at least a portion of the tab 222 overlaps with at least a portion of the electrode terminal 24, allowing the electrode terminal 24 to make full use of the space formed by the height difference between the first portion 231 and the second portion 232 in the first direction X, which is beneficial to reducing the size of the battery cell 20 and increasing the energy density of the battery cell 20.

[0205] Please continue to refer to Figures 3-5 In some embodiments, the outer casing 20' includes an end wall 212 and a side wall 213. Along the first direction X, the end wall 212 and the mounting wall 23' are disposed opposite to each other. The side wall 213 includes a body portion 2131 and a protrusion 2132. The body portion 2131 surrounds the outer periphery of the end wall 212. Along the first direction X, one end of the body portion 2131 is connected to the end wall 212, and the other end of the body portion 2131 is connected to the protrusion 2132. The protrusion 2132 protrudes from the end of the body portion 2131 away from the end wall 212. A portion of the body portion 2131 is connected to a first portion 231, and the protrusion 2132 is connected to a second portion 232.

[0206] A portion of the main body 2131 can be directly connected to the first portion 231, meaning that the portion of the main body 2131 and the first portion 231 do not need to be connected through other parts of the mounting wall 23'. The portion of the main body 2131 and the first portion 231 can be connected by welding, sealant, etc.

[0207] The portion of the protrusion 2132 and the second portion 232 can be directly connected, meaning that the portion of the protrusion 2132 and the second portion 232 do not need to be connected through other parts of the mounting wall 23'. The portion of the protrusion 2132 and the second portion 232 can be connected by welding, sealant, etc.

[0208] A protrusion 2132 protrudes from a portion of the end of the main body 2131 away from the end wall 212. The protrusion 2132 and the main body 2131 can be integrally formed or can be separately provided and connected.

[0209] The protrusion 2132 is provided at the edge of the second part 232 that is not connected to the first part 231. The area of ​​the body part 2131 that is away from the end wall 212 and does not have the protrusion 2132 is connected to the first part 231.

[0210] By providing a protrusion 2132 at one end of the body portion 2131 of the side wall 213 away from the end wall 212, a portion of the body portion 2131 is directly connected to the first portion 231, and the protrusion 2132 is directly connected to the second portion 232. The height position of the area where the side wall 213 is connected to the first portion 231 in the first direction X corresponds to the first portion 231, and the height position of the area where the side wall 213 is connected to the second portion 232 in the first direction X corresponds to the second portion 232, which facilitates the connection between the first portion 231 and the second portion 232 and the side wall 213, thereby facilitating the connection between the mounting wall 23' and the side wall 213.

[0211] like Figure 3 , Figures 5-7 As shown, in some embodiments, the outer casing 20' further includes an end wall 212 and a side wall 213. The side wall 213 surrounds the outer periphery of the end wall 212. One end of the side wall 213 is connected to the end wall 212, and the other end of the side wall 213 forms an opening 211. The mounting wall 23' covers the opening 211. The second part 232 includes a first wall portion 2321 and a second wall portion 2322. The second wall portion 2322 connects the first part 231 and the first wall portion 2321. Along the first direction X, the first wall portion 2321 is further away from the main body 221 than the first part 231. The first wall portion 2321 is connected to the side wall 213 to form a first connecting portion Q1. Along the first direction X, the first connecting portion Q1 is further away from the main body 221 than the tab 222.

[0212] If the mounting wall 23' covers the opening, then the mounting wall 23' is the end cap 23. The side wall and the end wall together form the shell 21 of the outer shell 20'.

[0213] The second part 232 is directly connected to the side wall 213, meaning that the second part 232 and the side wall 213 do not need to be connected through other parts of the mounting wall 23'. The second part 232 and the side wall 213 can be connected by welding, adhesive bonding, etc. The edge of the second part 232 that is not connected to the first part 231 is part of the edge of the mounting wall 23', so that the area of ​​the second part 232 that is not connected to the first part 231 can be directly connected to the side wall 213.

[0214] The second part 232 is directly connected to the side wall 213. In this case, part of the edge of the second part 232 is part of the edge of the mounting wall 23'. The second part 232 extends to the edge of the mounting wall 23'. Compared with the scheme in which the second part 232 is connected to the side wall 213 through the first part 231, that is, compared with the scheme in which the second part 232 does not extend to the edge of the mounting wall 23', in this scheme, the area of ​​the second part 232 is larger. This is beneficial to forming a larger volume recess 233 in the area inside the mounting wall 23' and corresponding to the second part 232. This allows the tab 222 to be accommodated to a greater extent in the recess 233 or the recess 233 to accommodate a larger size tab 222. This can reduce the gap between the mounting wall 23' and the electrode assembly 22, make full use of the space inside the battery cell 20, and thus improve the energy density.

[0215] Therefore, the first wall portion 2321 is directly connected to the side wall 213.

[0216] In the first direction X, the first wall portion 2321 is farther away from the main body portion 221 than the first part 231. Understandably, along the first direction X, the inner surface of the first wall portion 2321 is farther away from the main body portion 221 than the inner surface of the first part 231, and the outer surface of the first wall portion 2321 is farther away from the main body portion 221 than the outer surface of the first part 231. Specifically, the inner surface of the first wall portion 2321 can be closer to the main body portion 221 than the outer surface of the first part 231, and the inner surface of the first wall portion 2321 can also be farther away from the main body portion 221 than the outer surface of the first part 231.

[0217] Since, in the first direction X, the inner surface of the first wall portion 2321 is farther from the main body portion 221 than the inner surface of the first part 231, the distance between the inner surface of the first part 231 and the inner surface of the first wall portion 2321 is the depth of the recess 233. The tab 222 can be completely accommodated within the recess 233, or the tab 222 can be partially accommodated within the recess 233.

[0218] In this embodiment, the edge of the first wall portion 2321 that is not connected to the second wall portion 2322 forms the edge of the mounting wall 23'. The edge region of the first wall portion 2321 that is not connected to the second wall portion 2322 is connected to the side wall 213 to form the first connecting portion Q1.

[0219] Along the first direction X, the first connecting portion Q1 is further away from the main body portion 221 than the tab 222. This can be because the distance between the end of the first connecting portion Q1 closest to the main body portion 221 and the main body portion 221 is not less than the distance between the end of the tab 222 furthest from the main body portion 221 and the main body portion 221. It can be understood that, along the first direction X, the distance between the end of the first connecting portion Q1 closest to the main body portion 221 and the main body portion 221 can be equal to the distance between the end of the tab 222 furthest from the main body portion 221 and the main body portion 221, or the distance between the end of the first connecting portion Q1 closest to the main body portion 221 and the main body portion 221 can be greater than the distance between the end of the tab 222 furthest from the main body portion 221 and the main body portion 221.

[0220] The first connecting portion Q1, formed by the connection of the side wall 213 and the first wall portion 2321, is farther away from the main body portion 221 than the tab 222. Therefore, when viewed along any direction perpendicular to the first direction X, the first connecting portion Q1 and the tab 222 do not overlap. Compared to the scheme where the first connecting portion Q1 and the tab 222 at least partially overlap when viewed along at least one direction perpendicular to the first direction X, in this scheme, the distance between the first connecting portion Q1 and the tab 222 is greater, which reduces the impact of the high temperature generated at the tab 222 on the first connecting portion Q1 during charging and discharging. This alleviates the problem of reduced connection strength and toughness at the first connecting portion Q1 caused by the high temperature generated at the tab 222, which is beneficial to improving the connection stability of the first wall portion 2321 and the side wall 213, thereby improving the reliability of the battery cell 20. Since the first connecting part Q1 is further away from the main body 221 than the tab 222 along the first direction X, the distance between the first connecting part Q1 and the main body 221 is increased. The first connecting part Q1 is less affected by the internal pressure change of the battery cell 20, thereby alleviating the problem of fatigue failure at the first connecting part Q1 caused by the internal pressure change of the battery cell 20, improving the reliability of the first connecting part Q1, and further improving the reliability of the battery cell 20.

[0221] like Figures 6-10 As shown, in some embodiments, the battery cell 20 further includes an electrode terminal 24 disposed in the first portion 231. The battery cell 20 also includes a current collector 25 connected to the tab 222 and the electrode terminal 24. At least a portion of the current collector 25 is located in the recess 233 and is connected to the tab 222 to form a second connection portion Q2. Along the first direction X, the first connection portion Q1 is further away from the main body portion 221 than the second connection portion Q2.

[0222] Electrode terminal 24 and tab 222 are electrically connected via current collector 25, meaning they are indirectly connected. Electrode terminal 24 and current collector 25 can be connected by welding, conductive adhesive, or other methods. Tab 222 and current collector 25 can also be connected by welding, conductive adhesive, or other methods. Figures 8-10 As shown, there are two electrode terminals 24, which are electrically connected to the positive electrode tab 222 and the negative electrode tab 222 respectively. The battery cell 20 may include two current collectors 25. One electrode terminal 24 and the positive electrode tab 222 are electrically connected through one current collector 25, and the other electrode terminal 24 and the negative electrode tab 222 are electrically connected through another current collector 25.

