Battery monomer, battery device and electric device

Abstract

The utility model provides a battery cell, a battery device and a power utilization device. The battery cell includes a housing, an electrode assembly, a first insulator, and a second insulator. The housing has a first wall portion, and the electrode assembly is accommodated in the housing. The electrode assembly comprises a tab and a main body part, and the tab is arranged at one end of the main body part. The first insulating part is at least partially arranged between the electrode assembly and the first wall part, and the first insulating part is used for insulating and isolating the electrode assembly and the first wall part. The second insulating part is at least partially arranged between the main body part and the first wall part, and the material damage temperature of the second insulating part is higher than that of the first insulating part. As the material damage temperature of the second insulating part is higher than the material damage temperature of the first insulating part, when the first insulating part of the battery monomer is melted due to thermal runaway of the battery monomer adjacent to the battery monomer, the second insulating part can still play a role in insulating and isolating the main body part and the first wall part to a certain extent; and the single battery has relatively high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a battery monomer, a battery device and a power consumption device. BACKGROUND

[0002] Batteries are widely used in the field of new energy, for example, electric vehicles, new energy vehicles, etc. New energy vehicles and electric vehicles have become a new trend in the development of the automobile industry. The development of battery technology needs to consider various design factors, such as battery life, energy density, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery also needs to be considered. However, the reliability of the current battery is poor. CONTENT OF THE UTILITY MODEL

[0003] The purpose of the embodiments of the present application is to provide a battery monomer, a battery device and a power consumption device, which aims to improve the problem of poor reliability of the battery in the related art.

[0004] In a first aspect, the embodiments of the present application provide a battery monomer, which comprises a shell, an electrode assembly, a first insulating piece and a second insulating piece, the shell has a first wall part; the electrode assembly is accommodated in the shell, the electrode assembly comprises a tab and a main body part, the tab is arranged at one end of the main body part; the first insulating piece is at least partially arranged between the electrode assembly and the first wall part, and the first insulating piece is used to insulate and isolate the electrode assembly and the first wall part; the second insulating piece is at least partially arranged between the main body part and the first wall part, and the material damage temperature of the second insulating piece is greater than the material damage temperature of the first insulating piece.

[0005] In the above technical solution, the battery monomer is provided with a first insulating piece and a second insulating piece. In normal use, both the first insulating piece and the second insulating piece can insulate and isolate the main body part and the first wall part, reducing the risk of short circuit caused by contact between the main body part and the first wall part. Since the material damage temperature of the second insulating piece is greater than that of the first insulating piece, when another battery monomer adjacent to the battery monomer undergoes thermal runaway, causing the first insulating piece of the battery monomer to melt, the second insulating piece can still insulate and isolate the main body part and the first wall part to some extent, reducing the risk of short circuit caused by contact between the main body part and the first wall part. In this way, even if another battery monomer adjacent to the battery monomer undergoes thermal runaway, it is not easy to cause short circuit of the battery monomer and continue to trigger thermal runaway, which is conducive to limiting thermal diffusion and improving the reliability of the battery monomer.

[0006] As an optional technical solution of the embodiments of the present application, the second insulating piece is connected to the main body part.

[0007] In the technical scheme, the second insulating piece is connected to the main body part, which limits the relative position of the second insulating piece and the main body part to some extent, so that the second insulating piece can be stably positioned between the main body part and the first wall part, thereby insulating and separating the main body part and the first wall part, which is beneficial to improving the reliability of the battery monomer.

[0008] As an optional technical scheme of the embodiment, the second insulating piece is connected to one end of the main body part facing the first wall part.

[0009] In the technical scheme, the second insulating piece is connected to one end of the main body part facing the first wall part, which is beneficial to limiting the relative position of the part of the second insulating piece between the main body part and the first wall part and the main body part, so that the part of the second insulating piece between the main body part and the first wall part can be stably positioned between the main body part and the first wall part, thereby insulating and separating the main body part and the first wall part, which is beneficial to improving the reliability of the battery monomer.

[0010] As an optional technical scheme of the embodiment, the electrode assembly comprises a positive electrode sheet, a separator and a negative electrode sheet, the positive electrode sheet, the separator and the negative electrode sheet are wound or stacked, and the second insulating piece is connected to the separator.

[0011] In the technical scheme, the second insulating piece is connected to the separator, on the one hand, which is beneficial to fixing the separator, maintaining the shape of the separator, reducing the risk of shrinkage of the separator due to high temperature, so that the positive electrode sheet and the negative electrode sheet are not easily exposed, and is beneficial to improving the reliability of the battery monomer. On the other hand, the second insulating piece can prevent heat from being transferred to the separator to some extent, thereby reducing the risk of shrinkage of the separator due to high temperature, so that the positive electrode sheet and the negative electrode sheet are not easily exposed, and is beneficial to improving the reliability of the battery monomer.

[0012] As an optional technical scheme of the embodiment, the second insulating piece is bonded to the separator.

[0013] In the technical scheme, the second insulating piece is bonded to the separator, which simply and conveniently realizes the connection of the second insulating piece to the main body part, is beneficial to limiting the position of the second insulating piece, so that the second insulating piece can stably play the insulation effect. Moreover, the bonding mode is not only beneficial to maintaining the shape of the separator when the second insulating piece is connected to the separator, but also beneficial to maintaining the shape of the second insulating piece, reducing the risk of shrinkage of the separator due to high temperature.

[0014] As an optional technical solution in this application embodiment, the second insulating member includes a first insulating portion and a second insulating portion connected together; along the thickness direction of the first wall portion, the first insulating portion is at least partially disposed between the main body portion and the first wall portion; along a first direction, the main body portion has two opposing first surfaces, the second insulating portion is connected to one of the first surfaces, and the first direction is perpendicular to the thickness direction of the first wall portion.

[0015] In the above technical solution, the first insulating portion is at least partially disposed between the main body and the first wall portion along the thickness direction of the first wall portion. During normal use, both the first insulating member and the first insulating portion can insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Since the material damage temperature of the second insulating member is greater than that of the first insulating member, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the first insulating member of that battery cell to melt, the first insulating portion can still, to a certain extent, insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. The second insulating portion is connected to the first surface. On the one hand, it restricts the relative positions of the first insulating portion and the main body, and the second insulating portion and the main body, to a certain extent, allowing the first insulating portion to be stably positioned between the main body and the first wall portion, thereby insulating and isolating the main body and the first wall portion, which is beneficial to improving the reliability of the battery cell. On the other hand, the second insulating portion can reduce the risk of a short circuit due to contact between the first surface and other components, which is beneficial to improving the reliability of the battery cell.

[0016] As an optional technical solution in this application embodiment, the outer shell includes a second wall portion, which is connected to the first wall portion, and the second wall portion is the wall portion with the largest outer surface area in the outer shell; along the first direction, the second insulating portion is at least partially located between the main body portion and the second wall portion.

[0017] In the above technical solution, the second insulating portion is at least partially located between the main body portion and the second wall portion along the first direction to insulate and isolate the main body portion and the second wall portion. Because the material damage temperature of the second insulating component is high, when another battery cell adjacent to this battery cell experiences thermal runaway, the second insulating portion can still, to a certain extent, insulate and isolate the main body portion and the second wall portion, reducing the risk of a short circuit due to contact between the main body portion and the second wall portion. Thus, even if another battery cell adjacent to this battery cell experiences thermal runaway, it is less likely to cause a short circuit in this battery cell and further trigger thermal runaway, which helps limit heat diffusion and improve the reliability of the battery cell. Furthermore, since the second wall portion has the largest outer surface area in the casing, when another battery cell adjacent to this battery cell experiences thermal runaway, heat can easily be transferred from the second wall portion to the main body portion, causing the insulating component of the main body portion to shrink due to heat. The second insulating portion can, to a certain extent, prevent heat transfer to the main body portion, thereby reducing the risk of the insulating component shrinking due to high temperature, making the positive and negative electrode plates less likely to be exposed, which helps improve the reliability of the battery cell.

[0018] As an optional technical solution in this application embodiment, each electrode assembly is provided with at least one second insulating member. The second insulating member includes two second insulating portions. The first insulating portion connects to the two second insulating portions, and the two second insulating portions are respectively connected to the two first surfaces of the main body.

[0019] In the above technical solution, each electrode assembly is provided with at least one second insulating member, and the two second insulating parts of each second insulating member are respectively connected to the two first surfaces of the main body, so that each electrode assembly can be well protected. Furthermore, during manufacturing, each second insulating member can be individually connected to each electrode assembly, which helps to reduce production difficulty.

[0020] As an optional technical solution in this application embodiment, the battery cell includes a plurality of electrode assemblies stacked along the first direction, and along the first direction, in two adjacent second insulating members, a second insulating portion of one second insulating member is connected to a second insulating portion of the other second insulating member.

[0021] In the above technical solution, by connecting one second insulating part of one second insulating member to one second insulating part of another second insulating member, two adjacent second insulating members can be connected together. In this way, even if the connection between one of the multiple second insulating members and the electrode assembly fails, the relative position between the second insulating member and the electrode assembly can be maintained to a certain extent, so that the second insulating member can insulate and isolate its corresponding electrode assembly and the first wall portion.

[0022] As an optional technical solution in this application embodiment, the battery cell includes a plurality of electrode components stacked along the first direction, wherein two electrode components located at both ends of the first direction are a first electrode component and a second electrode component, respectively; the second insulating member includes two second insulating portions, one second insulating portion is connected to a first surface of the first electrode component away from the second electrode component, and the other second insulating portion is connected to a first surface of the second electrode component away from the first electrode component.

[0023] In the above technical solution, along the thickness direction of the first wall portion, a second insulating member is located between the main body portion of multiple electrode assemblies and the first wall portion. This single second insulating member can achieve insulation isolation between the main body portion and the first wall portion of multiple electrode assemblies, providing good insulation performance. Furthermore, the location of the second insulating member between the main body portion and the first wall portion of multiple electrode assemblies helps reduce the space occupied inside the casing, thus improving the energy density of the battery cell.

[0024] As an optional technical solution in this application embodiment, both the first insulating part and the second insulating part are connected to the main body part.

[0025] In the above technical solution, by connecting both the first insulating part and the second insulating part to the main body, the connection area between the second insulating member and the main body is larger. On the one hand, this better restricts the relative position of the second insulating member and the main body, allowing the second insulating member to be stably positioned between the main body and the first wall, thereby insulating and isolating the main body and the first wall, which is beneficial to improving the reliability of the battery cell. On the other hand, since both the first insulating part and the second insulating part are connected to the main body, the separator can be better fixed, maintaining its shape and reducing the risk of shrinkage due to high temperature. This makes the positive and negative electrode plates less likely to be exposed, which is beneficial to improving the reliability of the battery cell.

[0026] As an optional technical solution in this application embodiment, the main body includes a first end, the first end facing the first wall, the first insulating part and the electrode tab are both disposed on the first end, and the first insulating part and the electrode tab are arranged along the first direction.

[0027] In the above technical solution, by arranging the first insulating part and the electrode tab along the first direction, the first insulating part can not only insulate and isolate the main body and the first wall, but also insulate and isolate the electrode tab and other components to a certain extent, thereby reducing the risk of short circuit caused by contact between the electrode tab and other components, which is beneficial to improving the reliability of the battery cell.

[0028] As an optional technical solution of this application embodiment, the battery cell includes a plurality of electrode components stacked along the first direction, and each electrode component is correspondingly provided with at least one second insulating member; the plurality of electrode components include adjacent first electrode components and second electrode components, the second insulating portion of the second insulating member disposed on the first electrode component is connected to the first surface of the first electrode component facing the second electrode component, and the second insulating portion of the second insulating member disposed on the second electrode component is connected to the first surface of the second electrode component facing the first electrode component.

[0029] In the above technical solution, each electrode assembly is provided with at least one second insulating member, ensuring good protection for each electrode assembly. Furthermore, during manufacturing, each second insulating member can be individually connected to each electrode assembly, reducing production complexity. The second insulating portion of the second insulating member on the first electrode assembly is connected to the first surface of the first electrode assembly facing the second electrode assembly, and the second insulating portion of the second insulating member on the second electrode assembly is connected to the first surface of the second electrode assembly facing the first electrode assembly. Thus, the second insulating member not only insulates and isolates the main body and the first wall portion, but also, to a certain extent, insulates and isolates the tabs from other components, reducing the risk of short circuits caused by contact between the tabs and other components, thereby improving the reliability of the battery cell.

[0030] As an optional technical solution in this application embodiment, the second insulating portion of the second insulating member disposed on the first electrode assembly is connected to the second insulating portion of the second insulating member disposed on the second electrode assembly.

[0031] In the above technical solution, by connecting the second insulating portion of the second insulating member disposed on the first electrode assembly with the second insulating portion of the second insulating member disposed on the second electrode assembly, two adjacent second insulating members can be connected together. In this way, even if the connection between one of the second insulating members and the electrode assembly fails, the relative position of the second insulating member and the electrode assembly can be maintained to a certain extent, so that the second insulating member can insulate and isolate its corresponding electrode assembly and the first wall portion, reducing the risk of short circuit due to contact between the tab and other components, which is beneficial to improving the reliability of the battery cell.

[0032] As an optional technical solution in this application embodiment, the second insulating member includes a third insulating portion, which extends from the first insulating portion in a direction close to the first wall portion, and the third insulating portion is connected to the side of the electrode facing the first insulating portion.

[0033] In the above technical solution, by setting a third insulating part, on the one hand, the electrode tab and other components can be better insulated and isolated, further reducing the risk of short circuit due to contact between the electrode tab and other components, and further improving the protection effect of the electrode tab. On the other hand, connecting the third insulating part to the electrode tab increases the connection area between the second insulating member and the electrode assembly, further reducing the risk of relative movement between the second insulating member and the electrode assembly, so that the second insulating member can be stably located between the main body and the first wall, thereby insulating and isolating the main body and the first wall, which is beneficial to improving the reliability of the battery cell.