[0223] Generally, each tab 222 includes multiple tab portions 222. After the electrode assembly 22 is manufactured, the multiple tab portions 222 are stacked to form a common stacked area. In the common stacked area, the orthographic projections of any two tab portions 222 overlap. The current collector 25 is connected to the common stacked area of ​​the tabs 222. The second connection portion Q2 includes a portion of the current collector 25 and at least a portion of the common stacked area.

[0224] In some embodiments, along the first direction X, the size of the second connection Q2 is greater than or equal to the sum of the size of the current collection member 25 and the size of the common stacking area.

[0225] Along the first direction X, the first connecting portion Q1 is further away from the main body 221 than the second connecting portion Q2. Specifically, along the first direction X, the distance between the end of the first connecting portion Q1 closest to the main body 221 and the main body 221 is not less than the distance between the end of the second connecting portion Q2 furthest from the main body 221 and the main body 221. It can be understood that, along the first direction X, the distance between the end of the first connecting portion Q1 closest to the main body 221 and the main body 221 can be equal to the distance between the end of the second connecting portion Q2 furthest from the main body 221 and the main body 221, or the distance between the end of the first connecting portion Q1 closest to the main body 221 and the main body 221 can be greater than the distance between the end of the second connecting portion Q2 furthest from the main body 221 and the main body 221.

[0226] Specifically, such as Figure 9 , Figure 10As shown, the current collector 25 includes a first segment 251, a second segment 252, and a third segment 253. The second segment 252 connects the first segment 251 and the third segment 253. The first segment 251 is located within the recess 233 and is connected to the tab 222 to form a second connection portion Q2. The second segment 252 and the third segment 253 are located outside the recess 233. The third segment 253 can be stacked and connected to the electrode terminal 24 along the first direction X. Along the first direction X, the first segment 251 is farther away from the main body 221 than the third segment 253. Understandably, along the first direction X, the surface of the first segment 251 facing the main body 221 is farther away from the main body 221 than the surface of the third segment 253 facing the electrode assembly 22, and the surface of the first segment 251 facing away from the main body 221 is farther away from the main body 221 than the surface of the third segment 253 facing away from the main body 221. The inner surface of the first segment 251 can be closer to the main body 221 than the outer surface of the third segment 253, and the inner surface of the first segment 251 can be farther away from the main body 221 than the outer surface of the third segment 253.

[0227] At least a portion of the tab 222 may be stacked with the first segment 251 in the first direction X. For example, the first segment 251 may be located on the side of the tab 222 away from the main body 221 along the first direction X, or a portion of the tab 222 may be located on the side of the first segment 251 away from the main body 221, and another portion of the tab 222 may be located on the side of the first segment 251 facing the main body 221.

[0228] The tab 222 and the electrode terminal 24 are connected by the current collector 25, which facilitates the electrical connection between the tab 222 and the electrode terminal 24 located in the recess 233.

[0229] A portion of the current collector 25 is located within the recess 233 and connected to the tab 222 to form a second connection Q2. Since the first connection Q1 is further away from the main body 221 than the second connection Q2 along the first direction X, when viewed from any direction perpendicular to the first direction, neither the first connection Q1 nor the second connection Q2 overlaps, nor do any position of the first connection Q1 and the tab 222 overlap. Compared to schemes where the first connection Q1 and the second connection Q2 at least partially overlap when viewed from at least one direction perpendicular to the first direction X, and schemes where the first connection Q1 and the tab 222 at least partially overlap, in this scheme, the distance between the first connection Q1 and the second connection Q2 is greater. This reduces the impact of the high temperature generated at the tab 222 or the second connection Q2 on the first connection Q1 during charging and discharging, thereby alleviating the problem of reduced connection strength and toughness at the first connection Q1 due to the high temperature generated at the tab 222 or the second connection Q2. This is beneficial for improving the connection stability of the first wall 2321 and the casing 21, thereby improving the reliability of the battery cell 20. Since the first connecting portion Q1 is further away from the main body 221 than the second connecting portion Q2 along the first direction X, the distance between the first connecting portion Q1 and the main body 221 of the electrode assembly 22 is increased. The first connecting portion Q1 is less affected by the internal pressure change of the battery cell 20, thereby alleviating the problem of fatigue failure at the first connecting portion Q1 caused by the internal pressure change of the battery cell 20, improving the reliability of the first connecting portion Q1, and further improving the reliability of the battery cell 20.

[0230] Please continue to refer to Figure 9 , Figure 10 In some embodiments, the current collector 25 includes a first segment 251 arranged with the tab 222 along the first direction X. The first segment 251 is connected to the tab 222 to form a second connection portion Q2. Along the first direction X, the first segment 251 is located on the side of the tab 222 away from the main body 221, and the first connection portion Q1 is further away from the main body 221 than the first segment 251.

[0231] The second connecting portion Q2 includes at least a portion of the first segment 251 and at least a portion of the common stacked area. Along the first direction X, the size of the second connecting portion Q2 is greater than or equal to the sum of the size of the first segment 251 and the size of the common stacked area.

[0232] The first segment 251 is located on the side of the tab 222 away from the main body 221, which facilitates the installation of the current collector 25 and the connection between the current collector 25 and the tab 222 to form the first connection portion Q1. During charging and discharging, the first segment 251 connecting the current collector 25 and the tab 222 also has a high temperature. With the first segment 251 of the current collector 25 located on the side of the tab 222 away from the main body 221, the first connection portion Q1 is farther away from the main body 221 than the first segment 251. The first connection portion Q1 is less affected by the high temperature of the tab 222 and the current collector 25, thereby alleviating the problem of reduced connection strength and toughness at the first connection portion Q1 due to the high temperature at the connection between the tab 222 and the current collector 25. This is beneficial to improving the connection stability between the first wall portion 2321 and the casing 21, thereby improving the reliability of the battery cell 20. Since the first connecting part Q1 is further away from the main body 221 than the first segment 251 along the first direction X, the first connecting part Q1 is less affected by the internal pressure change of the battery cell 20, thereby alleviating the problem of fatigue failure at the first connecting part Q1 caused by the internal pressure change of the battery cell 20, improving the reliability of the first connecting part Q1, and further improving the reliability of the battery cell 20.

[0233] The portion of tab 222 is located on the side of the first segment 251 away from the main body 221, and the other portion of tab 222 is located on the side of the first segment 251 facing the main body 221. The common lamination area may be located on the side of the first segment 251 away from the main body 221, and at least a portion of the area outside the common lamination area of ​​tab 222 is located on the side of the first segment 251 facing the main body 221.

[0234] Along the first direction X, the distance between the end of the second connecting portion Q2 furthest from the main body portion 221 and the main body portion 221 can be equal to the distance between the surface of the common lamination region away from the first segment 251 and the main body portion 221. Of course, the distance between the end of the second connecting portion Q2 furthest from the main body portion 221 and the main body portion 221 can also be greater than the distance between the surface of the common lamination region away from the tab 222 and the main body portion 221.

[0235] like Figure 7 As shown, along the first direction X, the distance between the first connecting portion Q1 and the second connecting portion Q2 is H, and in some embodiments, H=0. It can be understood that along the first direction X, the distance between the end of the first connecting portion Q1 closest to the main body portion 221 and the main body portion 221 is the same as the distance between the end of the second connecting portion Q2 furthest from the main body portion 221 and the main body portion 221.

[0236] Please refer to Figure 7 In some embodiments, the distance between the first connecting portion Q1 and the second connecting portion Q2 along the first direction X is H, where H > 0.

[0237] Understandably, along the first direction X, the distance between the end of the first connecting portion Q1 closest to the main body portion 221 and the main body portion 221 is greater than the distance between the end of the second connecting portion Q2 furthest from the main body portion 221 and the main body portion 221.

[0238] Since the distance between the first connecting portion Q1 and the second connecting portion Q2 in the first direction X is greater than 0, any position of the first connecting portion Q1 is farther away from the main body 221 than any position of the second connecting portion Q2 in the first direction X. This results in a larger straight-line distance between the first connecting portion Q1 and the second connecting portion Q2, reducing the impact of the high temperature generated at the tab 222 or the second connecting portion Q2 during charging and discharging on the first connecting portion Q1. This alleviates the problem of reduced connection strength and toughness at the first connecting portion Q1 caused by the high temperature generated at the tab 222 or the second connecting portion Q2, which is beneficial to improving the connection stability of the first wall portion 2321 and the shell 21, thereby improving the reliability of the battery cell 20. In addition, the larger straight-line distance between the first connecting portion Q1 and the second connecting portion Q2 also makes the first connecting portion Q1 less affected by the internal pressure changes of the battery cell 20, thereby alleviating the problem of fatigue failure at the first connecting portion Q1 caused by the internal pressure changes of the battery cell 20, improving the reliability of the first connecting portion Q1, and further improving the reliability of the battery cell 20.

[0239] In some embodiments, H ≥ 1 mm.