[0034] As an optional technical solution in this application embodiment, the electrode assembly includes a positive electrode sheet, an insulating member, and a negative electrode sheet, wherein the positive electrode sheet, the insulating member, and the negative electrode sheet are wound or stacked; the first surface is the surface of the insulating member.

[0035] In the above technical solution, by connecting the second insulating part to the surface of the separator, on the one hand, it helps to fix the separator, maintain its shape, and reduce the risk of the separator shrinking due to high temperature, making the positive and negative electrode plates less likely to be exposed, thus improving the reliability of the battery cell. On the other hand, the second insulating part can, to a certain extent, prevent heat from being transferred to the separator, thereby reducing the risk of the separator shrinking due to high temperature, making the positive and negative electrode plates less likely to be exposed, thus improving the reliability of the battery cell.

[0036] As an optional technical solution in this application embodiment, along the thickness direction of the first wall portion, the first insulating member is at least partially located on the side of the first insulating portion away from the electrode assembly.

[0037] In the above technical solution, by placing the first insulating member at least partially on the side of the first insulating portion away from the electrode assembly, when another battery cell adjacent to the battery cell experiences thermal runaway, causing the first insulating member of the battery cell to melt, the first insulating portion can, to a certain extent, prevent the melted first insulating member from dripping into the electrode assembly, thereby protecting the electrode assembly, reducing the risk of the electrode assembly short-circuiting and further triggering thermal runaway, and improving the reliability of the battery cell.

[0038] As an optional technical solution in this application embodiment, the housing includes a shell and an end cap, the shell has an opening, the end cap closes the opening, and the end cap is the first wall portion; the first insulating member is a lower plastic disposed on the side of the end cap facing the electrode assembly.

[0039] In the above technical solution, the end cap is the first wall portion, and the first insulating component is the lower plastic. During normal use, both the lower plastic and the second insulating component can insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Since the material damage temperature of the second insulating component is higher than that of the lower plastic, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the lower plastic of that battery cell to melt, the second insulating component can still, to a certain extent, insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Thus, even if another battery cell adjacent to this battery cell experiences thermal runaway, it is less likely to cause a short circuit in that battery cell and further trigger thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell.

[0040] As an optional technical solution in this application embodiment, the outer shell includes a housing and an end cap. The housing includes a side wall and a bottom wall. The side wall surrounds the bottom wall, and one end of the side wall away from the bottom wall forms an opening. The end cap closes the opening. The side wall includes the first wall portion or the bottom wall is the first wall portion.

[0041] As an optional technical solution in this application embodiment, the first insulating member is an insulating film covering the electrode assembly.

[0042] In the above technical solution, when the sidewall includes a first wall portion or the bottom wall is a first wall portion, the first insulating member can be an insulating film covering the electrode assembly. During normal use, both the insulating film and the second insulating member can insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Since the material damage temperature of the second insulating member is greater than that of the insulating film, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the insulating film of that battery cell to melt, the second insulating member can still, to a certain extent, insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Thus, even if another battery cell adjacent to this battery cell experiences thermal runaway, it is less likely to cause a short circuit in that battery cell and further trigger thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell.

[0043] As an optional technical solution in this application embodiment, along the thickness direction of the first wall portion, the first insulating member is at least partially located on the side of the first insulating portion facing the electrode assembly.

[0044] In the above technical solution, by placing at least part of the first insulating member on the side of the first insulating portion facing the electrode assembly, assembly is simple and convenient, which helps to reduce production costs.

[0045] As an optional technical solution in this application embodiment, the outer shell includes a housing and an end cap. The housing has an opening, and the end cap closes the opening. The wall portion of the housing opposite to the end cap is the first wall portion. The first insulating member is a base plate that supports the electrode assembly.

[0046] In the above technical solution, when the wall portion opposite the end cap is the first wall portion, the first insulating member can be a base plate supporting the electrode assembly. During normal use, both the base plate and the second insulating member can insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Since the material damage temperature of the second insulating member is greater than that of the base plate, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the base plate of that battery cell to melt, the second insulating member can still, to a certain extent, insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Thus, even if another battery cell adjacent to this battery cell experiences thermal runaway, it is less likely to cause a short circuit in that battery cell and further trigger thermal runaway, which helps limit heat diffusion and improve the reliability of the battery cell.

[0047] As an optional technical solution in this application embodiment, the size of the second insulating part is L along the thickness direction of the first wall portion, satisfying: 3mm≤L≤50mm.

[0048] In the above technical solution, when L≥3mm, the dimension of the second insulating part along the thickness direction of the first wall is relatively large. On the one hand, this allows for a larger connection area between the second insulating part and the main body, restricting the relative positions of the first insulating part and the main body, and the second insulating part and the main body. This ensures that the first insulating part can be stably positioned between the main body and the first wall, thus insulating and isolating the main body and the first wall, which is beneficial for improving the reliability of the battery cell. On the other hand, the insulation effect of the second insulating part is better, reducing the risk of short circuits caused by contact between the main body and other components, which is beneficial for improving the reliability of the battery cell. When L≤50mm, the dimension of the second insulating part along the thickness direction of the first wall is not too large. This is beneficial for reducing the space occupied inside the battery cell, increasing the energy density of the battery cell, facilitating electrolyte wetting of the electrode assembly, and reducing the manufacturing cost of the battery cell. Therefore, when 3mm≤L≤50mm, the reliability and energy density of the battery cell can be balanced, while keeping the manufacturing cost of the battery cell low.

[0049] As an optional technical solution in this application embodiment, 8mm≤L≤15mm.

[0050] In the above technical solution, when L≥8mm, the dimension of the second insulating part along the thickness direction of the first wall is larger. On the one hand, this allows for a larger connection area between the second insulating part and the main body, restricting the relative positions of the first insulating part and the main body, and the second insulating part and the main body. This allows the first insulating part to be more stably positioned between the main body and the first wall, thus insulating and isolating the main body and the first wall, which is beneficial to improving the reliability of the battery cell. On the other hand, the insulation effect of the second insulating part is better, which can further reduce the risk of short circuits caused by contact between the main body and other components, which is beneficial to improving the reliability of the battery cell. When L≤15mm, the dimension of the second insulating part along the thickness direction of the first wall is not too large. This is beneficial to reducing the space occupied inside the battery cell, increasing the energy density of the battery cell, facilitating electrolyte wetting of the electrode assembly, and reducing the manufacturing cost of the battery cell. Therefore, when 8mm≤L≤15mm, it is possible to better balance the reliability and energy density of the battery cell while keeping the manufacturing cost of the battery cell lower.

[0051] As an optional technical solution in this application embodiment, the second insulating member is a flat plate structure.

[0052] In the above technical solution, when the second insulating member is a flat plate structure, on the one hand, it is easier to manufacture the second insulating member and reduces its cost. On the other hand, the second insulating member does not need to extend between the main body and other walls, and it is less likely to form a stepped structure on the outside of the main body, thus reducing stress concentration in the electrode assembly.

[0053] As an optional technical solution in this application embodiment, each electrode assembly is provided with at least one second insulating element.

[0054] In the above technical solution, each electrode assembly is provided with at least one second insulating element, so that each electrode assembly can be well protected.

[0055] As an optional technical solution in this application embodiment, each of the second insulating members is located between the main body portion and the first wall portion of the plurality of electrode assemblies.

[0056] In the above technical solution, one second insulating member can be provided for multiple electrode assemblies. One second insulating member can achieve insulation isolation between the main body and the first wall of multiple electrode assemblies, resulting in good insulation performance. Furthermore, the fact that one second insulating member is located between the main body and the first wall of multiple electrode assemblies helps to reduce the space occupied inside the casing and improves the energy density of the battery cell.

[0057] As an optional technical solution in this application embodiment, along the thickness direction of the first wall portion, the main body portion has a first end facing the first wall portion; the electrode assembly includes two tabs, the two tabs have opposite polarities, and both tabs are disposed at the first end; the first insulating member is at least partially disposed between the first end and the first wall portion, and the second insulating member is at least partially disposed between the first end and the first wall portion.

[0058] In the above technical solution, the first insulating member, the second insulating member, and the two tabs are disposed at the same end of the main body. During normal use, both the first and second insulating members can insulate and isolate the main body and the first wall, reducing the risk of short circuit due to contact between the main body and the first wall. Since the material damage temperature of the second insulating member is greater than that of the first insulating member, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the first insulating member of that battery cell to melt, the second insulating member can still, to a certain extent, insulate and isolate the main body and the first wall, reducing the risk of short circuit due to contact between the main body and the first wall.

[0059] As an optional technical solution in this application embodiment, the two electrodes are spaced apart at the first end along the second direction; along the second direction, a second insulating member is provided between the two electrodes; and / or along the second direction, a second insulating member is provided on the side of one electrode away from the other electrode.

[0060] In the above technical solution, a second insulating element can be provided between the two electrodes along the second direction, and a second insulating element can also be provided on the side of one electrode that is away from the other electrode. In this way, the second insulating element is less likely to interfere with the electrodes and can better insulate and isolate the main body and the first wall.

[0061] As an optional technical solution in this application embodiment, the main body has a first end and a second end disposed opposite to each other, the first end facing the first wall portion; the electrode assembly includes two electrodes with opposite polarities, both electrodes being disposed at the second end; the first insulating member is at least partially disposed between the first end and the first wall portion, and the second insulating member is at least partially disposed between the first end and the first wall portion.

[0062] In the above technical solution, the first insulating member and the second insulating member are disposed between the first end of the main body and the first wall portion, and the two tabs are disposed at the second end of the main body. During normal use, both the first and second insulating members can insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion. Since the material damage temperature of the second insulating member is higher than that of the first insulating member, when another battery cell adjacent to this battery cell experiences thermal runaway, causing the first insulating member of that battery cell to melt, the second insulating member can still, to a certain extent, insulate and isolate the main body and the first wall portion, reducing the risk of a short circuit due to contact between the main body and the first wall portion.

[0063] As an optional technical solution in this application embodiment, the housing includes two first wall portions, which are disposed opposite to each other, and a first insulating member and a second insulating member are disposed between each first wall portion and the main body portion.

[0064] In the above technical solution, a first insulating member and a second insulating member are provided between each first wall portion and the main body portion. During normal use, both the first and second insulating members can insulate and isolate the main body portion and the corresponding first wall portion, reducing the risk of a short circuit due to contact between the main body portion and the corresponding first wall portion. When another battery cell adjacent to this battery cell experiences thermal runaway, causing the first insulating member of that battery cell to melt, the second insulating member can still, to a certain extent, insulate and isolate the main body portion and the corresponding first wall portion, reducing the risk of a short circuit due to contact between the main body portion and the first wall portion, thus improving the reliability of the battery cell.

[0065] As an optional technical solution in this application embodiment, the second insulating member is connected to the first insulating member.

[0066] In the above technical solution, by connecting the second insulating member to the first insulating member, it is beneficial to fix the relative position of the second insulating member, so that the second insulating member can be stably located between the main body and the first wall, thereby insulating and isolating the main body and the first wall, which is beneficial to improving the reliability of the battery cell.

[0067] As an optional technical solution in this application embodiment, the first insulating member is an insulating film covering the electrode assembly, and the second insulating member is connected to the side of the first insulating member facing the main body.

[0068] In the above technical solution, by connecting the second insulating member to the side of the first insulating member facing the main body, when another battery cell adjacent to the battery cell experiences thermal runaway, causing the first insulating member of that battery cell to melt, the second insulating member can, to a certain extent, prevent the melted first insulating member from adhering to the main body, thereby protecting the electrode assembly and reducing the risk of short circuits in the electrode assembly that could further trigger thermal runaway, thus improving the reliability of the battery cell. Furthermore, the second insulating member can also, to a certain extent, prevent heat transfer to the main body, thereby reducing the risk of thermal runaway in the main body.

[0069] As an optional technical solution in this application embodiment, the first insulating member is a base plate that supports the electrode assembly, and the second insulating member is connected to the side of the first insulating member facing the first wall.

[0070] In the above technical solution, when the first insulating member is a base plate supporting the electrode assembly, the second insulating member is connected to the side of the first insulating member facing the first wall portion, so that the base plate can better support the electrode assembly. Furthermore, when the base plate melts, the second insulating member can insulate and isolate the main body and the first wall portion.

[0071] As an optional technical solution in this application embodiment, the first wall portion is the wall portion with the largest outer surface area in the outer shell.

[0072] In the above technical solution, the first wall is the wall with the largest outer surface area in the shell. Since the first wall has the largest outer surface area, it is easier for the first wall to conduct heat and the first insulating member is easier to melt. Therefore, setting a second insulating member between the first wall and the main body has a better effect.

[0073] As an optional technical solution in this application embodiment, the first wall is provided with a pressure relief mechanism, the pressure relief mechanism has a first pressure relief area, the first pressure relief area is used to open when the battery cell is depressurized, and the second insulating member is provided with a through hole at a position corresponding to the first pressure relief area.

[0074] In the above technical solution, by setting through holes at the positions corresponding to the first pressure relief area on the second insulating component, when the battery cell is depressurized, the fluid medium inside the battery cell can flow through the through holes to the first pressure relief area and be released from the first pressure relief area to the outside of the battery cell, which is beneficial to achieve rapid pressure relief of the battery cell and improve the reliability of the battery cell.

[0075] As an optional technical solution in this application embodiment, the first wall portion is provided with a pressure relief mechanism, the pressure relief mechanism has a first pressure relief area, and the second insulating member is provided with a second pressure relief area at a position corresponding to the first pressure relief area. The first pressure relief area and the second pressure relief area are used to open when the battery cell is depressurized.