[0240] For example, H can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0241] With the distance between the first connecting portion Q1 and the second connecting portion Q2 in the first direction X being greater than or equal to 1 mm, any position of the first connecting portion Q1 is farther from the main body 221 than any position of the second connecting portion Q2 in the first direction X. This results in a larger straight-line distance between the first connecting portion Q1 and the second connecting portion Q2, further reducing the impact of the high temperature generated at the tab 222 or the second connecting portion Q2 on the first connecting portion Q1 during charging and discharging. This further alleviates the problem of reduced connection strength and toughness at the first connecting portion Q1 caused by the high temperature generated at the tab 222 or the second connecting portion Q2, which is beneficial to improving the connection stability between the first wall portion 2321 and the shell 21, thereby further improving the reliability of the battery cell 20. In addition, the larger straight-line distance between the first connecting portion Q1 and the second connecting portion Q2 also makes the first connecting portion Q1 less affected by the internal pressure changes of the battery cell 20, thereby further alleviating the problem of fatigue failure at the first connecting portion Q1 caused by the internal pressure changes of the battery cell 20, improving the reliability of the first connecting portion Q1, and thus further improving the reliability of the battery cell 20. The fact that the distance between the first connecting part Q1 and the second connecting part Q2 in the first direction is greater than or equal to 1 mm also facilitates the assembly of the battery cell 20.

[0242] Combined with reference Figures 9-11 In some embodiments, the first portion 231 is connected to the sidewall 213 to form a third connecting portion Q3, and along the first direction X, the second connecting portion Q2 is further away from the main body portion 221 than the third connecting portion Q3.

[0243] Along the first direction X, the end of the second connecting part Q2 closest to the main body 221 may be flush with the end of the third connecting part Q3 furthest from the main body 221, or the end of the second connecting part Q2 closest to the main body 221 may be further away from the main body 221 than the end of the third connecting part Q3 furthest from the main body 221.

[0244] By making the second connecting portion Q2 further away from the main body 221 along the first direction X than the third connecting portion Q3, when viewed along any direction perpendicular to the first direction X, the third connecting portion Q3 and the second connecting portion Q2 do not overlap. Compared to a scheme where the third connecting portion Q3 and the second connecting portion Q2 at least partially overlap when viewed along at least one direction perpendicular to the first direction X, in this scheme, the distance between the third connecting portion Q3 and the second connecting portion Q2 is greater, reducing the impact of the high temperature generated at the tab 222 or the second connecting portion Q2 on the third connecting portion Q3 during charging and discharging. This alleviates the problem of reduced connection strength and toughness at the third connecting portion Q3 due to the high temperature generated at the tab 222 or the second connecting portion Q2, which is beneficial to improving the connection stability of the first part 231 and the side wall 213, thereby improving the reliability of the battery cell 20.

[0245] like Figure 7As shown, the first wall portion 2321 is welded to the side wall 213 to form the first connecting portion Q1.

[0246] If the first wall portion 2321 and the side wall 213 are welded together, then the first connecting portion Q1 can be a welded portion.

[0247] The first wall 2321 and the side wall 213 can be welded together by means of laser welding, ultrasonic welding or other methods.

[0248] The first connecting part Q1 is formed by welding the first wall part 2321 to the side wall 213, which makes the first wall part 2321 and the side wall 213 have better connection strength, which can reduce the sealing performance and is conducive to the better sealing performance between the first wall part 2321 and the side wall 213, thereby improving the reliability of the battery cell 20.

[0249] like Figure 7 As shown, in some embodiments, the mounting wall 23' is welded to the side wall 213 to form a welded portion, which extends circumferentially along the opening 211. The first connecting portion Q1 is part of the welded portion. In the cross-section of the welded portion perpendicular to its extension direction, the dimension of the first connecting portion Q1 along the first direction X is smaller than the dimension of the first connecting portion Q1 along the thickness direction of the side wall 213.

[0250] The welded portion extends circumferentially along the opening 211. Understandably, along the circumferential direction of the opening 211, any position of the mounting wall 23' is welded to the side wall 213.

[0251] Wherein, the edge of the first part 231 that is not connected to the second part 232 is welded to the side wall 213, and the edge of the second part 232 that is not connected to the first part 231 is welded to the side wall 213.

[0252] Figure 7 The image shows a cross-section of the welded portion at the first connecting portion Q1. The dimension of the first connecting portion Q1 along the first direction X is K, and the dimension of the first connecting portion Q1 along the thickness direction of the sidewall 213 is W, where K < W.

[0253] By making the dimension of the first connecting part Q1 along the first direction X smaller than the dimension of the first connecting part Q1 along the thickness direction of the side wall 213 in the cross section perpendicular to the extension direction of the welding part, welding can be performed from the outer surface of the side wall 213. In this way, the focal length of the welding equipment can remain unchanged during the welding process, that is, the welding can be completed using the same focal length, making the welding quality of the mounting wall 23' and the side wall 213 more reliable, thereby improving the reliability of the battery cell 20.

[0254] like Figure 12As shown, in some embodiments, the second part 232 includes a first wall portion 2321 and a second wall portion 2322, the second wall portion 2322 connecting the first part 231 and the first wall portion 2321. Along the first direction X, the first wall portion 2321 is further away from the main body portion 221 than the first part 231. The outer surfaces of the first part 231 and the second wall portion 2322 are arranged at an obtuse angle; and / or, the inner surfaces of the first wall portion 2321 and the second wall portion 2322 are arranged at an obtuse angle.

[0255] Along the first direction X, the outer surface of the first part 231 is the first surface 2311, the inner surface of the first part 231 is the second surface 2312, the inner surface of the first wall part 2321 is the surface of the first wall part 2321 facing the electrode assembly 22, and the outer surface of the first wall part 2321 is the surface of the first wall part 2321 away from the electrode assembly 22.

[0256] The outer surface and inner surface of the first portion 231 are parallel, and the outer surface and inner surface of the second wall portion 2322 are parallel, meaning the inner surfaces of the first portion 231 and the second wall portion 2322 are arranged at an obtuse angle. Alternatively, the outer surface and inner surface of the first wall portion 2321 are parallel, and the outer surface and inner surface of the second wall portion 2322 are parallel, meaning the inner surfaces of the first wall portion 2321 and the second wall portion 2322 are arranged at an obtuse angle.

[0257] In the embodiment where the outer surface of the first portion 231 and the outer surface of the second wall portion 2322 are arranged at an obtuse angle, and the outer surface of the second wall portion 2322 and the outer surface of the first wall portion 2321 are arranged at an obtuse angle, the obtuse angle between the outer surface of the first portion 231 and the outer surface of the second wall portion 2322 can be the same as or different from the obtuse angle between the outer surface of the second wall portion 2322 and the outer surface of the first wall portion 2321.

[0258] By arranging the outer surfaces of the first portion 231 and the second wall portion 2322 at an obtuse angle, the risk of stress concentration at the transition point between the first portion 231 and the second wall portion 2322 can be reduced, extending the service life of the mounting wall 23' and thus extending the service life of the battery cell 20. Furthermore, if the mounting wall 23' and the shell sidewall 213 are connected by welding, the obtuse angle arrangement of the outer surfaces of the first portion 231 and the second wall portion 2322 makes the welding process smoother and the welding quality better when the welding is performed along the trajectory from the first portion 231 to the first wall portion 2321, thus improving the reliability of the battery cell 20. Similarly, by arranging the inner surfaces of the first wall portion 2321 and the second wall portion 2322 at an obtuse angle, the risk of stress concentration at the transition point between the second wall portion 2322 and the first wall portion 2321 can be reduced, extending the service life of the mounting wall 23' and thus extending the service life of the battery cell 20. Furthermore, if the mounting wall 23' and the side wall 213 are connected by welding, the outer surfaces of the first wall portion 2321 and the second wall portion 2322 are arranged at an obtuse angle. When welding is carried out along the trajectory from the first wall portion 2321 to the second wall portion 2322, the welding process is smoother, resulting in better welding quality, which is beneficial to improving the reliability of the battery cell 20.

[0259] In some embodiments, the obtuse angle between the outer surface of the first portion 231 and the outer surface of the second wall portion 2322 is A1, 95°≤A1≤170°; and / or, the obtuse angle between the inner surface of the first wall portion 2321 and the inner surface of the second wall portion 2322 is A2, 95°≤A2≤170°.

[0260] For example, A1 can be 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, etc.

[0261] And / or, A2 can be 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, etc.

[0262] By using an obtuse angle greater than or equal to 95° between the outer surfaces of the first portion 231 and the second wall portion 2322, the risk of stress concentration at the transition point between the first portion 231 and the second wall portion 2322 can be reduced, extending the service life of the mounting wall 23' and thus extending the service life of the battery cell 20. The obtuse angle between the outer surfaces of the first portion 231 and the second wall portion 2322 is also greater than or equal to 95°, allowing for a smooth transition from the first portion 231 to the second wall portion 2322. When the mounting wall 23' and the side wall 213 are welded together, the welding process is smoother and of better quality as the welding proceeds along the trajectory from the first portion 231 to the second wall portion 2322, thereby improving the reliability of the battery cell 20. By ensuring that the obtuse angle between the outer surface of the first part 231 and the outer surface of the second wall part 2322 is less than or equal to 170°, the problem of insufficient space in the recess 233 to accommodate the tab 222 due to the excessively large obtuse angle between the first part 231 and the second wall part 2322 is avoided. This is beneficial to improving the energy density of the battery cell 20. Therefore, 95°≤A1≤170° can extend the service life of the battery cell 20. In the case of welding connection between the mounting wall 23' and the side wall 213, the welding quality of the mounting wall 23' and the side wall 213 is better, which improves the reliability of the battery cell 20 and is beneficial to improving the energy density of the battery cell 20.