[0076] In the above technical solution, the second insulating member has a second pressure relief region corresponding to the location of the first pressure relief region. During normal use of the battery cell, the second pressure relief region separates the electrode assembly from the first pressure relief region, preventing the electrolyte inside the casing from easily washing away from the first pressure relief region and affecting its detonation pressure. When the battery cell depressurizes, the second pressure relief region opens, allowing the fluid medium to release pressure from the first pressure relief region through the second insulating member, which helps improve the reliability of the battery cell.

[0077] As an optional technical solution in this application embodiment, the second insulating member is provided with a weak structure, and the second insulating member is configured to crack along the weak structure when the battery cell is depressurized, so as to open the second depressurization area.

[0078] In the above technical solution, by setting a weak structure on the second insulating member to form a weak position, when the battery cell is depressurized, the second insulating member can crack along the weak structure to open the second depressurization area, thereby providing a larger opening for the fluid medium to pass through.

[0079] As an optional technical solution in this application embodiment, the weak structure includes an annular groove disposed in the second insulating member.

[0080] In the above technical solution, an annular groove is provided on the second insulating member to form a weak structure, which is simple and convenient to manufacture and has a low cost. In addition, when the battery cell is depressurized, the second insulating member can open along the entire circumference of the annular groove, thereby forming a large opening, which facilitates the rapid flow of fluid medium through the second insulating member to the depressurization mechanism, enabling the battery cell to depressurize quickly.

[0081] As an optional technical solution in this application embodiment, the weak structure includes a plurality of grooves or through holes spaced circumferentially along the second pressure relief region.

[0082] In the above technical solution, multiple grooves or through holes are arranged circumferentially along the second pressure relief area. The multiple grooves or through holes weaken the strength of the outer periphery of the second pressure relief area, so that when the battery cell is depressurized, the second pressure relief area can be opened quickly, which facilitates the fluid medium to flow quickly through the second insulating member to the pressure relief mechanism, so that the battery cell can be depressurized quickly.

[0083] As an optional technical solution in this application embodiment, the area of ​​the second pressure relief region is smaller than the area of ​​the first pressure relief region.

[0084] In the above technical solution, by making the area of ​​the second pressure relief region smaller than the area of ​​the first pressure relief region, it is beneficial to ensure that the second insulating component effectively insulates and isolates the main body and the first wall. Furthermore, it reduces the risk of the second pressure relief region obstructing the first pressure relief region when it is opened, thereby facilitating rapid pressure relief of the battery cells.

[0085] As an optional technical solution in this application embodiment, the second insulating element is an insulating film.

[0086] In the above technical solution, the second insulating component is an insulating film. The insulating film can effectively insulate and isolate the main body and the first wall without taking up too much space inside the shell, so that the battery cell can still have a high energy density.

[0087] As an optional technical solution in this application embodiment, the thickness of the insulating film is H, which satisfies: 0.01mm≤H≤0.5mm.

[0088] In the above technical solutions, when H ≥ 0.01 mm, the insulating film has a relatively large thickness, making it less prone to breakage and exhibiting good mechanical properties and insulation performance. When H ≤ 0.5 mm, the insulating film thickness is not excessive, which helps to reduce the space occupied by the battery cell and improve the energy density of the battery cell. Therefore, when 0.01 mm ≤ H ≤ 0.5 mm, both the insulation performance of the insulating film and the energy density of the battery cell can be balanced.

[0089] As an optional technical solution in this application embodiment, 0.05mm≤H≤0.2mm.

[0090] In the above technical solutions, when H ≥ 0.05 mm, the insulating film is thicker, less prone to breakage, and exhibits better mechanical properties and insulation performance. When H ≤ 0.2 mm, the insulating film thickness is not excessive, which helps reduce the space occupied by the battery cell and improves the energy density of the battery cell. Therefore, when 0.05 mm ≤ H ≤ 0.2 mm, a better balance can be struck between the insulation performance of the insulating film and the energy density of the battery cell.

[0091] As an optional technical solution in this application embodiment, the material damage temperature of the second insulating element is greater than or equal to 150°C.

[0092] In the above technical solution, by making the material damage temperature of the second insulating component greater than or equal to 150°C, when another battery cell adjacent to the battery cell experiences thermal runaway, the second insulating component is less likely to melt, thus enabling the second insulating component to play an insulating and isolating role and reducing the risk of short circuit in the battery cell.

[0093] As an optional technical solution in this application embodiment, the material damage temperature of the second insulating component is greater than or equal to 250°C.

[0094] In the above technical solution, by making the material damage temperature of the second insulating component greater than or equal to 250°C, when another battery cell adjacent to the battery cell experiences thermal runaway, the second insulating component is less likely to melt, thus enabling the second insulating component to play an insulating and isolating role and reducing the risk of short circuit in the battery cell.

[0095] As an optional technical solution in this application embodiment, the material of the second insulating member includes at least one of polyethylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyimide.

[0096] In the above technical solutions, polyethylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyimide have good high-temperature resistance and good insulation effect. They can insulate and isolate the body part and the first wall part when another battery cell adjacent to the battery cell experiences thermal runaway, thereby reducing the risk of short circuit in the battery cell and improving the reliability of the battery cell.

[0097] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0098] Thirdly, embodiments of this application also provide an electrical device, which includes the aforementioned battery cell, and the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0099] 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.

[0100] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0101] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0102] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0103] Figure 4 Exploded views of a single battery cell provided in some embodiments of this application;

[0104] Figure 5 A top view schematic diagram of a battery cell provided in some embodiments of this application;

[0105] Figure 6 for Figure 5 A cross-sectional view at position AA in the middle;

[0106] Figure 7 This is a schematic diagram of the structure of an electrode assembly provided in some embodiments of this application;

[0107] Figure 8 Exploded views of a battery cell provided in other embodiments of this application;

[0108] Figure 9 Cross-sectional views of a battery cell provided for other embodiments of this application;

[0109] Figure 10 A cross-sectional view of a battery cell provided for some embodiments of this application;

[0110] Figure 11 Exploded views of a battery cell provided in some embodiments of this application;

[0111] Figure 12 A cross-sectional view of a battery cell provided in some embodiments of this application;

[0112] Figure 13 Exploded views of a battery cell provided in some embodiments of this application;

[0113] Figure 14 for Figure 13 A magnified view of position B in the middle;

[0114] Figure 15 This application also provides cross-sectional views of battery cells in some embodiments;

[0115] Figure 16 A cross-sectional view of a battery cell provided for some other embodiments of this application;

[0116] Figure 17 Exploded views of individual battery cells are also provided in some embodiments of this application;

[0117] Figure 18 for Figure 17 A magnified view of position C in the middle;

[0118] Figure 19Exploded views of a battery cell provided for other embodiments of this application;

[0119] Figure 20 Exploded views of a battery cell provided in some other embodiments of this application;

[0120] Figure 21 Exploded views of a single battery cell are also provided in some other embodiments of this application;

[0121] Figure 22 Exploded views of a battery cell provided in some further embodiments of this application;

[0122] Figure 23 Exploded views of a single battery cell are also provided in some embodiments of this application;

[0123] Figure 24 Exploded views of a single battery cell provided in some other embodiments of this application are also provided;

[0124] Figure 25 Exploded views of a battery cell provided in some other embodiments of this application;

[0125] Figure 26 Exploded views of a single battery cell are provided in some other embodiments of this application;

[0126] Figure 27 Exploded views of a battery cell provided for other embodiments of this application;

[0127] Figure 28 Exploded views of a battery cell provided for further embodiments of this application;

[0128] Figure 29 Exploded views of individual battery cells are also provided in some other embodiments of this application;

[0129] Figure 30 Exploded views of a battery cell provided for further embodiments of this application;

[0130] Figure 31 This is a schematic diagram of the structure of the second insulating element provided in some embodiments of this application;

[0131] Figure 32 This is a schematic diagram of the structure of a second insulating element provided for other embodiments of this application.

[0132] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Outer shell; 211-End cap; 212-Shell; 2121-Second wall; 2122-Side wall; 2123-Bottom wall; 213-First wall; 22-Electrode assembly; 221-Main body; 2211-First surface; 2212-Positive electrode; 2213-Separator; 2214-Negative electrode; 2215-First end; 2216-Second end; 222-Taper; 223-First electrode assembly; 224 - Second electrode assembly; 23- First insulating component; 231- Lower plastic; 232- Mylar membrane; 233- Base plate; 24- Second insulating component; 241- First insulating part; 242- Second insulating part; 243- Third insulating part; 244- Through hole; 245- Second pressure relief area; 246- Weak structure; 2461- Annular groove; 25- Electrode terminal; 26- Current collector; 27- Pressure relief mechanism; 271- First pressure relief area; 100- Battery device; 200- Controller; 300- Motor; 1000- Vehicle. Detailed Implementation

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] In this application, "multiple" means two or more (including two).

[0140] 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.

[0141] 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.

[0142] 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.

[0143] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0144] 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.

[0145] 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.).

[0146] 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 0.2 O2 (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 0.05At least one of O2 and its modified compounds.

[0147] 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.

[0148] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0149] 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 electrodes, 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.).

[0150] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0151] 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.

[0152] 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.

[0153] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0160] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0161] In some implementations, the electrode assembly is a stacked structure.

[0162] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0163] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0164] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0165] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0166] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0167] In some implementations, the electrode assembly may be flat or polygonal in shape.

[0168] 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.

[0169] 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, or a composite metal (such as a copper-aluminum composite housing).

[0170] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a sealed structure, it can protect the electrode assembly and prevent, to some extent, electrolyte leakage. When the housing is a non-sealed structure, it can still protect the electrode assembly, and a sealing bag may be included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film.

[0171] As an example, a battery cell can be a prismatic 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.

[0172] The battery apparatus 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.

[0173] 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.

[0174] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0175] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cells housed within the housing.

[0176] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0177] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0178] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0183] The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0184] Batteries typically consist of multiple cells to provide higher voltage and capacity. If one cell experiences thermal runaway, the heat generated can easily be conducted to adjacent cells, causing the lower plastic layer (the insulating material used to insulate the end caps and electrode assemblies) of those adjacent cells to melt. This can lead to direct contact between the end caps and electrode assemblies, causing a short circuit. This further increases the temperature of the cell, ultimately resulting in heat diffusion and poor battery reliability.

[0185] Therefore, this application provides a battery cell, which includes a casing, an electrode assembly, a first insulating member, and a second insulating member. The casing has a first wall, and the electrode assembly is housed within the casing. The electrode assembly includes a tab and a main body, with the tab disposed at one end of the main body. The first insulating member is at least partially disposed between the electrode assembly and the first wall, and serves to insulate and isolate the electrode assembly and the first wall. The second insulating member is at least partially disposed between the main body and the first wall, and the material damage temperature of the second insulating member is greater than that of the first insulating member.

[0186] The battery cell is equipped with a first insulating component and a second insulating component. Under normal use, both components effectively insulate the main body and the first wall, reducing the risk of a short circuit due to contact between the main body and the first wall. Because the material damage temperature of the second insulating component is higher than that of the first, even if a neighboring battery cell experiences thermal runaway, causing the first insulating component of the current battery cell to melt, the second insulating component can still provide insulation between the main body and the first wall to a certain extent, further reducing the risk of a short circuit. Therefore, even if a neighboring battery cell experiences thermal runaway, it is less likely to cause a short circuit in the current battery cell and further thermal runaway, thus limiting heat diffusion and improving the reliability of the battery cell.

[0187] 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.

[0188] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0189] Please refer to Figure 1 , Figure 1This 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.

[0190] 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.

[0191] 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.

[0192] Please refer to Figure 2 , Figure 2 This 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 battery cells 20, the housing 10 being used to house the battery cells 20.

[0193] 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 body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating space.

[0194] 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.

[0195] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0196] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 This is a top view schematic diagram of a battery cell 20 provided in some embodiments of this application. Figure 6 for Figure 5 A cross-sectional view at position AA. This application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, a first insulating member 23, and a second insulating member 24. The housing 21 has a first wall portion 213, and the electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a tab 222 and a body portion 221, with the tab 222 disposed at one end of the body portion 221. The first insulating member 23 is at least partially disposed between the electrode assembly 22 and the first wall portion 213, and serves to insulate and isolate the electrode assembly 22 and the first wall portion 213. The second insulating member 24 is at least partially disposed between the body portion 221 and the first wall portion 213, and the material damage temperature of the second insulating member 24 is greater than that of the first insulating member 23.

[0197] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0198] The housing 21 includes an end cap 211 and a housing 212. The housing 212 has a receiving space with an opening at one end for accommodating the electrode assembly 22. The end cap 211 is connected to the housing 212 and closes the opening.

[0199] End cap 211 refers to a component that covers the opening of housing 212 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 211 can be adapted to the shape of housing 212 to fit it. Optionally, end cap 211 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 211 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved safety performance. The material of end cap 211 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. End cap 211 is also provided with electrode terminals 25, which are used for electrical connection with the tabs 222 of electrode assembly 22 to input or output electrical energy of battery cell 20. Electrode terminals 25 and tabs 222 can be directly connected, for example, electrode terminals 25 and tabs 222 can be directly welded. Electrode terminal 25 and electrode tab 222 can also be indirectly connected, for example, electrode terminal 25 and electrode tab 222 can be indirectly connected through current collector 26.

[0200] The housing 212 is a component used to cooperate with the end cap 211 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 212 and the end cap 211 can be independent components. An opening can be provided on the housing 212, and the end cap 211 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 211 and the housing 212 can be integrated. Specifically, the end cap 211 and the housing 212 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 212, the end cap 211 closes the housing 212. The housing 212 can have various shapes and sizes, such as cuboid or hexagonal prism. Specifically, the shape of the housing 212 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0201] In some embodiments, the housing 212 may have an opening at only one end, with one end cap 211 correspondingly provided. In other embodiments, the housing 212 may have openings at both ends, with two end caps 211 correspondingly provided, the two end caps 211 respectively closing the two opposite openings of the housing 212. Figure 3 and Figure 4 In the embodiment shown, the housing 212 has an opening at only one end, and an end cap 211 is provided accordingly.