[0263] By ensuring that the obtuse angle between the inner surfaces of the first wall portion 2321 and the second wall portion 2322 is greater than or equal to 95°, the risk of stress concentration at the transition point between the mounting wall 23' and the second wall portion 2321 can be reduced, extending the service life of the mounting wall 23' and thus extending the service life of the battery cell 20. Furthermore, the obtuse angle between the inner surfaces of the first wall portion 2321 and the second wall portion 2322 is greater than or equal to 95°, allowing for a smooth transition from the first wall portion 2321 to the second wall portion 2322. When the mounting wall 23' and the side wall 213 are welded together, the welding process is smoother and of better quality as the welding proceeds along the trajectory from the first wall portion 2321 to the second wall portion 2322, thereby improving the reliability of the battery cell 20. By ensuring that the obtuse angle between the inner surface of the first wall portion 2321 and the inner surface of the second wall portion 2322 is less than or equal to 170°, the problem of insufficient space in the recess 233 to accommodate the tab 222 due to the excessively large obtuse angle between the first wall portion 2321 and the second wall portion 2322 is avoided. This is beneficial to improving the energy density of the battery cell 20. Therefore, 95°≤A2≤170° can extend the service life of the battery cell 20. In the case of welding connection between the mounting wall 23' and the side wall 213, the welding quality of the mounting wall 23' and the side wall 213 is better, improving the reliability of the battery cell 20 and also contributing to the improvement of the energy density of the battery cell 20.

[0264] Furthermore, 95°≤A1≤120°; and / or, 95°≤A2≤120°.

[0265] For example, A1 can be 95°, 96°, 97°, 98°, 99°, 101°, 102°, 103°, 104°, 106°, 107°, 108°, 109°, 120°, etc.

[0266] And / or, A2 can be 95°, 96°, 97°, 98°, 99°, 101°, 102°, 103°, 104°, 106°, 107°, 108°, 109°, 120°, etc.

[0267] The obtuse angle between the outer surface of the first portion 231 and the outer surface of the second wall portion 2322 is less than or equal to 120°, resulting in a greater depth of the recess 233 in the first direction X. This increases the space within the recess 233, allowing it to accommodate the tab 222 to a greater extent, further improving the energy density of the battery cell 20. Similarly, the obtuse angle between the inner surface of the first wall portion 2321 and the inner surface of the second wall portion 2322 is less than or equal to 120°, resulting in a greater depth of the recess 233 in the first direction X. This also increases the space within the recess 233, allowing it to accommodate the tab 222 to a greater extent, further improving the energy density of the battery cell 20.

[0268] In other embodiments, 120°≤A1≤170°; and / or, 120°≤A2≤170°.

[0269] For example, A1 can be 120°, 122°, 124°, 126°, 128°, 132°, 134°, 136°, 138°, 142°, 144°, 146°, 148°, 152°, 156°, 158°, 162°, 164°, 166°, 168°, 170°, etc.

[0270] And / or, A2 can be 120°, 122°, 124°, 126°, 128°, 132°, 134°, 136°, 138°, 142°, 144°, 146°, 148°, 152°, 156°, 158°, 162°, 164°, 166°, 168°, 170°, etc.

[0271] When the obtuse angle between the outer surface of the first part 231 and the outer surface of the second wall part 2322 is greater than or equal to 120°, and the mounting wall 23' and side wall 213 are welded, if welding is performed from the outer surface of the side wall 213 of the housing 21, the welding process is smoother and the welding quality is better when the welding is performed along the trajectory from the first part 231 to the second part 232. This is beneficial to improving the reliability of the battery cell 20. The obtuse angle between the outer surface of the first part 231 and the outer surface of the second wall part 2322 is greater than or equal to 120°, making the second part 23'... Compared to the first part 231, the height of the protrusion in the first direction X is smaller. When welding the mounting wall 23' and the side wall 213, if the mounting wall 23' and the side wall 213 are welded from the outside of the mounting wall 23', the focal length of the welding equipment changes less. Therefore, good welding quality can be obtained by welding the mounting wall 23' and the side wall 213 from the outside of the side wall 213, or welding the mounting wall 23' and the side wall 213 from the outside of the mounting wall 23'. It can be compatible with both welding the side wall 213 from the outside and welding the mounting wall 23' from the outside, so the equipment has good compatibility. By ensuring that the obtuse angle between the outer surface of the first part 231 and the outer surface of the second wall part 2322 is less than or equal to 170°, the problem of insufficient space in the recess 233 to accommodate the tab 222 due to the excessively large obtuse angle between the first part 231 and the second wall part 2322 is avoided. This is beneficial to improving the energy density of the battery cell 20. Therefore, 120°≤A1≤170° ensures better welding quality of the mounting wall 23' and the side wall 213, improves the reliability of the battery cell 20, is compatible with various welding methods, and is beneficial to improving the energy density of the battery cell 20.

[0272] When the obtuse angle between the inner surfaces of the first wall portion 2321 and the second wall portion 2322 is greater than or equal to 120°, and the mounting wall 23' and side wall 213 are welded, if welding is performed from the outer surface of the side wall 213 of the housing 21, the welding process is smoother and the welding quality is better when the welding is performed along the trajectory from the first wall portion 2321 to the second wall portion 2322. This is beneficial to improving the reliability of the battery cell 20. The obtuse angle between the inner surfaces of the first wall portion 2321 and the second wall portion 2322 is greater than or equal to 120°, making the second portion 232 more compact than the first portion 232. The height of the protrusion of the portion 231 in the first direction X is relatively small. When the mounting wall 23' and the side wall 213 are welded, the depth of the recess 233 in the first direction X is also smaller. If the mounting wall 23' and the side wall 213 are welded from the outside of the mounting wall 23', the focal length of the welding equipment changes less. Therefore, good welding quality can be obtained by welding the mounting wall 23' and the side wall 213 from the outside of the side wall 213, or welding the mounting wall 23' and the side wall 213 from the outside of the mounting wall 23'. It can be compatible with both welding the side wall 213 from the outside and welding the mounting wall 23' from the outside, so the equipment has good compatibility. By ensuring that the obtuse angle between the inner surface of the first wall portion 2321 and the inner surface of the second wall portion 2322 is less than or equal to 170°, the problem of insufficient space in the recess 233 to accommodate the tab 222 due to the excessively large obtuse angle between the first wall portion 2321 and the second wall portion 2322 is avoided. This is beneficial to improving the energy density of the battery cell 20. Therefore, 120°≤A2≤170° ensures better welding quality between the mounting wall 23' and the side wall 213, improves the reliability of the battery cell 20, is compatible with various welding methods, and is beneficial to improving the energy density of the battery cell 20.

[0273] In some embodiments, the second portion 232 further includes a first arc transition wall and a second arc transition wall. The first portion 231 and the second wall portion 2322 are connected by the first arc transition portion 2323, and the second wall portion 2322 and the first wall portion 2321 are connected by the second arc transition portion 2324, which further reduces the risk of stress concentration in the transition area between the first portion 231 and the second wall portion 2322 and the transition area between the second wall portion 2322 and the first wall portion 2321.

[0274] In an embodiment where the sidewall 213 includes a main body 221 and a protrusion 2132, the protrusion 2132 has a first end face 21321 in a first direction X. The first end face 21321 includes a first outer surface 213211 and a second outer surface 213212. The second outer surface 213212 connects the first outer surface 213211 and the end face of the main body 2131 facing away from the endwall 212. To match the contours of the edge protrusion 2132 and the second part 232, as... Figure 13As shown, the second outer surface 213212 and the end face of the protrusion 2132 facing away from the end wall 212 are arranged at an obtuse angle, and the first outer surface 213211 and the second outer surface 213212 are also arranged at an obtuse angle. Specifically, the obtuse angle between the second outer surface 213212 and the protrusion 2132 facing away from the end wall 212 is A3, which is the same as A1. The obtuse angle between the second outer surface 213212 and the first outer surface 213211 is A4, which is the same as A2.

[0275] like Figure 3 , Figure 14 As shown, in some embodiments, the mounting wall 23' includes a plurality of first portions 231, the battery cell 20 includes a plurality of electrode terminals 24, the plurality of electrode terminals 24 are respectively disposed on the plurality of first portions 231, and the electrode terminals 24 are electrically connected to the tabs 222.

[0276] Multiple electrode terminals 24 of the battery cell 20 are respectively disposed on multiple first parts 231, which facilitates the reasonable arrangement of electrode terminals 24 on the mounting wall 23', thereby facilitating the connection of the battery cell 20 to the external structure through the motor terminal, so that the battery cell 20 can be charged and discharged stably.

[0277] For example, please continue to refer to Figure 3 , Figure 14 The mounting wall 23' includes two first portions 231 along the second direction Y, and a second portion 232 located between the two first portions 231; the housing 20' includes two first sidewalls 2133 disposed opposite each other along the third direction Z, and the second portion 232 extends to the two first sidewalls 2133 along the third direction Z, and both first sidewalls 2133 are connected to the second portion 232, and the second direction Y, the third direction Z and the first direction X are perpendicular to each other.

[0278] The second part 232 includes a first wall portion 2321 and two second wall portions 2322, which are respectively connected to the two ends of the first wall. Each first part 231 is connected to the first wall portion 2321 through a second wall portion 2322.

[0279] The two opposite edges of the two first parts 231 along the third direction Z and the two opposite edges of the second part 232 along the third direction Z together form the two opposite edges of the mounting wall 23' along the third direction Z.

[0280] The edges of the two first parts 231 on the side opposite to the second part 232 in the second direction Y respectively form two opposite edges of the mounting wall 23' along the second direction Y.

[0281] The housing 21 includes two second sidewalls 2134 arranged opposite each other along the third direction Z, and the two first sidewalls 2133 and the two second sidewalls 2134 together form the sidewalls 213 of the housing 21.

[0282] Two first sidewalls 2133 and one second sidewall 2134 are each connected to a first portion 231, and two first sidewalls 2133 and another second sidewall 2134 are each connected to another first portion 231. The two edges of the second portion 232 along the third direction Z are respectively connected to the two first sidewalls 2133.

[0283] The second part 232 is located between the two first parts 231. Each of the two first parts 231 can be used to set the electrode terminal 24, which facilitates the electrical connection of the electrode terminal 24 of the battery cell 20 with external devices, reduces the risk of external short circuit of the battery cell 20, and improves the reliability of the battery cell 20.

[0284] like Figure 14 As shown, in some other embodiments, the mounting wall 23' includes a plurality of second portions 232, each of which is provided with a corresponding recess.

[0285] The mounting wall 23' includes a plurality of second portions 232, and a plurality of recesses 233 are formed on the inner side of the mounting wall 23', each recess 233 being able to accommodate at least one tab 222.

[0286] The mounting wall 23' includes multiple second parts 232. On the inner side of the mounting wall 23', each second part 232 is formed with a corresponding recess 233. Different polarity tabs 222 can be accommodated in different recesses 233, reducing the risk of short circuit in the battery cell 20 and improving the reliability of the battery cell 20.

[0287] For example, such as Figure 15 As shown, the mounting wall 23' includes two second portions 232 along the second direction Y, with a first portion 231 located between the two second portions 232; the housing 20' includes two first sidewalls 2133 disposed opposite each other along the third direction Z and two second sidewalls 2134 disposed opposite each other along the second direction Y, each second portion 232 extending to the two first sidewalls 2133 and one second sidewall 2134, each of the two first sidewalls 2133 and one second sidewall 2134 being connected to one second portion 232, and each of the two first sidewalls 2133 and the other second sidewall 2134 being connected to the other second portion 232.

[0288] The mounting wall 23' includes two second parts 232. Along the second direction Y, the first part 231 is located between the two second parts 232. The recesses 233 corresponding to the two second parts 232 can respectively accommodate two tabs 222 with opposite polarities, so that the tabs 222 with opposite polarities are separated by the first part 231, reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20.

[0289] like Figure 7 As shown, in some embodiments, the distance between the tab 222 and the edge of the second portion 232 is G, where 0.01mm≤G≤5mm.

[0290] Before the side wall 213 is connected to the mounting wall 23', if the outer peripheral surface of the mounting wall 23' is flush with the outer peripheral surface of the side wall 213, then the distance between the edge of the tab 222 and the second part 232 can be the distance between the tab 222 and the outer surface of the part of the side wall 213 closest to the tab 222. Figure 7 The diagram shows the case where the outer peripheral surface of the mounting wall 23' is flush with the outer peripheral surface of the side wall 213, and the distance between the edge of the tab 222 and the second part 232 is the distance between the outer surface of the tab 222 and the part of the side wall 213 closest to the tab 222.

[0291] Before the side wall 213 is connected to the mounting wall 23', if the outer peripheral surface of the mounting wall 23' is set opposite to the inner peripheral surface of the side wall 213, the distance between the edge of the tab 222 and the second part 232 can be the distance between the tab 222 and the inner surface of the part of the side wall 213 closest to the tab 222.

[0292] For example, G can be 0.01mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, etc.

[0293] By using G≥0.01mm, the distance between the tab 222 and the edge of the second part 232 is large enough to facilitate the tab 222 being accommodated in the recess 233, reducing the risk of interference between the tab 222 and other structures within the casing 20'; by using G≤5mm, the distance between the tab 222 and the edge of the second part 232 is reduced, allowing the internal space of the casing 20' to be fully utilized, which is beneficial to improving the volumetric energy density of the battery cell 20.

[0294] like Figure 3 , Figure 5 , Figures 14-16 As shown, in some embodiments, the second part 232 is provided with an injection hole 2325.

[0295] The electrolyte injection hole 2325 is used to allow electrolyte to enter the casing 20', thereby injecting electrolyte into the battery cell 20. After the electrolyte injection is completed, the electrolyte injection hole 2325 is sealed by the sealing top.

[0296] By setting the injection hole 2325 in the second part 232, the electrolyte can be poured from the tab 222 away from the main body 221 into the electrode assembly during the injection process. This increases the contact area between the electrolyte and the electrode assembly 22 after entering the shell and improves the injection rate, which is beneficial to improving the wetting efficiency of the electrolyte on the electrode assembly 22.

[0297] like Figure 14 As shown, in some embodiments, the housing 20' includes a housing 21 along a first direction X, one end of the housing 21 having an opening 211, and a mounting wall 23' covering the opening 211; the battery cell 20 also includes a first insulating member 26, which covers the outer surface of the housing 21 along the circumference of the opening 211, and the first insulating member 26 includes a flange 261, which covers at least a portion of the outer surface of the mounting wall 23'.

[0298] The first insulating member 26 covers the outer surface of the sidewall 213 of the housing 21 circumferentially around the opening 211. Along the first direction X, the first insulating member 26 extends beyond the sidewall 213 to form one end of the opening 211, forming a flange 261. In some embodiments, the portion of the first insulating member 26 extending beyond the sidewall 213 to form the opening 211 can be folded around the connection between the mounting wall 23' and the sidewall 213 relative to the portion of the first insulating member 26 surrounding the outer periphery of the sidewall 213, forming a folded portion, so that the flange 261 folds to the outer surface of the mounting wall 23', thereby covering at least a portion of the outer surface of the mounting wall 23'.

[0299] The first insulating element 26 covers the entire outer surface of the side wall 213. The flange 261 may cover the entire outer surface of the mounting wall 23' or only a portion of the outer surface of the mounting wall 23'.

[0300] The housing 21 includes an end wall 212, which is disposed opposite to the opening 211 along a first direction X. A side wall 213 surrounds the outer periphery of the end wall 212, and one end of the side wall 213 facing away from the opening 211 is connected to the end wall 212. Along the first direction X, a first insulating member 26 extends beyond the end of the side wall 213 facing away from the opening 211, forming a folded portion (not shown in the figure). In some embodiments, the portion of the first insulating member 26 extending beyond the end of the side wall 213 facing away from the opening 211 can be folded around the connection between the end wall 212 and the side wall 213 relative to the portion of the first insulating member 26 surrounding the outer periphery of the side wall 213, so that the folded portion folds to the outer surface of the end wall 212, thereby covering at least a portion of the outer surface of the end wall 212.

[0301] The first insulating element 26 can be an insulating coating disposed on the outer surface of the housing 21, or it can be a thin film adhered to the outer surface of the housing 21, such as a Mylar film.

[0302] By covering the outer surface of the housing 21 with the first insulating member 26 circumferentially along the opening 211, and with the flanged portion 261 of the first insulating member 26 covering at least a portion of the outer surface of the mounting wall 23', the first insulating member 26 can reduce moisture absorption of the battery cell 20, reduce the corrosive effect of moisture on the battery cell 20, and reduce the risk of contact between the battery cell 20 and the external environment, thus extending the service life of the battery cell 20. It can also reduce the entry of pollutants into the battery cell 20, such as dust, moisture, and other impurities, which could affect the performance of the battery cell 20. Furthermore, it reduces the risk of contact between the battery cell 20 and other hard objects, thereby reducing the risk of damage or short circuits to the battery cell 20 due to external impacts, improving the reliability of the battery cell 20, and consequently improving the reliability of the battery device 100. In addition, the flanged portion 261 of the first insulating member 26 covering at least a portion of the outer surface of the mounting wall 23' reduces the manufacturing difficulty of installing the first insulating member 26 on the outer surface of the housing 21.

[0303] like Figure 14 As shown, in some embodiments, the mounting wall 2323' includes a first portion 231 and a second portion 232. Along the first direction X, the second portion 232 protrudes from the surface of the first portion 231 facing away from the electrode assembly 22, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22. The second portion 232 includes a first wall portion 2321 and a second wall portion 2322. The second wall portion 2322 connects the first portion 231 and the first wall portion 2321. Along the first direction X, the first wall portion 2321 is further away from the main body portion 221 than the first portion 231. The flange portion 261 includes a first region 2611 located in the first portion 231 and a second region 2612 located in the first wall portion 2321. The first region 2611 covers at least a portion of the outer surface of the first portion 231, and the second region 2612 covers at least a portion of the outer surface of the first wall portion 2321. The width of the second region 2612 is smaller than the width of the first region 2611.