[0202] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The casing 21 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive electrode plates 2212 and negative electrode plates 2214, and typically a separator 2213 is provided between the positive electrode plate 2212 and the negative electrode plate 2214. The portions of the positive electrode plate 2212 and the negative electrode plate 2214 containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive electrode plate 2212 and the negative electrode plate 2214 without active material each constitute a tab 222. The positive and negative tabs may be located together at one end of the main body or at opposite ends of the main body 221. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0203] The first wall portion 213 can be an end cap 211 of the outer casing 21, or it can be a wall portion of the housing 212 of the outer casing 21. In some embodiments, in Figure 3 and Figure 4 In this embodiment, the first wall portion 213 is an end cap 211. In other embodiments, the first wall portion 213 may be a bottom wall 2123 of the housing 212 opposite to the end cap 211. In still other embodiments, the first wall portion 213 may also be a side wall 2122 of the housing 212 adjacent to and connected to the end cap 211.

[0204] The first insulating member 23 may be partially or wholly disposed between the electrode assembly 22 and the first wall portion 213. The first insulating member 23 is used to insulate and isolate the electrode assembly 22 and the first wall portion 213 to reduce the risk of short circuit. Please refer to... Figure 3 and Figure 4 In the embodiment shown in the figure, the first wall portion 213 is an end cap 211, and the first insulating member 23 is a lower plastic 231. In other embodiments, the first wall portion 213 is the bottom wall 2123 of the housing 212 opposite to the end cap 211, and the first insulating member 23 can be a bottom support plate 233 or a Mylar membrane 232. In still other embodiments, the first wall portion 213 is the side wall 2122 of the housing 212 adjacent to and connected to the end cap 211, and the first insulating member 23 can be a Mylar membrane 232. Exemplarily, the material of the first insulating member 23 can be plastic, rubber, etc.

[0205] The second insulating member 24 may be partially or wholly disposed between the main body portion 221 and the first wall portion 213 to insulate and isolate the main body portion 221 and the first wall portion 213. When the battery cell 20 is in normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213.

[0206] The material damage temperature of a substance can be either its melting point or its decomposition temperature. A substance undergoes a decomposition reaction at a certain temperature; that temperature is the decomposition temperature. If a substance has both a melting point and a decomposition temperature, the decomposition temperature is its material damage temperature. If a substance only has a melting point and no decomposition temperature, the melting point is its material damage temperature. If a substance only has a decomposition temperature and no melting point, the decomposition temperature is its material damage temperature.

[0207] The material damage temperature of the second insulating component 24 is greater than that of the first insulating component 23. When the battery cell 20 experiences thermal runaway, the first insulating component 23 will reach the material damage temperature first and melt. When the first insulating component 23 melts, the second insulating component 24 can continue to insulate and isolate the main body 221 and the first wall 213, reducing the risk of short circuit when the main body 221 comes into contact with the first wall 213.

[0208] The battery cell 20 is provided with a first insulating member 23 and a second insulating member 24. During normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body 221 and the first wall 213, reducing the risk of a short circuit due to contact between the main body 221 and the first wall 213. Since the material damage temperature of the second insulating member 24 is higher than that of the first insulating member 23, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body 221 and the first wall 213, reducing the risk of a short circuit due to contact between the main body 221 and the first wall 213. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20 and further thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20.

[0209] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the second insulating member 24 is connected to the main body portion 221.

[0210] The second insulating member 24 may be partially connected to the main body 221 and partially separated from the main body 221. Alternatively, the second insulating member 24 may be entirely connected to the main body 221.

[0211] Optionally, the second insulating member 24 is bonded to the main body 221.

[0212] By connecting the second insulating member 24 to the main body 221, the relative position of the second insulating member 24 and the main body 221 is restricted to a certain extent, so that the second insulating member 24 can be stably located between the main body 221 and the first wall 213, thereby insulating and isolating the main body 221 and the first wall 213, which is beneficial to improving the reliability of the battery cell 20.

[0213] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the second insulating member 24 is connected to the end of the main body 221 facing the first wall portion 213.

[0214] The main body 221 has a first end 2215 facing the first wall portion 213, and a second insulating member 24 is connected to the first end 2215. The portion of the second insulating member 24 located between the main body 221 and the first wall portion 213 is connected to the main body 221, and the portion of the second insulating member 24 located outside the main body 221 and the first wall portion 213 can be connected to the main body 221 or separated from the main body 221.

[0215] By connecting the second insulating member 24 to the end of the main body 221 facing the first wall portion 213, it is beneficial to limit the relative position of the portion of the second insulating member 24 located between the main body 221 and the first wall portion 213 with respect to the main body 221. This allows the portion of the second insulating member 24 located between the main body 221 and the first wall portion 213 to be stably positioned between the main body 221 and the first wall portion 213, thereby insulating and isolating the main body 221 and the first wall portion 213, which is beneficial to improving the reliability of the battery cell 20.

[0216] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 7 This is a schematic diagram of the structure of an electrode assembly 22 provided in some embodiments of this application. In some embodiments, the electrode assembly 22 includes a positive electrode 2212, an insulating member 2213 and a negative electrode 2214, which are wound or stacked together, and a second insulating member 24 is connected to the insulating member 2213.

[0217] The outermost layer of the main body 221 is an insulating member 2213, and the second insulating member 24 is connected to the outer surface of the outermost insulating member 2213.

[0218] By connecting the second insulating member 24 to the separator 2213, on the one hand, it helps to fix the separator 2213, maintain its shape, and reduce the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20. On the other hand, the second insulating member 24 can prevent heat from being transferred to the separator 2213 to a certain extent, thereby reducing the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20.

[0219] In some embodiments, the second insulating member 24 is bonded to the insulating member 2213.

[0220] "The second insulating element 24 is bonded to the isolation element 2213" means that the second insulating element 24 is bonded to the outer surface of the outermost isolation element 2213.

[0221] By bonding the second insulating member 24 to the isolating member 2213, the connection of the second insulating member 24 to the main body 221 is achieved simply and conveniently. This helps to limit the position of the second insulating member 24, allowing it to stably perform its insulating effect. Furthermore, the bonding method not only prevents the shape of the isolating member 2213 from being altered when connecting the second insulating member 24 to it, but also helps to maintain the shape of the isolating member 2213, reducing the risk of the isolating member 2213 shrinking due to high temperatures.

[0222] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the second insulating member 24 includes a first insulating portion 241 and a second insulating portion 242 connected together. Along the thickness direction of the first wall portion 213, the first insulating portion 241 is at least partially disposed between the main body portion 221 and the first wall portion 213. Along a first direction, the main body portion 221 has two opposing first surfaces 2211, and the second insulating portion 242 is connected to one of the first surfaces 2211. The first direction is perpendicular to the thickness direction of the first wall portion 213.

[0223] Please refer to Figure 4 and Figure 6 The thickness direction of the first wall portion 213 is the X direction shown in the figure. The first direction is perpendicular to the thickness direction of the first wall portion 213. Figure 4 and Figure 6 In the embodiment shown, the first direction is the Y direction shown in the figure.

[0224] The first insulating portion 241 is the portion of the second insulating member 24 disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213, to insulatingly isolate the main body portion 221 and the first wall portion 213. In some embodiments, a portion of the first insulating portion 241 is disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213. In other embodiments, the entire first insulating portion 241 is disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213.

[0225] The second insulating portion 242 is a portion of the second insulating member 24 disposed on one side of the main body portion 221 along the first direction. The main body portion 221 has two first surfaces 2211 disposed opposite to each other along the first direction, and the second insulating portion 242 is connected to the first surfaces 2211.

[0226] The first insulating part 241 is connected to the second insulating part 242. Optionally, the first insulating part 241 and the second insulating part 242 are integrally formed.

[0227] The first insulating portion 241 is at least partially disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213. During normal use, both the first insulating member 23 and the first insulating portion 241 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Since the material damage temperature of the second insulating member 24 is greater than that of the first insulating member 23, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the first insulating portion 241 can still, to a certain extent, insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. The second insulating portion 242 is connected to the first surface 2211. On the one hand, it restricts the relative positions of the first insulating portion 241 and the main body 221, and the second insulating portion 242 and the main body 221 to a certain extent, so that the first insulating portion 241 can be stably positioned between the main body 221 and the first wall portion 213, thereby insulating and isolating the main body 221 and the first wall portion 213, which is beneficial to improving the reliability of the battery cell 20. On the other hand, the second insulating portion 242 can reduce the risk of short circuits caused by the first surface 2211 contacting other components, which is beneficial to improving the reliability of the battery cell 20.

[0228] Please refer to Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7In some embodiments, the outer casing 21 includes a second wall portion 2121 connected to the first wall portion 213, and the second wall portion 2121 is the wall portion with the largest outer surface area in the outer casing 21. Along the first direction, the second insulating portion 242 is at least partially located between the main body portion 221 and the second wall portion 2121.

[0229] The second wall portion 2121 is the wall portion with the largest outer surface area in the outer shell 21, commonly referred to as the large surface. The first wall portion 213 is adjacent to the second wall portion 2121. Please refer to... Figure 3 and Figure 4 In the embodiment shown in the figure, the first wall portion 213 is an end cap 211. In other embodiments, the first wall portion 213 may also be the bottom wall 2123 of the housing 212.

[0230] A second insulating portion 242 is disposed between the main body portion 221 and the second wall portion 2121 along a first direction, and the second insulating portion 242 is capable of insulating and isolating the main body portion 221 and the second wall portion 2121. In some embodiments, a portion of the second insulating portion 242 is disposed between the main body portion 221 and the second wall portion 2121 along the first direction. In other embodiments, the entire second insulating portion 242 is disposed between the main body portion 221 and the second wall portion 2121 along the first direction.

[0231] The second insulating portion 242 is located at least partially between the main body portion 221 and the second wall portion 2121 along the first direction to insulate the main body portion 221 and the second wall portion 2121. Because the material damage temperature of the second insulating member 24 is relatively high, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, the second insulating portion 242 can still, to a certain extent, insulate the main body portion 221 and the second wall portion 2121, reducing the risk of a short circuit due to contact between the main body portion 221 and the second wall portion 2121. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20, further leading to thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20. Furthermore, since the second wall portion 2121 has the largest outer surface area in the outer casing 21, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, heat can easily be transferred from the second wall portion 2121 to the main body portion 221, causing the insulating member 2213 of the main body portion 221 to shrink due to heat. The second insulating part 242 can prevent heat from being transferred to the main body 221 to a certain extent, thereby reducing the risk of the separator 2213 shrinking due to high temperature, making the positive electrode 2212 and the negative electrode 2214 less likely to be exposed, which is beneficial to improving the reliability of the battery cell 20.

[0232] Please refer to Figure 8 and Figure 9 , Figure 8Exploded view of a battery cell 20 provided for other embodiments of this application. Figure 9 This is a cross-sectional view of a battery cell 20 provided in some other embodiments of this application. In some other embodiments, each electrode assembly 22 is provided with at least one second insulating member 24. The second insulating member 24 includes two second insulating portions 242, a first insulating portion 241 connecting the two second insulating portions 242, and the two second insulating portions 242 are respectively connected to two first surfaces 2211 of the main body portion 221.

[0233] The correspondence between the electrode assembly 22 and the second insulating member 24 can be one-to-one, meaning that there is a one-to-one correspondence between the electrode assembly 22 and the second insulating member 24. Alternatively, the correspondence can be one-to-many, meaning that one electrode assembly 22 can be provided with multiple second insulating members 24. For example, one electrode assembly 22 can be provided with two, three, four, or more second insulating members 24.

[0234] Each second insulating element 24 includes a first insulating portion 241 and two second insulating portions 242. The first insulating portion 241 connects to the two second insulating portions 242. The two second insulating portions 242 are arranged opposite to each other along a first direction. The two second insulating portions 242 are respectively connected to two first surfaces 2211 of the main body portion 221 of an electrode assembly 22.

[0235] Each electrode assembly 22 is provided with at least one second insulating member 24. The two second insulating portions 242 of each second insulating member 24 are respectively connected to the two first surfaces 2211 of the main body 221, so that each electrode assembly 22 can be well protected. Furthermore, during manufacturing, each second insulating member 24 can be individually connected to each electrode assembly 22, which helps to reduce production difficulty.

[0236] Please refer to Figure 10 , Figure 10 This is a cross-sectional view of a battery cell 20 provided for some embodiments of this application. In some embodiments, the battery cell 20 includes a plurality of electrode assemblies 22 stacked along a first direction. Along the first direction, in two adjacent second insulating members 24, a second insulating portion 242 of one second insulating member 24 is connected to a second insulating portion 242 of the other second insulating member 24.

[0237] The battery cell 20 may include two electrode assemblies 22, three electrode assemblies 22, four electrode assemblies 22, or more electrode assemblies 22. The multiple electrode assemblies 22 are stacked along a first direction.

[0238] Each electrode assembly 22 is provided with at least one second insulating member 24, and a plurality of second insulating members 24 are arranged along a first direction. In two adjacent second insulating members 24, a second insulating portion 242 of one second insulating member 24 is located between the two adjacent electrode assemblies 22, and the second insulating portion 242 of one second insulating member 24 is connected to the second insulating portion 242 of the other second insulating member 24.

[0239] Optionally, a second insulating portion 242 of one second insulating member 24 is bonded to a second insulating portion 242 of another second insulating member 24.

[0240] By connecting one second insulating portion 242 of one second insulating member 24 to one second insulating portion 242 of another second insulating member 24, adjacent second insulating members 24 can be connected together. In this way, even if the connection between one of the multiple second insulating members 24 and the electrode assembly 22 fails, the relative position between the second insulating member 24 and the electrode assembly 22 can be maintained to a certain extent, so that the second insulating member 24 can insulate and isolate its corresponding electrode assembly 22 and the first wall portion 213.