[0304] The first region 2611 covers a portion of the outer surface of the first part 231, or the first region 2611 covers the entire outer surface of the first part 231.

[0305] The second region 2612 covers a portion of the outer surface of the first wall portion 2321, or the second region 2612 covers the entire outer surface of the first wall portion 2321.

[0306] The width of the first region 2611 is W1, and the width of the second region 2612 is W2, where W1 > W2.

[0307] When assembling the battery cell 20, insulating parts of the same width can be used. Since the first part 231 is farther away from the main body 221 than the first wall part 2321, the dimension of the side wall 213 corresponding to the first wall part 2321 in the first direction X is greater than the dimension of the side wall 213 corresponding to the first part 231 in the first direction X, so that the width of the flange 261 in the first part 231 is greater than the width of the flange 261 in the first wall part 2321.

[0308] The first region 2611 covers at least a portion of the outer surface of the first part 231, and the second region 2612 covers at least a portion of the outer surface of the first wall part 2321. The width of the second region 2612 is smaller than the width of the first region 2611. During the assembly of the battery cell 20, the first insulating member 26 of equal width can be used, which facilitates manufacturing.

[0309] like Figure 14 As shown, in some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232. Along the first direction X, the second portion 232 protrudes from the surface of the first portion 231 facing away from the electrode assembly 22, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22. The second portion 232 includes a first wall portion 2321 and a second wall portion 2322. The second wall portion 2322 connects the first portion 231 and the first wall portion 2321. Along the first direction X, the first wall portion 2321 is further away from the main body portion 221 than the first portion 231. The flange portion 261 includes a second region 2612 located in the first wall portion 2321. The second region 2612 covers a portion of the outer surface of the first wall portion 2321, and the area of ​​the portion of the outer surface of the first wall portion 2321 not covered by the second region 2612 is larger than the area covered by the second region 2612.

[0310] The area of ​​the portion of the outer surface of the first wall portion 2321 not covered by the second region 2612 is greater than the area covered by the second region 2612. This can be understood as the area of ​​the orthographic projection of the portion of the outer surface of the first wall portion 2321 not covered by the second region 2612 being greater than the area of ​​the portion covered by the second region 2612 in a plane perpendicular to the first direction X.

[0311] The area of ​​the outer surface of the first wall portion 2321 that is not covered by the second region 2612 is larger than the area covered by the second region 2612. That is, a large part of the outer surface of the first wall portion 2321 is not covered by the first insulating member 26, which facilitates the connection of the battery cell 20 to the first wall portion 2321 and other structures (such as the housing 10) to improve the stability of the battery cell 20.

[0312] In some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232. Along a first direction X, the second portion 232 protrudes from the surface of the first portion 231 facing away from the electrode assembly 22, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22. The second portion 232 includes a first wall portion 2321 and a second wall portion 2322, the second wall portion 2322 connecting the first portion 231 and the first wall portion 2321. Along the first direction X, the first wall portion 2321 is positioned relative to the first portion 231. The first part 231 is further away from the main body 221; the flanged part 261 includes a first region 2611 located in the first part 231 and a second region 2612 located in the first wall part 2321. The first region 2611 covers a part of the outer surface of the first part 231, and the second region 2612 covers a part of the outer surface of the first wall part 2321. The area of ​​the outer surface of the first wall part 2321 that is not covered by the second region 2612 is larger than the area of ​​the outer surface of the first part 231 that is not covered by the flanged part 261.

[0313] The area of ​​the outer surface of the first wall portion 2321 that is not covered by the second region 2612 is greater than the area of ​​the outer surface of the first portion 231 that is not covered by the flange portion 261. It can be understood that, in the plane perpendicular to the first direction X, the area of ​​the orthographic projection of the outer surface of the first wall portion 2321 that is not covered by the second region 2612 is greater than the area of ​​the orthographic projection of the outer surface of the first portion 231 that is not covered by the flange portion 261.

[0314] The area of ​​the outer surface of the first wall portion 2321 that is not covered by the second region 2612 is greater than the area of ​​the outer surface of the first portion 231 that is not covered by the flange portion 261. That is, the outer surface of the first wall portion 2321 has a larger area that is not covered by the insulating member, which facilitates the connection of the battery cell 20 to other structures (such as the housing 10) in the first wall portion 2321, thereby improving the stability of the battery cell 20.

[0315] like Figure 16 , Figure 17As shown, the mounting wall 23' includes a first portion 231 and a second portion 232. A recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22. The first portion 231 and the second portion 232 are arranged along the second direction Y and along the third direction Z. The first portion 231 and the second portion 232 have the same size. The battery cell 20 also includes a second insulating member 27, which is connected to the surface of the mounting wall 23' facing the electrode assembly 22. The second insulating member 27 includes a first insulating portion 271 and a second insulating portion 272. Along the first direction X, the second insulating portion 272 protrudes from the first insulating portion 271 and faces away from the surface of the electrode assembly 22. The first insulating portion 271 is disposed corresponding to the first portion 231, and the second insulating portion 272 is disposed corresponding to the second portion 232. Along the third direction Z, the first insulating portion 271 and the second insulating portion 272 have the same size. The first direction X, the second direction Y, and the third direction Z are all in the same direction.

[0316] The outer peripheral surface of the second insulating member 27 includes two end faces disposed opposite each other in the third direction Z. Since the two end faces of the second insulating member 27 are parallel in the third direction Z, the dimensions of the first insulating portion 271 and the second insulating portion 272 are the same in the third direction Z. The dimension of the first insulating portion 271 in the third direction Z is the distance between the two opposite end faces of the first insulating portion 271 in the third direction Z, and the dimension of the second insulating portion 272 in the third direction Z is the distance between the two opposite end faces of the second insulating portion 272 in the third direction Z.

[0317] Along the third direction Z, on the same side of the second insulating member 27, the end faces of the first insulating portion 271 and the second insulating portion 272 are flush. Alternatively, on one side of the second insulating member 27 along the third direction Z, the end faces of the first insulating portion 271 and the second insulating portion 272 are flush, while on the other side of the second insulating member 27, they are not flush. Or, on one side of the second insulating member 27 along the third direction Z, the end faces of the first insulating portion 271 and the second insulating portion 272 are flush, while on the other side of the second insulating member 27, the end faces of the first insulating portion 271 and the second insulating portion 272 are also flush, which allows the first insulating portion 271 and the second insulating portion 272 to have the same dimensions along the third direction Z.

[0318] Along the third direction Z, the size of the first insulating part 271 can be less than or equal to the size of the first part 231, reducing the risk of interference between the second insulating part 27 and the side wall 213.

[0319] Along the third direction Z, the size of the second insulating part 272 can be less than or equal to the size of the second part 232, reducing the risk of interference between the second insulating part 27 and the side wall 213.

[0320] By having the same dimensions for the first insulating portion 271 and the second insulating portion 272 along the third direction Z, it is easy to make the edges of the first insulating portion 271 and the second insulating portion 272 flush along the third direction Z, thereby facilitating the cooperation between the second insulating member 27 and other structures of the battery cell 20, and thus facilitating the assembly of the battery cell 20.

[0321] like Figure 16 , Figure 17 As shown, in some embodiments, the mounting wall 23' includes a first portion 231 and a second portion 232, and a recess 233 is formed on the side of the second portion 232 facing the electrode assembly 22; the battery cell 20 also includes a second insulating member 27, which is connected to the inner surface of the mounting wall 23'; the second insulating member 27 includes a first insulating portion 271 and a second insulating portion 272, and along the first direction X, the second insulating portion 272 protrudes from the surface of the first insulating portion 271 away from the electrode assembly 22, the first insulating portion 271 is disposed corresponding to the first portion 231, and the second insulating portion 272 is disposed corresponding to the second portion 232; both the surface of the first insulating portion 271 facing the electrode assembly 22 and the surface of the second insulating portion 272 facing the electrode assembly 22 are provided with abutting portions 28, which abut against the main body portion 221, and along the first direction X, the surface of the second insulating portion 272 facing the electrode assembly 22 is further away from the main body portion 221 than the surface of the first insulating portion 271 facing the electrode assembly 22.

[0322] A first insulating portion 271 is connected to the surface of the first portion 231 facing the electrode assembly 22, and a second insulating portion 272 is connected to the surface of the second portion 232 facing the electrode assembly 22. Along the first direction X, the second insulating portion 272 protrudes from the surface of the first insulating portion 271 facing the mounting wall 23'. The second insulating portion 272 includes a fourth segment and a fifth segment, the fifth segment connecting the first insulating portion 271 and the fourth segment. Along the first direction X, the fourth segment is further away from the main body portion 221 than the first insulating portion 271.