[0241] Please refer to Figure 11 and Figure 12 , Figure 11 An exploded view of a battery cell 20 provided for some embodiments of this application. Figure 12 This is a cross-sectional view of a battery cell 20 provided in some embodiments of this application. In some embodiments, the battery cell 20 includes a plurality of electrode assemblies 22 stacked along a first direction, wherein two electrode assemblies 22 located at opposite ends of the first direction are a first electrode assembly 223 and a second electrode assembly 224, respectively. The second insulating member 24 includes two second insulating portions 242, one second insulating portion 242 being connected to a first surface 2211 of the first electrode assembly 223 facing away from the second electrode assembly 224, and the other second insulating portion 242 being connected to a first surface 2211 of the second electrode assembly 224 facing away from the first electrode assembly 223.

[0242] The battery cell 20 may include two, three, four, or more electrode assemblies 22. The multiple electrode assemblies 22 are stacked along a first direction. Among the multiple electrode assemblies 22, the two electrode assemblies 22 located at opposite ends of the first direction are respectively the first electrode assembly 223 and the second electrode assembly 224.

[0243] The second insulating member 24 includes a first insulating portion 241 and two second insulating portions 242. The first insulating portion 241 connects to the two second insulating portions 242, which are disposed opposite to each other along a first direction. The two second insulating portions 242 are respectively connected to the first electrode assembly 223 and the second electrode assembly 224. Specifically, along the first direction, one second insulating portion 242 is connected to a first surface 2211 of the first electrode assembly 223 facing away from the second electrode assembly 224, and the other second insulating portion 242 is connected to a first surface 2211 of the second electrode assembly 224 facing away from the first electrode assembly 223. Along the thickness direction of the first wall portion 213, the first insulating portion 241 is located between the main body portion 221 of the plurality of electrode assemblies 22 and the first wall portion 213.

[0244] Along the thickness direction of the first wall portion 213, a second insulating member 24 is located between the main body portion 221 of the plurality of electrode assemblies 22 and the first wall portion 213. This single second insulating member 24 achieves insulation isolation between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22, providing good insulation performance. Furthermore, the location of the second insulating member 24 between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22 also helps to reduce the space occupied inside the casing 21, which is beneficial for increasing the energy density of the battery cell 20.

[0245] Please refer to Figure 11 and Figure 12 In some embodiments, the first insulating part 241 and the second insulating part 242 are both connected to the main body part 221.

[0246] The first insulating part 241 is connected to the end of the main body 221 facing the first wall part 213, and the second insulating part 242 is connected to the first surface 2211 of the main body 221.

[0247] In some embodiments, the first insulating portion 241 and the second insulating portion 242 are both connected to the insulating member 2213.

[0248] By connecting both the first insulating portion 241 and the second insulating portion 242 to the main body portion 221, the connection area between the second insulating member 24 and the main body portion 221 is larger. On the one hand, this better restricts the relative position of the second insulating member 24 and the main body portion 221, allowing the second insulating member 24 to be stably positioned between the main body portion 221 and the first wall portion 213, thereby insulating and isolating the main body portion 221 and the first wall portion 213, which is beneficial to improving the reliability of the battery cell 20. On the other hand, the fact that both the first insulating portion 241 and the second insulating portion 242 are connected to the main body portion 221 better fixes the separator 2213, maintains the shape of the separator 2213, reduces the risk of the separator 2213 shrinking due to high temperature, and makes the positive electrode 2212 and the negative electrode 2214 less likely to be exposed, which is beneficial to improving the reliability of the battery cell 20.

[0249] Please refer to Figure 13 and Figure 14 , Figure 13 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 14 for Figure 13 Enlarged view of position B. In some embodiments, the main body 221 includes a first end 2215 facing the first wall portion 213. A first insulating portion 241 and a tab 222 are both disposed at the first end 2215, and the first insulating portion 241 and the tab 222 are arranged along a first direction.

[0250] The main body 221 has a first end 2215 facing the first wall portion 213, and both the first insulating portion 241 and the electrode tab 222 are disposed at the first end 2215. In other words, the first insulating portion 241 and the electrode tab 222 are disposed at the same end of the main body 221.

[0251] Along the first direction, the first insulating part 241 is disposed on one side of the tab 222. The first insulating part 241 may contact the tab 222 or may not contact the tab 222.

[0252] By arranging the first insulating portion 241 and the tab 222 along the first direction, the first insulating portion 241 can not only insulate and isolate the main body portion 221 and the first wall portion 213, but also insulate and isolate the tab 222 and other components to a certain extent, reducing the risk of short circuit due to contact between the tab 222 and other components, which is beneficial to improving the reliability of the battery cell 20.

[0253] Please refer to Figure 13 , Figure 14 and Figure 15 , Figure 15 This application also provides a cross-sectional view of a battery cell 20 according to some embodiments. In some embodiments, the battery cell 20 includes a plurality of electrode assemblies 22 stacked along a first direction, and each electrode assembly 22 is provided with at least one second insulating member 24. The plurality of electrode assemblies 22 include adjacent first electrode assemblies 223 and second electrode assemblies 224. A second insulating portion 242 disposed on the second insulating member 24 of the first electrode assembly 223 is connected to a first surface 2211 of the first electrode assembly 223 facing the second electrode assembly 224, and a second insulating portion 242 disposed on the second insulating member 24 of the second electrode assembly 224 is connected to a first surface 2211 of the second electrode assembly 224 facing the first electrode assembly 223.

[0254] The battery cell 20 may include two, three, four, or more electrode assemblies 22. The multiple electrode assemblies 22 are stacked along a first direction. Each electrode assembly 22 includes a first electrode assembly 223 and a second electrode assembly 224, which are adjacent to each other.

[0255] The second insulating portion 242 of the second insulating member 24 disposed on the first electrode assembly 223 and the second insulating portion 242 of the second insulating member 24 disposed on the second electrode assembly 224 are located between the main body portion 221 of the first electrode assembly 223 and the main body portion 221 of the second electrode assembly 224.

[0256] Each electrode assembly 22 is provided with at least one second insulating member 24, ensuring good protection for each electrode assembly 22. Furthermore, during manufacturing, each second insulating member 24 can be individually connected to each electrode assembly 22, reducing production complexity. The second insulating portion 242 of the second insulating member 24 located on the first electrode assembly 223 is connected to the first surface 2211 of the first electrode assembly 223 facing the second electrode assembly 224, and the second insulating portion 242 of the second insulating member 24 located on the second electrode assembly 224 is connected to the first surface 2211 of the second electrode assembly 224 facing the first electrode assembly 223. Thus, the second insulating member 24 not only insulates and isolates the main body 221 and the first wall 213, but also, to a certain extent, insulates and isolates the tab 222 from other components, reducing the risk of short circuits due to contact between the tab 222 and other components, thereby improving the reliability of the battery cell 20.

[0257] Please refer to Figure 16 , Figure 16 This is a cross-sectional view of a battery cell 20 provided in some other embodiments of this application. In some embodiments, the second insulating portion 242 of the second insulating member 24 disposed on the first electrode assembly 223 is connected to the second insulating portion 242 of the second insulating member 24 disposed on the second electrode assembly 224.

[0258] Two second insulating portions 242 located between the main body portion 221 of the first electrode assembly 223 and the main body portion 221 of the second electrode assembly 224 are connected. For example, the second insulating portion 242 of the second insulating member 24 provided in the first electrode assembly 223 is bonded to the second insulating portion 242 of the second insulating member 24 provided in the second electrode assembly 224.

[0259] By connecting the second insulating portion 242 of the second insulating member 24 disposed on the first electrode assembly 223 with the second insulating portion 242 of the second insulating member 24 disposed on the second electrode assembly 224, two adjacent second insulating members 24 can be connected together. In this way, even if the connection between one of the second insulating members 24 and the electrode assembly 22 fails, the relative position of the second insulating member 24 and the electrode assembly 22 can be maintained to a certain extent, so that the second insulating member 24 can insulate and isolate its corresponding electrode assembly 22 and the first wall portion 213, reducing the risk of short circuit due to contact between the tab 222 and other components, which is beneficial to improving the reliability of the battery cell 20.

[0260] Please refer to Figure 17 and Figure 18 , Figure 17 Exploded views of the battery cell 20 provided in some embodiments of this application are also provided. Figure 18 for Figure 17 Enlarged view of position C. In some embodiments, the second insulating member 24 includes a third insulating portion 243 that extends from the first insulating portion 241 in a direction close to the first wall portion 213. The third insulating portion 243 is connected to the side of the tab 222 facing the first insulating portion 241.

[0261] The third insulating portion 243 is the part of the second insulating member 24 that is connected to the tab 222. The second insulating member 24 includes a first insulating portion 241, a second insulating portion 242, and a third insulating portion 243. The first insulating portion 241 connects the second insulating portion 242 and the third insulating portion 243. The second insulating portion 242 extends from the first insulating portion 241 in a direction away from the first wall portion 213 and is connected to the first surface 2211. The third insulating portion 243 extends from the first insulating portion 241 in a direction close to the first wall portion 213 and is connected to the tab 222.

[0262] Optionally, the first insulating part 241, the second insulating part 242 and the third insulating part 243 are integrally formed.

[0263] By providing the third insulating part 243, on the one hand, the tab 222 and other components can be better insulated and isolated, further reducing the risk of short circuit due to contact between the tab 222 and other components, and further improving the protection effect of the tab 222. On the other hand, by connecting the third insulating part 243 to the tab 222, the connection area between the second insulating member 24 and the electrode assembly 22 is increased, further reducing the risk of relative movement between the second insulating member 24 and the electrode assembly 22, so that the second insulating member 24 can be stably located between the main body 221 and the first wall 213, thereby insulating and isolating the main body 221 and the first wall 213, which is beneficial to improving the reliability of the battery cell 20.

[0264] In some embodiments, the electrode assembly 22 includes a positive electrode 2212, an insulating member 2213, and a negative electrode 2214, which are wound or stacked. The first surface 2211 is the surface of the insulating member 2213.

[0265] The first surface 2211 is the outer surface of the outermost insulating member 2213, and the second insulating part 242 is connected to the first surface 2211.

[0266] By connecting the second insulating portion 242 to the surface of the separator 2213, on the one hand, it helps to fix the separator 2213, maintain its shape, and reduce the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20. On the other hand, the second insulating portion 242 can prevent heat from being transferred to the separator 2213 to a certain extent, thereby reducing the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20.

[0267] Please refer to Figure 17 and Figure 18 In some embodiments, along the thickness direction of the first wall portion 213, the first insulating member 23 is at least partially located on the side of the first insulating portion 241 opposite to the electrode assembly 22.

[0268] Along the thickness direction of the first wall portion 213, the first insulating member 23 may be partially located on the side of the first insulating portion 241 away from the electrode assembly 22, or the first insulating member 23 may be entirely located on the side of the first insulating portion 241 away from the electrode assembly 22.

[0269] Along the thickness direction of the first wall portion 213, the first insulating portion 241 is closer to the main body portion 221 than the first insulating member 23.

[0270] By positioning the first insulating member 23 at least partially on the side of the first insulating portion 241 away from the electrode assembly 22, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, causing the first insulating member 23 of the battery cell 20 to melt, the first insulating portion 241 can, to a certain extent, prevent the melted first insulating member 23 from dripping into the electrode assembly 22, thereby protecting the electrode assembly 22, reducing the risk of the electrode assembly 22 short-circuiting and further triggering thermal runaway, and improving the reliability of the battery cell 20.

[0271] Please refer to Figure 17 and Figure 18In some embodiments, the housing 21 includes a housing 212 and an end cap 211, the housing 212 having an opening and the end cap 211 closing the opening. The end cap 211 is a first wall portion 213. The first insulating member 23 is a lower plastic 231 disposed on the side of the end cap 211 facing the electrode assembly 22.

[0272] End cap 211 is the first wall portion 213, and first insulating member 23 is the lower plastic 231. During normal use, both the lower plastic 231 and the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Since the material damage temperature of the second insulating member 24 is higher than that of the lower plastic 231, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the lower plastic 231 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20 and further thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20.

[0273] Please refer to Figure 19 and Figure 20 , Figure 19 An exploded view of a battery cell 20 provided for some other embodiments of this application. Figure 20 The following is an exploded view of a battery cell 20 provided in some other embodiments of this application. In some embodiments, the housing 21 includes a shell 212 and an end cap 211. The shell 212 includes a side wall 2122 and a bottom wall 2123. The side wall 2122 surrounds the bottom wall 2123, and one end of the side wall 2122 opposite to the bottom wall 2123 forms an opening. The end cap 211 closes the opening. The side wall 2122 may include a first wall portion 213, or the bottom wall 2123 may be a first wall portion 213.

[0274] The housing 212 includes an integrally formed sidewall 2122 and a bottom wall 2123, meaning that the housing 212 is manufactured using an integral molding process, such as stamping, casting, or extrusion molding. In other words, the sidewall 2122 and the bottom wall 2123 of the housing 212 are a single-piece structure. The sidewall 2122 is arranged circumferentially along the bottom wall 2123. One end of the sidewall 2122 is connected to the bottom wall 2123, and the other end of the sidewall 2122 forms an opening. An end cap 211 is connected to the sidewall 2122 and closes the opening.

[0275] Please refer to Figure 19 ,exist Figure 19In the illustrated embodiment, the sidewall 2122 includes a first wall portion 213. In some embodiments, the first wall portion 213 is the wall portion with the smallest outer surface area (i.e., the small facet) in the sidewall 2122. In other embodiments, the first wall portion 213 is the wall portion with the largest outer surface area (i.e., the large facet) in the sidewall 2122. Figure 19 In the embodiment shown, the first wall portion 213 is the wall portion with the smallest outer surface area among the side walls 2122.

[0276] Please refer to Figure 20 ,exist Figure 20 In the embodiment shown, the bottom wall 2123 is the first wall portion 213.