[0323] The abutment portion 28 and the first insulating portion 271 can be integrally formed. The surface of the second insulating portion 272 facing the electrode assembly 22 is further away from the main body portion 221 than the surface of the abutment portion 28 facing the electrode assembly 22.

[0324] A first insulating portion 271 may be provided with one abutment portion 28, or multiple abutment portions 28 may be provided. For example, as shown... Figure 17As shown, the mounting wall 23' includes two first portions 231 along the second direction Y, and the two first portions 231 are connected to both ends of the second portion 232. The second insulating member 27 includes a second insulating portion 272 and two first insulating portions 271. The two first insulating portions 271 are respectively connected to the opposite ends of the second connecting portion Q2. The two first insulating portions 271 are respectively disposed on the surfaces of the two first portions 231 facing the electrode assembly 22, and the second insulating portion 272 is disposed on the surface of the second portion 232 facing the electrode assembly 22. Each first insulating portion 271 has a contact portion 28 disposed on the surface of the first insulating portion 271 facing the electrode assembly 22. The contact portion 28 is disposed at the end of the first insulating portion 271 away from the second insulating portion 272, reducing the risk of the contact portion 28 disposed on the first insulating portion 271 interfering with the connection between the electrode terminal 24 and the current collector 25.

[0325] A protruding abutment 28 is provided on the surface of the first insulating portion 271 facing the electrode assembly 22. The abutment 28 abuts against the main body portion 221, which can limit the risk of the electrode assembly 22 moving within the housing 21 or reduce the degree of movement of the electrode assembly 22 within the housing 21, thereby improving the reliability of the battery cell 20. Along the first direction X, the surface of the second insulating portion 272 facing the electrode assembly 22 is further away from the main body portion 221 than the surface of the first insulating portion 271 facing the electrode assembly 22, reducing the risk of interference between the second insulating portion 272 and the tab 222.

[0326] In some embodiments, the surface of the second insulating portion 272 facing the electrode assembly 22 may also be provided with abutting portion 28. The abutting portion 28 provided on the second insulating portion 272 abuts against the main body portion 221. Both the first insulating portion 271 and the second insulating portion 272 are provided with abutting portion 28, which can increase the contact area with the main body portion 221 and the uniformity of the pressure on the main body portion 221 from the abutting portion 28, and further reduce the risk of the electrode assembly 22 shifting.

[0327] This application also provides a battery device 100, which includes the battery cell 20 provided in any of the above embodiments.

[0328] The battery cell 20 provided in any of the above embodiments has a high energy density, so that the battery device 100 having the battery cell 20 also has a high energy density.

[0329] This application also provides an electrical device, which includes the battery cell 20 or the battery device 100 provided in any of the above embodiments.

[0330] The battery cell 20 provided in the above embodiments and the battery device 100 provided in the second aspect embodiment both have high energy densities, which is beneficial to improving the power reliability of the power supply device powered by the battery cell 20 or the battery device 100.

[0331] This application embodiment also provides a battery cell 20, which is a prismatic battery. The battery cell 20 includes a housing 21, an electrode assembly 22, an end cap 23, two electrode terminals 24, and two current collectors 25. The housing 21 has an opening 211 along a first direction X. The electrode assembly 22 includes a main body 221 and two tabs 222 with opposite polarities. At least a portion of the main body 221 is housed within the housing 21. Along the first direction X, the two tabs 222 are connected to the end of the main body 221 facing the opening 211. The end cap 23 covers the opening 211 and includes two first parts 231 and a second part 232. The two first parts 231 are respectively connected to the two ends of the second part 232. The second part 232 includes a first wall portion 2321 and two second wall portions 2322. The two second wall portions 2322 are connected to both ends of the first wall portion 2321 along the second direction Y. Each first part 231 is connected to the first wall portion 2321 through a second wall portion 2322. Along the first direction X, the first wall portion 2321 is further away from the main body 221 than the first part 231. The housing 21 has two first sidewalls 2133 opposite each other along the second direction Y and two second sidewalls 2134 opposite each other along the third direction Z. Along the third direction Z, the first part 231 and the second part 232 are directly connected to the two first sidewalls 2133. Along the third direction Z, the ends of the two first parts 231 opposite to the second part 232 are directly connected to the two second sidewalls 2134 respectively. A recess 233 is formed on the first inner surface 2312' of the end cap 23 facing the electrode assembly 22 at a position corresponding to the second portion 232. The recess 233 extends to the edge of the first inner surface 2312' along the third direction Z and extends to the two opposite end faces of the end cap 23 along the third direction Z. At least a portion of each tab 222 is accommodated in the recess 233. The two electrode terminals 24 of the battery cell 20 are respectively disposed on the two first portions 231 and electrically connected to the tabs 222. The first wall portion 2321 and Two first sidewalls 2133 opposite to each other along the third direction Z of the housing 21 are connected to form a first connection portion Q1. Two tabs 222 are electrically connected to two electrode terminals 24 through two current collectors 25 respectively. A portion of each current collector 25 is located in the recess 233 and is located on the side of the tab 222 away from the main body 221. The two current collectors 25 are connected to the two tabs 222 respectively to form two second connection portions Q2. Along the first direction X, the first connection portion Q1 is farther away from the main body 221 than the second connection portion Q2.

[0332] This application embodiment also provides a battery cell 20, which is a prismatic battery. The battery cell 20 includes a housing 21, an electrode assembly 22, an end cap 23, two electrode terminals 24, and two current collectors 25. The housing 21 has an opening 211 along a first direction X. The electrode assembly 22 includes a main body 221 and two tabs 222 with opposite polarities. At least a portion of the main body 221 is housed within the housing 21. Along the first direction X, the two tabs 222 are connected to the end of the main body 221 facing the opening 211. The end cap 23 covers the opening 211 and includes two second parts 232 and a first part 231. The two second parts 232 are respectively connected to the two ends of the first part 231. The second part 232 includes a first wall portion 2321 and a second wall portion 2322. The second wall portion 2322 is connected to one end of the first wall portion 2321 along the second direction Y. Each first part 231 is connected to the first wall portion 2321 through a second wall portion 2322. Along the first direction X, the first wall portion 2321 is further away from the main body 221 than the first part 231. The housing 21 has two first sidewalls 2133 opposite each other along the second direction Y and two second sidewalls 2134 opposite each other along the third direction Z. Along the third direction Z, the first part 231 and the second part 232 are directly connected to the two first sidewalls 2133. Along the third direction Z, the ends of the two first wall portions 2321 opposite to the first part 231 are directly connected to the two second sidewalls 2134 respectively. A recess 233 is formed on the first inner surface 2312' of the end cap 23 facing the electrode assembly 22 at a position corresponding to the second part 232. The recess 233 extends to the edge of the first inner surface 2312' along the third direction Z and the edge located in the second direction Y. The recess 233 extends to the two opposite end faces of the end cap 23 along the third direction Z and to one end of the end cap along the second direction Y. The two tabs 222 are respectively accommodated in the two recesses 233. The two electrode terminals 24 of the battery cell 20 are both disposed in the first part 231 and electrically connected to the tabs 222.A first wall portion 2321 is directly connected to two first sidewalls 2133 opposite to each other in the third direction Z of the housing 21 and to a second sidewall 2134 to form a first connection portion Q1. Another first wall portion 2321 is directly connected to two first sidewalls 2133 opposite to each other in the third direction Z of the housing 21 and to another second sidewall 2134 to form a first connection portion Q1. Two tabs 222 are electrically connected to two electrode terminals 24 respectively through two current collectors 25. A portion of 25 is located in a recess 233 and is located on the side opposite to the main body 221 along with the tab 222 located in the recess 233. A portion of another current collector 25 is located in another recess 233 and is located on the side opposite to the main body 221 along with the tab 222 located in the recess 233. The two current collectors 25 are respectively connected to the two tabs 222 to form two second connecting portions Q2. Along the first direction X, the first connecting portion Q1 is farther away from the main body 221 than the second connecting portion Q2.

[0333] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0334] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The housing includes a mounting wall, the mounting wall being provided with electrode terminals; An electrode assembly is housed within the housing. The electrode assembly includes a main body and a tab. Along a first direction, the tab is connected to the end of the main body facing the mounting wall and is electrically connected to the electrode terminal. The mounting wall has a first inner surface facing the electrode assembly, the first inner surface having a recess that extends to at least one edge of the first inner surface, and at least a portion of the tab is accommodated within the recess.

2. The battery cell as described in claim 1, characterized in that, The mounting wall includes a first part and a second part, wherein a recess is formed on the side of the second part facing the electrode assembly; The first part and the second part are arranged along the second direction and along the third direction. The first part and the second part have the same size, and the first direction, the second direction and the third direction are perpendicular to each other.

3. The battery cell as described in claim 1, characterized in that, The mounting wall includes a first part and a second part, wherein a recess is formed on the side of the second part facing the electrode assembly; The first part and the second part are arranged along the second direction and along the third direction, at least one edge of the first part and the second part are flush, and the first direction, the second direction and the third direction are perpendicular to each other.

4. The battery cell as described in claim 1, characterized in that, The mounting wall includes a first portion and a second portion. Along the first direction, the second portion protrudes from the surface of the first portion opposite to the electrode assembly, and the recess is formed on the side of the second portion facing the electrode assembly.