[0277] Please refer to Figure 19 and Figure 20 In some embodiments, the first insulating element 23 is an insulating film covering the electrode assembly 22.

[0278] The first insulating member 23 is an insulating film covering the electrode assembly 22. For example, the first insulating member 23 can be a Mylar film 232 covering the electrode assembly 22. Along the thickness direction of the first wall portion 213, a portion of the first insulating member 23 is located between the second insulating member 24 and the first wall portion 213, that is, a portion of the first insulating member 23 is disposed on the side of the second insulating member 24 facing away from the main body portion 221. In other words, the first insulating member 23 can cover the second insulating member 24 and the main body portion 221.

[0279] When the sidewall 2122 includes a first wall portion 213 or the bottom wall 2123 is a first wall portion 213, the first insulating member 23 can be an insulating film covering the electrode assembly 22. During normal use, both the insulating film and the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Since the material damage temperature of the second insulating member 24 is greater than that of the insulating film, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the insulating film of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20 and further trigger thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20.

[0280] Please refer to Figure 21 , Figure 21An exploded view of the battery cell 20 provided in some other embodiments of this application is shown. In some embodiments, along the thickness direction of the first wall portion 213, the first insulating member 23 is at least partially located on the side of the first insulating portion 241 facing the electrode assembly 22.

[0281] Along the thickness direction of the first wall portion 213, the first insulating member 23 may be partially located on the side of the first insulating portion 241 facing the electrode assembly 22, or the first insulating member 23 may be entirely located on the side of the first insulating portion 241 facing the electrode assembly 22.

[0282] Along the thickness direction of the first wall portion 213, the first insulating portion 241 is further away from the main body portion 221 than the first insulating member 23.

[0283] By positioning the first insulating member 23 at least partially on the side of the first insulating portion 241 facing the electrode assembly 22, assembly is simple and convenient, which helps to reduce production costs.

[0284] Please refer to Figure 21 In some embodiments, the housing 21 includes a housing 212 and an end cap 211. The housing 212 has an opening, and the end cap 211 closes the opening. The wall portion of the housing 212 opposite to the end cap 211 is a first wall portion 213. The first insulating member 23 is a base plate 233 that supports the electrode assembly 22.

[0285] "The wall portion of the housing 212 opposite to the end cap 211 is the first wall portion 213", that is, the bottom wall 2123 of the housing 212 is the first wall portion 213.

[0286] The first insulating member 23 is the base plate 233 supporting the electrode assembly 22, that is, the first insulating member 23 is a plate structure, and the first insulating member 23 supports the electrode assembly 22 along the direction of gravity.

[0287] When the wall portion opposite the end cap 211 of the housing 212 is the first wall portion 213, the first insulating member 23 can be the base plate 233 supporting the electrode assembly 22. During normal use, both the base plate 233 and the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Since the material damage temperature of the second insulating member 24 is greater than that of the base plate 233, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the base plate 233 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20 and further thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20.

[0288] Please refer to this again. Figure 6 and Figure 9 In some embodiments, the size of the second insulating portion 242 is L along the thickness direction of the first wall portion 213, satisfying: 3mm≤L≤50mm.

[0289] L represents the dimension of the second insulating portion 242 along the thickness direction of the first wall portion 213. During measurement, the distance between the two ends of the second insulating portion 242 along the thickness direction of the first wall portion 213 can be measured, and multiple measurements can be taken and the average value can be taken as L.

[0290] The dimensions of the second insulating part 242 along the thickness direction of the first wall part 213 can be: L = 3mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, etc.

[0291] When L ≥ 3mm, the second insulating portion 242 has a larger dimension along the thickness direction of the first wall portion 213. On the one hand, this allows for a larger connection area between the second insulating member 24 and the main body portion 221, restricting the relative positions of the first insulating portion 241 and the main body portion 221, and the second insulating portion 242 and the main body portion 221. This ensures that the first insulating portion 241 can be stably positioned between the main body portion 221 and the first wall portion 213, thereby insulating and isolating the main body portion 221 and the first wall portion 213, which is beneficial for improving the reliability of the battery cell 20. On the other hand, the second insulating portion 242 has a better insulation effect, which can reduce the risk of short circuits caused by the main body portion 221 contacting other components, which is beneficial for improving the reliability of the battery cell 20. When L ≤ 50mm, the dimension of the second insulating portion 242 along the thickness direction of the first wall portion 213 is not too large. This is beneficial for reducing the space occupied by the battery cell 20, increasing the energy density of the battery cell 20, facilitating electrolyte wetting of the electrode assembly 22, and reducing the manufacturing cost of the battery cell 20. Therefore, when 3mm≤L≤50mm, the reliability and energy density of the battery cell 20 can be balanced, and the manufacturing cost of the battery cell 20 is kept low.

[0292] Optionally, 8mm≤L≤15mm.

[0293] The dimensions of the second insulating portion 242 along the thickness direction of the first wall portion 213 can be: L = 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc.

[0294] When L ≥ 8 mm, the second insulating portion 242 has a larger dimension along the thickness direction of the first wall portion 213. On the one hand, this allows for a larger connection area between the second insulating member 24 and the main body portion 221, restricting the relative positions of the first insulating portion 241 and the main body portion 221, and the second insulating portion 242 and the main body portion 221. This allows the first insulating portion 241 to be more stably positioned between the main body portion 221 and the first wall portion 213, thereby insulating and isolating the main body portion 221 and the first wall portion 213, which is beneficial for improving the reliability of the battery cell 20. On the other hand, the second insulating portion 242 has a better insulation effect, which can further reduce the risk of short circuits caused by the main body portion 221 contacting other components, which is beneficial for improving the reliability of the battery cell 20. When L ≤ 15 mm, the dimension of the second insulating portion 242 along the thickness direction of the first wall portion 213 is not too large. This is beneficial for reducing the space occupied inside the battery cell 20, increasing the energy density of the battery cell 20, facilitating electrolyte wetting of the electrode assembly 22, and reducing the manufacturing cost of the battery cell 20. Therefore, when 8mm≤L≤15mm, it is possible to better balance the reliability and energy density of the battery cell 20, and to reduce the manufacturing cost of the battery cell 20.

[0295] Please refer toFigure 22 , Figure 22 This is an exploded view of a battery cell 20 provided in some embodiments of this application. In some embodiments, the second insulating member 24 has a flat plate structure.

[0296] A flat plate structure refers to a structure enclosed by two parallel planes and a cylindrical or prismatic face perpendicular to these two parallel planes. Please refer to [reference needed]. Figure 22 The two parallel surfaces are arranged opposite each other along the thickness direction of the first wall portion 213.

[0297] The second insulating element 24 can be a rectangular plate structure, a hexagonal plate structure, a circular plate structure, an elliptical plate structure, etc.

[0298] The thickness of the second insulating element 24 can be set to be relatively small, so that the second insulating element 24 has a thin sheet structure.

[0299] When the second insulating member 24 has a flat plate structure, on the one hand, it is easier to manufacture the second insulating member 24 and reduce the cost of the second insulating member 24. On the other hand, the second insulating member 24 does not need to extend between the main body 221 and other wall parts, and it is less likely to form a stepped structure on the outside of the main body 221, thus reducing stress concentration in the electrode assembly 22.

[0300] Please refer to Figure 22 In some embodiments, each electrode assembly 22 is provided with at least one second insulating element 24.

[0301] The correspondence between the electrode assembly 22 and the second insulating member 24 can be one-to-one, meaning there is a one-to-one correspondence between the electrode assembly 22 and the second insulating member 24. Alternatively, the correspondence can be one-to-many, meaning one electrode assembly 22 can be provided with multiple second insulating members 24. For example, one electrode assembly 22 can be provided with two, three, four, or more second insulating members 24. Multiple second insulating members 24 are located between the main body portion 221 and the first wall portion 213 of the same electrode assembly 22.

[0302] Each electrode assembly 22 is provided with at least one second insulating element 24, so that each electrode assembly 22 can be well protected.

[0303] Please refer to Figure 23 , Figure 23 An exploded view of a battery cell 20 provided in some embodiments of this application is also shown. In some embodiments, each second insulating member 24 is located between the body portion 221 of a plurality of electrode assemblies 22 and the first insulating member 23.

[0304] Each second insulating member 24 is disposed between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22, and each second insulating member 24 is capable of insulating and isolating the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22. In other words, along the thickness direction of the first wall portion 213, the projection of the main body portion 221 of the plurality of electrode assemblies 22 overlaps with the projection of the second insulating member 24. The projection of the main body portion 221 of one electrode assembly 22 may be partially located within the projection of the second insulating member 24 and another part located outside the projection of the second insulating member 24, or the projection of the main body portion 221 of one electrode assembly 22 may be entirely located within the projection of the second insulating member 24.

[0305] One second insulating member 24 can be provided for multiple electrode assemblies 22. One second insulating member 24 can achieve insulation isolation between the main body 221 and the first wall 213 of multiple electrode assemblies 22, and has a good insulation effect. Furthermore, the second insulating member 24 is located between the main body 221 and the first wall 213 of multiple electrode assemblies 22, which also helps to reduce the space occupied inside the casing 21 and improve the energy density of the battery cell 20.

[0306] Please refer to Figure 23 In some embodiments, the main body 221 has a first end 2215 facing the first wall 213 along the thickness direction of the first wall 213. The electrode assembly 22 includes two tabs 222 with opposite polarities, both tabs 222 being disposed at the first end 2215. A first insulating member 23 is at least partially disposed between the first end 2215 and the first wall 213, and a second insulating member 24 is at least partially disposed between the first end 2215 and the first wall 213.

[0307] The electrode assembly 22 includes two tabs 222, one of which is a positive tab and the other of which is a negative tab. The two tabs 222 are disposed at one end of the main body 221 facing the first wall portion 213.

[0308] The first insulating member 23 is at least partially disposed between the first end 2215 and the first wall portion 213, and the second insulating member 24 is at least partially disposed between the first end 2215 and the first wall portion 213. Thus, the first insulating member 23, the second insulating member 24, and the two tabs 222 are disposed at the same end of the main body portion 221.

[0309] The first insulating member 23, the second insulating member 24, and the two tabs 222 are disposed at the same end of the main body 221. During normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body 221 and the first wall 213, reducing the risk of short circuit due to contact between the main body 221 and the first wall 213. Since the material damage temperature of the second insulating member 24 is greater than that of the first insulating member 23, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body 221 and the first wall 213, reducing the risk of short circuit due to contact between the main body 221 and the first wall 213.

[0310] In some embodiments, two tabs 222 are spaced apart at the first end 2215 along a second direction. A second insulating member 24 is provided between the two tabs 222 along the second direction. And / or along the second direction, a second insulating member 24 is provided on the side of one tab 222 opposite to the other tab 222.

[0311] The two tabs 222 are spaced apart along the second direction. Please refer to... Figure 23 The second direction can be the Z direction shown in the figure. In the embodiment shown in the figure, the first direction, the second direction, and the thickness direction of the first wall portion 213 are perpendicular to each other.

[0312] Please refer to Figure 23 Along the second direction, a second insulating element 24 is provided between the two tabs 222.

[0313] Please refer to Figure 24 , Figure 24 Exploded views of the battery cell 20 provided in some further embodiments of this application are also shown. Figure 24 In the illustrated embodiment, along the second direction, a second insulating member 24 is provided on the side of one electrode tab 222 opposite to the other electrode tab 222. Each electrode assembly 22 is provided with two corresponding second insulating members 24, which are located on both sides of the two electrode tabs 222 along the second direction.

[0314] Please refer to Figure 25 , Figure 25 An exploded view of a battery cell 20 provided in some other embodiments of this application. Figure 25 In the illustrated embodiment, a second insulating member 24 is provided between the two tabs 222 along the second direction, and a second insulating member 24 is provided on the side of one tab 222 facing away from the other tab 222. Each electrode assembly 22 is provided with three second insulating members 24, and the second insulating members 24 and the tabs 222 are alternately distributed along the second direction.

[0315] Along the second direction, a second insulating member 24 can be provided between the two tabs 222. A second insulating member 24 can also be provided on the side of one tab 222 away from the other tab 222. In this way, the second insulating member 24 is less likely to interfere with the tabs 222 and can better insulate and isolate the main body 221 and the first wall 213.

[0316] Please refer to Figure 26 , Figure 26 The following is an exploded view of a battery cell 20 provided in some other embodiments of this application. In some embodiments, the main body 221 has a first end 2215 and a second end 2216 disposed opposite to each other, the first end 2215 facing the first wall portion 213. The electrode assembly 22 includes two tabs 222 with opposite polarities, both tabs 222 being disposed at the second end 2216. A first insulating member 23 is at least partially disposed between the first end 2215 and the first wall portion 213, and a second insulating member 24 is at least partially disposed between the first end 2215 and the first wall portion 213.

[0317] The main body 221 has a first end 2215 and a second end 2216 disposed opposite to each other, wherein the first end 2215 faces the first wall portion 213 and the second end 2216 faces away from the first wall portion 213. Two tabs 222 are disposed at the second end 2216. A first insulating member 23 is at least partially disposed between the first end 2215 and the first wall portion 213, and a second insulating member 24 is at least partially disposed between the first end 2215 and the first wall portion 213. That is, the first insulating member 23 and the second insulating member 24 are respectively located at the same end of the main body 221, and the second insulating member 24 and the tabs 222 are respectively located at both ends of the main body 221.

[0318] The first insulating member 23 and the second insulating member 24 are disposed between the first end 2215 of the main body 221 and the first wall portion 213, and the two tabs 222 are disposed at the second end 2216 of the main body 221. During normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body 221 and the first wall portion 213, reducing the risk of short circuit due to contact between the main body 221 and the first wall portion 213. Since the material damage temperature of the second insulating member 24 is greater than that of the first insulating member 23, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body 221 and the first wall portion 213, reducing the risk of short circuit due to contact between the main body 221 and the first wall portion 213.

[0319] Please refer to Figure 27 , Figure 27This is an exploded view of a battery cell 20 provided in some other embodiments of this application. In some embodiments, the housing 21 includes two first wall portions 213 disposed opposite to each other, and a first insulating member 23 and a second insulating member 24 are disposed between each first wall portion 213 and the main body portion 221.

[0320] The outer casing 21 includes two first wall portions 213 disposed opposite to each other, and a first insulating member 23 and a second insulating member 24 are disposed between each first wall portion 213 and the main body portion 221.

[0321] Please refer to Figure 27 ,exist Figure 27 In the illustrated embodiment, both opposite small faces of the housing 212 are first wall portions 213. A first insulating member 23 and a second insulating member 24 are provided between the main body portion 221 and one small face. Here, the first insulating member 23 and the second insulating member 24 located between the main body portion 221 and the small face may be partially located between the main body portion 221 and the small face, or they may be located entirely between the main body portion 221 and the small face. A first insulating member 23 and a second insulating member 24 are also provided between the main body portion 221 and the other small face. Here, the first insulating member 23 and the second insulating member 24 located between the main body portion 221 and the other small face may be partially located between the main body portion 221 and the other small face, or they may be located entirely between the main body portion 221 and the other small face.

[0322] Please refer to Figure 28 , Figure 28 Exploded views of the battery cell 20 provided in some other embodiments of this application. Figure 28 In the illustrated embodiment, both large surfaces of the housing 212 that are opposite to each other are first wall portions 213. A first insulating member 23 and a second insulating member 24 are provided between the main body portion 221 and one of the large surfaces. Here, the first insulating member 23 and the second insulating member 24 located between the main body portion 221 and one of the large surfaces may be located only partially between the main body portion 221 and one of the large surfaces, or they may be located entirely between the main body portion 221 and one of the large surfaces. A first insulating member 23 and a second insulating member 24 are also provided between the main body portion 221 and the other large surface. Here, the first insulating member 23 and the second insulating member 24 located between the main body portion 221 and the other large surface may be located only partially between the main body portion 221 and the other large surface, or they may be located entirely between the main body portion 221 and the other large surface.

[0323] A first insulating member 23 and a second insulating member 24 are provided between each first wall portion 213 and the main body portion 221. During normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body portion 221 from the corresponding first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the corresponding first wall portion 213. When another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body portion 221 from the corresponding first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213, thus improving the reliability of the battery cell 20.

[0324] In some embodiments, the second insulating member 24 is connected to the first insulating member 23.

[0325] Optionally, the second insulating element 24 is bonded to the first insulating element 23.

[0326] By connecting the second insulating member 24 to the first insulating member 23, it is beneficial to fix the relative position of the second insulating member 24, so that the second insulating member 24 can be stably located between the main body 221 and the first wall 213, thereby insulating and isolating the main body 221 and the first wall 213, which is beneficial to improving the reliability of the battery cell 20.

[0327] Please refer to this again. Figure 19 and Figure 20 In some embodiments, the first insulating member 23 is an insulating film covering the electrode assembly 22, and the second insulating member 24 is connected to the side of the first insulating member 23 facing the main body 221.

[0328] When the first insulating member 23 is an insulating film covering the electrode assembly 22, the first insulating member 23 can simultaneously cover the second insulating member 24 and the electrode assembly 22, so that the second insulating member 24 is connected to the side of the first insulating member 23 facing the main body 221.

[0329] Optionally, the second insulating member 24 is bonded to the side of the first insulating member 23 facing the main body 221.

[0330] By connecting the second insulating member 24 to the side of the first insulating member 23 facing the main body 221, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can, to a certain extent, prevent the melted first insulating member 23 from adhering to the main body 221. This protects the electrode assembly 22, reduces the risk of a short circuit in the electrode assembly 22 leading to further thermal runaway, and improves the reliability of the battery cell 20. Furthermore, the second insulating member 24 can also, to a certain extent, prevent heat transfer to the main body 221, thereby reducing the risk of thermal runaway in the main body 221.

[0331] Please refer to Figure 21 In some embodiments, the first insulating member 23 is a base plate 233 supporting the electrode assembly 22, and the second insulating member 24 is connected to the side of the first insulating member 23 facing the first wall portion 213.

[0332] When the first insulating member 23 is the base plate 233 supporting the electrode assembly 22, the second insulating member 24 is at least partially located between the first insulating member 23 and the first wall portion 213, and the portion of the second insulating member 24 located between the first insulating member 23 and the first wall portion 213 is connected to the first insulating member 23.

[0333] When the first insulating member 23 serves as the base plate 233 supporting the electrode assembly 22, the second insulating member 24 is connected to the side of the first insulating member 23 facing the first wall portion 213, so that the base plate 233 can better support the electrode assembly 22. Furthermore, when the base plate 233 melts, the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213.

[0334] Please refer to Figure 28 In some embodiments, the first wall portion 213 is the wall portion with the largest outer surface area in the outer casing 21.

[0335] The first wall portion 213 is the wall portion with the largest outer surface area in the outer shell 21, that is, the first wall portion 213 is the large surface of the outer shell 21.

[0336] The first wall portion 213 has the largest outer surface area in the outer shell 21. Since the first wall portion 213 has the largest outer surface area, it is relatively easier to conduct heat and the first insulating member 23 is relatively easier to melt. Therefore, providing the second insulating member 24 between the first wall portion 213 and the main body portion 221 has a better effect.

[0337] Please refer to Figure 29 , Figure 29Exploded views of the battery cell 20 are also provided for some other embodiments of this application. In some embodiments, a pressure relief mechanism 27 is provided on the first wall portion 213. The pressure relief mechanism 27 has a first pressure relief region 271, which is used to open when the battery cell 20 is depressurized. A through hole 244 is provided on the second insulating member 24 at a position corresponding to the first pressure relief region 271.

[0338] The pressure relief mechanism 27 is a component used to open when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, thereby releasing the internal pressure of the battery cell 20. The pressure relief mechanism 27 can be a component mounted on the first wall portion 213, in which case the pressure relief mechanism 27 and the first wall portion 213 are separately configured and connected. For example, the pressure relief mechanism 27 is an explosion-proof plate mounted on the first wall portion 213. Alternatively, the pressure relief mechanism 27 can be part of the first wall portion 213, in which case the pressure relief mechanism 27 and the first wall portion 213 are integrally formed.

[0339] The pressure relief mechanism 27 has a weak point. When the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the pressure relief mechanism 27 can crack along the weak point to release the internal pressure of the battery cell 20. In some embodiments, the strength of the pressure relief mechanism 27 at the weak point may be lower than the strength at other locations of the pressure relief mechanism 27. This allows the weak point to crack under the internal pressure when the internal pressure or temperature of the battery cell 20 reaches the detonation pressure, thus releasing the internal pressure of the battery cell 20. In other embodiments, the melting point of the pressure relief mechanism 27 at the weak point may be lower than the melting point at other locations of the pressure relief mechanism 27. This allows the weak point to crack under high temperature when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, thus releasing the internal pressure of the battery cell 20.

[0340] The weak part can be a ring-shaped structure, for example, it can be circular or elliptical. The weak part can also be a non-ring-shaped structure, for example, it can be C-shaped or U-shaped.

[0341] The first pressure relief region 271 is the portion of the pressure relief mechanism 27 located within the area enclosed by the weak part. This area, enclosed by the weak part, is the region where the pressure relief mechanism 27 forms an opening after the weak part is damaged by the gas inside the outer casing 21. When the weak part is annular, the area enclosed by the weak part is the region within the annular structure; when the weak part is non-annular, the area enclosed by the weak part is the region within the annulus formed by the weak part itself and the lines connecting its two ends.

[0342] A through hole 244 is provided at a position corresponding to the first pressure relief region 271 on the second insulating member 24. The through hole 244 penetrates the second insulating member 24 along its thickness direction. The size of the through hole 244 can be larger than the size of the first pressure relief region 271, smaller than the size of the first pressure relief region 271, or equal to the size of the first pressure relief region 271.

[0343] By providing a through hole 244 at a position corresponding to the first pressure relief region 271 on the second insulating member 24, when the battery cell 20 is depressurized, the fluid medium inside the battery cell 20 can flow through the through hole 244 to the first pressure relief region 271 and be released from the first pressure relief region 271 to the outside of the battery cell 20, which is beneficial to achieve rapid pressure relief of the battery cell 20 and improve the reliability of the battery cell 20.

[0344] Please refer to Figure 30 , Figure 30 The following is an exploded view of a battery cell 20 provided in some embodiments of this application. In some embodiments, a pressure relief mechanism 27 is provided on a first wall portion 213, the pressure relief mechanism 27 having a first pressure relief region 271. A second pressure relief region 245 is provided on a second insulating member 24 at a position corresponding to the first pressure relief region 271, the first pressure relief region 271 and the second pressure relief region 245 being used to open when the battery cell 20 is depressurized.

[0345] The second insulating member 24 is provided with a second pressure relief region 245, the position of which corresponds to the position of the first pressure relief region 271. The second pressure relief region 245 is used to at least partially open when the battery cell 20 is depressurized, so that the fluid medium located on the side of the second insulating member 24 facing the main body 221 can flow through the second pressure relief region 245 to the pressure relief mechanism 27 and be depressurized through the first pressure relief region 271.

[0346] The second insulating member 24 has a second pressure relief region 245 corresponding to the position of the first pressure relief region 271. During normal use of the battery cell 20, the second pressure relief region 245 separates the electrode assembly 22 from the first pressure relief region 271, preventing the electrolyte inside the casing 21 from easily washing away from the first pressure relief region 271 and affecting its detonation pressure. When the battery cell 20 is depressurized, the second pressure relief region 245 opens, allowing the fluid medium to release pressure from the first pressure relief region 271 through the second insulating member 24, which helps improve the reliability of the battery cell 20.

[0347] Please refer to Figure 30 In some embodiments, the second insulating member 24 is provided with a weak structure 246, and the second insulating member 24 is configured to split along the weak structure 246 when the battery cell 20 is depressurized, so as to open the second depressurization region 245.

[0348] The weak structure 246 is disposed around the outer periphery of the second pressure relief region 245. The weak structure 246 is used to weaken the strength of the second insulating member 24 around the outer periphery of the second pressure relief region 245, so that the second pressure relief region 245 can be opened more easily when the battery cell 20 is depressurized, so that the fluid medium can flow to the pressure relief mechanism 27.

[0349] By providing a weak structure 246 on the second insulating member 24 to form a weak position, when the battery cell 20 is depressurized, the second insulating member 24 can crack along the weak structure 246 to open the second depressurization area 245, thereby providing a larger opening for the fluid medium to pass through.

[0350] Please refer to Figure 31 , Figure 31 This is a schematic diagram of the structure of the second insulating member 24 provided in some embodiments of this application. In some embodiments, the weak structure 246 includes an annular groove 2461 disposed in the second insulating member 24.

[0351] The annular groove 2461 can be a circular groove, an elliptical groove, or a racetrack-shaped groove. The annular groove 2461 can be provided on the side of the second insulating member 24 facing the main body 221, or it can be provided on the side of the second insulating member 24 away from the main body 221.

[0352] By providing an annular groove 2461 on the second insulating member 24 to form a weak structure 246, the manufacturing process is simple, convenient, and cost-effective. Furthermore, when the battery cell 20 is depressurized, the second insulating member 24 can open along the entire circumference of the annular groove 2461, thereby forming a large opening. This facilitates the rapid flow of fluid medium through the second insulating member 24 to the depressurization mechanism 27, enabling the battery cell 20 to depressurize quickly.

[0353] Please refer to Figure 32 , Figure 32 This is a schematic diagram of the structure of the second insulating member 24 provided for other embodiments of this application. In other embodiments, the weak structure 246 includes a plurality of grooves or through holes 244 spaced circumferentially along the second pressure relief region 245.

[0354] The weak structure 246 may include a plurality of grooves spaced circumferentially along the second pressure relief region 245. The plurality of grooves weaken the strength of the second insulator 24 on the outer periphery of the second pressure relief region 245, making the second pressure relief region 245 easier to open when the battery cell 20 is depressurized.

[0355] The weak structure 246 may also include a plurality of through holes 244 spaced circumferentially along the second pressure relief region 245. Along the circumference of the second pressure relief region 245, the remaining portion between two adjacent through holes 244 is relatively weak. This portion can be destroyed when the battery cell 20 is depressurized, thereby opening the second pressure relief region 245.

[0356] Multiple grooves or through holes 244 are spaced apart along the circumference of the second pressure relief region 245. The multiple grooves or through holes 244 weaken the strength of the outer periphery of the second pressure relief region 245, so that the second pressure relief region 245 can be opened quickly when the battery cell 20 is depressurized, so that the fluid medium can flow quickly through the second insulating member 24 to the pressure relief mechanism 27, and the battery cell 20 can be depressurized quickly.

[0357] In some embodiments, the area of ​​the second pressure relief region 245 is smaller than the area of ​​the first pressure relief region 271.

[0358] By making the area of ​​the second pressure relief region 245 smaller than the area of ​​the first pressure relief region 271, on the one hand, it is beneficial to make the second insulating member 24 insulate and isolate the main body 221 and the first wall portion 213. On the other hand, it can reduce the risk of the second pressure relief region 245 blocking the first pressure relief region 271 when it is opened, thereby facilitating the rapid pressure relief of the battery cell 20.

[0359] In some embodiments, the second insulating element 24 is an insulating film.

[0360] Optionally, the second insulating member 24 is a PI film (Polyimide Film) connected to the main body 221.

[0361] The second insulating component 24 is an insulating film. The insulating film can effectively insulate and isolate the main body 221 and the first wall 213, and will not occupy too much space inside the outer casing 21, so that the battery cell 20 can still have a high energy density.

[0362] Please refer to this again. Figure 6 and Figure 9 In some embodiments, the thickness of the insulating film is H, which satisfies: 0.01mm≤H≤0.5mm.