5. The battery cell as described in claim 4, characterized in that, The battery cell also includes electrode terminals, which are disposed in the first part.

6. The battery cell as described in claim 5, characterized in that, Along the first direction, the second portion protrudes from the surface of the electrode terminal away from the electrode assembly.

7. The battery cell as described in claim 6, characterized in that, Along the first direction, the second portion protrudes from the surface of the electrode terminal away from the electrode assembly by a dimension L, 0.1mm≤L≤5mm.

8. The battery cell as described in claim 4, characterized in that, When viewed along at least one direction perpendicular to the first direction, at least a portion of the tab overlaps with at least a portion of the electrode terminal.

9. The battery cell as described in claim 4, characterized in that, The housing further includes an end wall and a side wall. Along the first direction, the end wall and the mounting wall are disposed opposite to each other. The side wall includes a body portion and a protrusion portion. The body portion surrounds the outer periphery of the end wall. Along the first direction, one end of the body portion is connected to the end wall, and the other end of the body portion is connected to the protrusion portion. The protrusion portion protrudes from one end of the body portion away from the end wall. A portion of the body portion is directly connected to the first portion, and the protrusion portion is directly connected to the second portion.

10. The battery cell as described in claim 4, characterized in that, The housing further includes an end wall and a side wall. The side wall surrounds the outer periphery of the end wall. One end of the side wall is connected to the end wall, and the other end of the side wall forms an opening. The mounting wall covers the opening. The second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, the first wall portion being further away from the main body portion than the first part along the first direction, the first wall portion being connected to the side wall to form a first connecting portion, the first connecting portion being further away from the main body portion than the tab along the first direction.

11. The battery cell as described in claim 10, characterized in that, The electrode terminal is disposed in the first part, and the battery cell further includes a current collector. The current collector connects the tab and the electrode terminal. At least a portion of the current collector is located in the recess and is connected to the tab to form a second connection portion. Along the first direction, the first connection portion is further away from the main body than the second connection portion.

12. The battery cell as described in claim 11, characterized in that, The current collecting component includes a first segment arranged along the first direction with the electrode tab, the first segment being connected to the electrode tab to form a second connecting portion, the first segment being located on the side of the electrode tab away from the main body along the first direction, and the first connecting portion being further away from the main body than the first segment.

13. The battery cell as described in claim 11, characterized in that, Along the first direction, the distance between the first connecting part and the second connecting part is H, where H > 0.

14. The battery cell as described in claim 13, characterized in that, H≥1mm.

15. The battery cell as described in claim 11, characterized in that, The first part is connected to the sidewall to form a third connecting part, and along the first direction, the second connecting part is further away from the main body than the third connecting part.

16. The battery cell as described in claim 10, characterized in that, The first wall portion is welded to the side wall to form the first connection portion.

17. The battery cell as described in claim 16, characterized in that, The mounting wall is welded to the sidewall to form a welded portion, the welded portion extending circumferentially along the opening, the first connecting portion being a part of the welded portion, and in a cross-section of the welded portion perpendicular to its extension direction, the dimension of the first connecting portion along the first direction is smaller than the dimension of the first connecting portion along the thickness direction of the sidewall.

18. The battery cell as described in claim 4, characterized in that, The second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, the first wall portion being further away from the main body portion along the first direction, the outer surface of the first part and the outer surface of the second wall portion being arranged at an obtuse angle; and / or, the inner surface of the first wall portion and the inner surface of the second wall portion being arranged at an obtuse angle.

19. The battery cell as described in claim 18, characterized in that, The obtuse angle between the outer surface of the first portion and the outer surface of the second wall portion is A1, 95°≤A1≤170°; and / or, the obtuse angle between the inner surface of the first wall portion and the inner surface of the second wall portion is A2, 95°≤A2≤170°.

20. The battery cell as described in claim 19, characterized in that, 95°≤A1≤120°; and / or, 95°≤A2≤120°.

21. The battery cell as described in claim 19, characterized in that, 120°≤A1≤170°; and / or, 120°≤A2≤170°.

22. The battery cell as described in claim 2, characterized in that, The mounting wall includes multiple first portions, and the battery cell includes multiple electrode terminals, which are respectively disposed in multiple first portions, and the electrode terminals are electrically connected to the tabs.

23. The battery cell as described in claim 22, characterized in that, The mounting wall includes two first portions along a second direction, with the second portion located between the two first portions; The housing includes two first sidewalls disposed opposite each other along a third direction. Along the third direction, the second portion extends to the two first sidewalls, and both first sidewalls are connected to the second portion. The second direction, the third direction, and the first direction are perpendicular to each other.

24. The battery cell as described in claim 2, characterized in that, The mounting wall includes a plurality of the second portions, each of which is provided with a corresponding recess.

25. The battery cell as described in claim 24, characterized in that, The mounting wall includes two second portions along a second direction, with the first portion located between the two second portions; The housing includes two first sidewalls disposed opposite each other along a third direction and two second sidewalls disposed opposite each other along a second direction. Each second portion extends to the two first sidewalls and one second sidewall. The two first sidewalls and one second sidewall are each connected to one second portion, and the two first sidewalls and the other second sidewall are each connected to the other second portion.

26. The battery cell as described in claim 2, characterized in that, The distance between the electrode tab and the edge of the second part is G, where 0.01mm≤G≤5mm.

27. The battery cell as described in claim 2, characterized in that, The second part is provided with an injection hole.

28. The battery cell according to any one of claims 1-27, characterized in that, The outer casing includes a housing, and along a first direction, one end of the housing has an opening, and the mounting wall cover is disposed at the opening; The battery cell further includes a first insulating member that covers the outer surface of the housing circumferentially along the opening. The first insulating member includes a flange that covers at least a portion of the outer surface of the mounting wall.

29. The battery cell as described in claim 28, characterized in that, The mounting wall includes a first part and a second part. Along a first direction, the second part protrudes from the surface of the first part away from the electrode assembly, and a recess is formed on the side of the second part facing the electrode assembly. The second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, and the first wall portion being further away from the main body portion along the first direction; The flanged portion includes a first region located in the first part and a second region located in the first wall portion. The first region covers at least a portion of the outer surface of the first part, and the second region covers at least a portion of the outer surface of the first wall portion. The width of the second region is smaller than the width of the first region.

30. The battery cell as described in claim 28, characterized in that, The mounting wall includes a first part and a second part. Along a first direction, the second part protrudes from the surface of the first part away from the electrode assembly, and a recess is formed on the side of the second part facing the electrode assembly. The second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, and the first wall portion being further away from the main body portion along the first direction; The flanged portion includes a second region located in the first wall portion, the second region covering a portion of the outer surface of the first wall portion, and the area of ​​the portion of the outer surface of the first wall portion not covered by the second region is larger than the area covered by the second region.

31. The battery cell as described in claim 28, characterized in that, The mounting wall includes a first part and a second part. Along a first direction, the second part protrudes from the surface of the first part away from the electrode assembly, and a recess is formed on the side of the second part facing the electrode assembly. The second part includes a first wall portion and a second wall portion, the second wall portion connecting the first part and the first wall portion, and the first wall portion being further away from the main body portion along the first direction; The flanged portion includes a first region located in the first part and a second region located in the first wall portion. The first region covers a portion of the outer surface of the first part, and the second region covers a portion of the outer surface of the first wall portion. The area of ​​the outer surface of the first wall portion not covered by the second region is greater than the area of ​​the outer surface of the first part not covered by the flanged portion.

32. The battery cell according to any one of claims 1-27, characterized in that, The mounting wall includes a first part and a second part, the second part having a recessed portion on the side facing the electrode assembly, the first part and the second part being arranged along a second direction, and along a third direction, the first part and the second part having the same size; The battery cell further includes a second insulating member, which is connected to the surface of the mounting wall facing the electrode assembly; The second insulating member includes a first insulating portion and a second insulating portion. Along the first direction, the second insulating portion protrudes from the first insulating portion away from the surface of the electrode assembly. The first insulating portion is disposed corresponding to the first portion, and the second insulating portion is disposed corresponding to the second portion. Along the third direction, the first insulating portion and the second insulating portion have the same size. The first direction, the second direction, and the third direction are all mentioned.

33. The battery cell according to any one of claims 1-27, characterized in that, The mounting wall includes a first part and a second part, wherein a recess is formed on the side of the second part facing the electrode assembly; The battery cell further includes a second insulating member, which is connected to the surface of the mounting wall facing the electrode assembly; The second insulating member includes a first insulating portion and a second insulating portion. Along the first direction, the second insulating portion protrudes from the first insulating portion and is disposed away from the surface of the electrode assembly. The first insulating portion is disposed corresponding to the first portion, and the second insulating portion is disposed corresponding to the second portion. The first insulating portion has a protruding abutting portion on the surface facing the electrode assembly, which abuts against the main body portion. Along the first direction, the surface of the second insulating portion facing the electrode assembly is further away from the main body portion than the surface of the first insulating portion facing the electrode assembly.

34. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-33.

35. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1-33 or the battery device as described in claim 34.

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