[0363] H represents the thickness of the insulating film. During measurement, multiple measurements can be taken and the average value can be used as H.

[0364] The thickness of the insulating film can be: H = 0.01mm, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc.

[0365] When H ≥ 0.01 mm, the insulating film has a relatively large thickness, making it less prone to breakage and exhibiting good mechanical properties and insulation performance. When H ≤ 0.5 mm, the insulating film thickness is not excessive, which helps to reduce the space occupied by the battery cell 20 and improve the energy density of the battery cell 20. Therefore, when 0.01 mm ≤ H ≤ 0.5 mm, both the insulation performance of the insulating film and the energy density of the battery cell 20 can be balanced.

[0366] Optionally, 0.05mm ≤ H ≤ 0.2mm.

[0367] The thickness of the insulating film can be: H = 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, etc.

[0368] When H ≥ 0.05 mm, the insulating film is thicker, less prone to breakage, and exhibits better mechanical properties and insulation performance. When H ≤ 0.2 mm, the insulating film thickness is not excessive, which helps reduce the space occupied by the battery cell 20 and improves the energy density of the battery cell 20. Therefore, when 0.05 mm ≤ H ≤ 0.2 mm, a better balance can be struck between the insulation performance of the insulating film and the energy density of the battery cell 20.

[0369] In some embodiments, the material damage temperature of the second insulating element 24 is greater than or equal to 150°C.

[0370] By making the material damage temperature of the second insulating element 24 greater than or equal to 150°C, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, the second insulating element 24 is less likely to melt, thus enabling the second insulating element 24 to play an insulating and isolating role and reducing the risk of short circuit in the battery cell 20.

[0371] Optionally, the material damage temperature of the second insulating element 24 is greater than or equal to 250°C.

[0372] By making the material damage temperature of the second insulating element 24 greater than or equal to 250°C, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, the second insulating element 24 is less likely to melt, thus enabling the second insulating element 24 to play an insulating and isolating role and reducing the risk of short circuit in the battery cell 20.

[0373] In some embodiments, the material of the second insulating member 24 includes at least one of polyethylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyimide.

[0374] Polyethylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyimide have good high-temperature resistance and good insulation effect. They can insulate the body part and the first wall part 213 when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, thereby reducing the risk of short circuit of the battery cell 20 and improving the reliability of the battery cell 20.

[0375] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0376] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0377] According to some embodiments of this application, please refer to Figures 3-32 .

[0378] This application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, a first insulating member 23, and a second insulating member 24. The housing 21 has a first wall portion 213, and the electrode assembly 22 is housed within the housing 21. The electrode assembly 22 includes a tab 222 and a main body portion 221, with the tab 222 disposed at one end of the main body portion 221. The first insulating member 23 is at least partially disposed between the electrode assembly 22 and the first wall portion 213, and serves to insulate and isolate the electrode assembly 22 and the first wall portion 213. The second insulating member 24 is at least partially disposed between the main body portion 221 and the first wall portion 213, and the material damage temperature of the second insulating member 24 is greater than that of the first insulating member 23. With the first insulating member 23 and the second insulating member 24 provided, during normal use, both the first insulating member 23 and the second insulating member 24 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of short circuit due to contact between the main body portion 221 and the first wall portion 213. Because the material damage temperature of the second insulating member 24 is higher than that of the first insulating member 23, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the second insulating member 24 can still, to a certain extent, insulate and isolate the main body 221 and the first wall 213, reducing the risk of a short circuit due to contact between the main body 221 and the first wall 213. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in that battery cell 20 and further trigger thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20.

[0379] The electrode assembly 22 includes a positive electrode 2212, a separator 2213, and a negative electrode 2214. The positive electrode 2212, separator 2213, and negative electrode 2214 are wound or stacked. A second insulating member 24 is connected to the separator 2213. By connecting the second insulating member 24 to the separator 2213, on the one hand, it helps to fix the separator 2213, maintain its shape, and reduce the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20. On the other hand, the second insulating member 24 can prevent heat from being transferred to the separator 2213 to a certain extent, thereby reducing the risk of the separator 2213 shrinking due to high temperature. This makes the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which helps to improve the reliability of the battery cell 20.

[0380] The second insulating member 24 includes a first insulating portion 241 and a second insulating portion 242 connected together. The first insulating portion 241 is at least partially disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213. Along a first direction, the main body portion 221 has two opposing first surfaces 2211, and the second insulating portion 242 is connected to one of the first surfaces 2211. The first direction is perpendicular to the thickness direction of the first wall portion 213. The first insulating portion 241 is at least partially disposed between the main body portion 221 and the first wall portion 213 along the thickness direction of the first wall portion 213. During normal use, both the first insulating member 23 and the first insulating portion 241 can insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. Because the material damage temperature of the second insulating member 24 is higher than that of the first insulating member 23, when another battery cell 20 adjacent to the battery cell 20 experiences thermal runaway, causing the first insulating member 23 of that battery cell 20 to melt, the first insulating portion 241 can still, to a certain extent, insulate and isolate the main body portion 221 and the first wall portion 213, reducing the risk of a short circuit due to contact between the main body portion 221 and the first wall portion 213. The second insulating portion 242 is connected to the first surface 2211. On the one hand, it restricts the relative positions of the first insulating portion 241 and the main body portion 221, and the second insulating portion 242 and the main body portion 221, to a certain extent, allowing the first insulating portion 241 to be stably positioned between the main body portion 221 and the first wall portion 213, thereby insulating and isolating the main body portion 221 and the first wall portion 213, which is beneficial to improving the reliability of the battery cell 20. On the other hand, the second insulating portion 242 can reduce the risk of a short circuit due to contact between the first surface 2211 and other components, which is beneficial to improving the reliability of the battery cell 20.

[0381] The outer casing 21 includes a second wall portion 2121, which is connected to the first wall portion 213. The second wall portion 2121 has the largest outer surface area among the outer casing 21. Along a first direction, a second insulating portion 242 is at least partially located between the main body portion 221 and the second wall portion 2121. The second insulating portion 242, located at least partially along the first direction between the main body portion 221 and the second wall portion 2121, insulates and isolates the main body portion 221 and the second wall portion 2121. Due to the high material damage temperature of the second insulating member 24, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, the second insulating portion 242 can still, to a certain extent, insulate and isolate the main body portion 221 and the second wall portion 2121, reducing the risk of a short circuit due to contact between the main body portion 221 and the second wall portion 2121. Thus, even if another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, it is less likely to cause a short circuit in this battery cell 20 and further trigger thermal runaway, which helps limit heat diffusion and improves the reliability of the battery cell 20. Furthermore, since the second wall portion 2121 has the largest outer surface area in the outer casing 21, when another battery cell 20 adjacent to this battery cell 20 experiences thermal runaway, heat can easily be transferred from the second wall portion 2121 to the main body portion 221, causing the insulating member 2213 of the main body portion 221 to shrink due to heat. The second insulating portion 242 can, to a certain extent, prevent heat transfer to the main body portion 221, thereby reducing the risk of the insulating member 2213 shrinking due to high temperature, making the positive electrode 2212 and negative electrode 2214 less likely to be exposed, which is beneficial to improving the reliability of the battery cell 20.

[0382] In some embodiments, each electrode assembly 22 is provided with at least one second insulating member 24. The second insulating member 24 includes two second insulating portions 242, with a first insulating portion 241 connecting the two second insulating portions 242. The two second insulating portions 242 are respectively connected to two first surfaces 2211 of the main body portion 221. The provision of at least one second insulating member 24 for each electrode assembly 22, and the connection of the two second insulating portions 242 of each second insulating member 24 to the two first surfaces 2211 of the main body portion 221, ensures that each electrode assembly 22 is well protected. Furthermore, during manufacturing, each second insulating member 24 can be individually connected to each electrode assembly 22, which helps reduce production difficulty.

[0383] In other embodiments, the battery cell 20 includes a plurality of electrode assemblies 22 stacked along a first direction. Two electrode assemblies 22 located at opposite ends of the first direction are respectively a first electrode assembly 223 and a second electrode assembly 224. The second insulating member 24 includes two second insulating portions 242. One second insulating portion 242 is connected to a first surface 2211 of the first electrode assembly 223 facing away from the second electrode assembly 224, and the other second insulating portion 242 is connected to a first surface 2211 of the second electrode assembly 224 facing away from the first electrode assembly 223. Along the thickness direction of the first wall portion 213, one second insulating member 24 is located between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22. One second insulating member 24 is sufficient to achieve insulation isolation between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22, providing good insulation performance. Furthermore, the presence of a second insulating member 24 between the main body portion 221 and the first wall portion 213 of the plurality of electrode assemblies 22 helps to reduce the space occupied inside the casing 21 and improve the energy density of the battery cell 20.

[0384] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. 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 outer casing has a first wall portion; An electrode assembly is housed within the housing. The electrode assembly includes a tab and a main body, with the tab disposed at one end of the main body. A first insulating member is at least partially disposed between the electrode assembly and the first wall portion, the first insulating member being used to insulate and isolate the electrode assembly and the first wall portion; A second insulating element is at least partially disposed between the main body portion and the first wall portion, and the material damage temperature of the second insulating element is greater than that of the first insulating element.

2. The battery cell according to claim 1, characterized in that, The second insulating element is connected to the main body.

3. The battery cell according to claim 2, characterized in that, The second insulating member is connected to the end of the main body facing the first wall portion.

4. The battery cell according to claim 2, characterized in that, The electrode assembly includes a positive electrode, an insulator, and a negative electrode, wherein the positive electrode, the insulator, and the negative electrode are wound or stacked, and the second insulating member is connected to the insulator.

5. The battery cell according to claim 4, characterized in that, The second insulating element is bonded to the insulating element.

6. The battery cell according to claim 1, characterized in that, The second insulating element includes a first insulating portion and a second insulating portion connected together; Along the thickness direction of the first wall portion, the first insulating portion is at least partially disposed between the main body portion and the first wall portion; Along a first direction, the main body has two opposing first surfaces, and the second insulating portion is connected to one of the first surfaces. The first direction is perpendicular to the thickness direction of the first wall portion.

7. The battery cell according to claim 6, characterized in that, The outer shell includes a second wall portion, which is connected to the first wall portion, and the second wall portion is the wall portion with the largest outer surface area in the outer shell. Along the first direction, the second insulating portion is at least partially located between the main body portion and the second wall portion.

8. The battery cell according to claim 6, characterized in that, Each electrode assembly is provided with at least one second insulating member, the second insulating member including two second insulating portions, the first insulating portion connecting the two second insulating portions, and the two second insulating portions respectively connecting to the two first surfaces of the main body portion.

9. The battery cell according to claim 8, characterized in that, The battery cell includes a plurality of electrode assemblies stacked along the first direction. Along the first direction, in two adjacent second insulating members, a second insulating portion of one second insulating member is connected to a second insulating portion of the other second insulating member.

10. The battery cell according to claim 6, characterized in that, The battery cell includes a plurality of electrode components stacked along the first direction, wherein the two electrode components located at both ends of the first direction are the first electrode component and the second electrode component, respectively. The second insulating member includes two second insulating portions, one second insulating portion connected to a first surface of the first electrode assembly opposite to the second electrode assembly, and the other second insulating portion connected to the second electrode assembly opposite to the first surface of the first electrode assembly.

11. The battery cell according to claim 6, characterized in that, Both the first insulating part and the second insulating part are connected to the main body part.

12. The battery cell according to claim 6, characterized in that, The main body includes a first end facing the first wall portion, and the first insulating portion and the electrode tab are both disposed on the first end, and the first insulating portion and the electrode tab are arranged along the first direction.

13. The battery cell according to claim 12, characterized in that, The battery cell includes a plurality of electrode assemblies stacked along the first direction, and each electrode assembly is provided with at least one second insulating member. The plurality of electrode assemblies include adjacent first electrode assemblies and second electrode assemblies, wherein the second insulating portion of the second insulating member disposed on the first electrode assembly is connected to the first surface of the first electrode assembly facing the second electrode assembly, and the second insulating portion of the second insulating member disposed on the second electrode assembly is connected to the first surface of the second electrode assembly facing the first electrode assembly.

14. The battery cell according to claim 13, characterized in that, The second insulating portion of the second insulating member disposed on the first electrode assembly is connected to the second insulating portion of the second insulating member disposed on the second electrode assembly.

15. The battery cell according to claim 13, characterized in that, The second insulating member includes a third insulating portion that extends from the first insulating portion in a direction close to the first wall portion and is connected to the side of the tab facing the first insulating portion.

16. The battery cell according to claim 6, characterized in that, The electrode assembly includes a positive electrode, an insulator, and a negative electrode, wherein the positive electrode, the insulator, and the negative electrode are wound or stacked. The first surface is the surface of the insulating member.

17. The battery cell according to claim 6, characterized in that, Along the thickness direction of the first wall portion, the first insulating member is at least partially located on the side of the first insulating portion away from the electrode assembly.

18. The battery cell according to claim 17, characterized in that, The outer casing includes a housing and an end cap, the housing having an opening, the end cap closing the opening, and the end cap being the first wall portion; The first insulating element is a lower plastic component disposed on the side of the end cap facing the electrode assembly.

19. The battery cell according to claim 17, characterized in that, The outer casing includes a housing and an end cap. The housing includes a side wall and a bottom wall. The side wall surrounds the bottom wall, and one end of the side wall opposite to the bottom wall forms an opening. The end cap closes the opening. The sidewall includes the first wall portion or the bottom wall is the first wall portion.

20. The battery cell according to claim 19, characterized in that, The first insulating element is an insulating film covering the electrode assembly.

21. The battery cell according to claim 6, characterized in that, Along the thickness direction of the first wall portion, the first insulating member is at least partially located on the side of the first insulating portion facing the electrode assembly.

22. The battery cell according to claim 21, characterized in that, The outer casing includes a housing and an end cap, the housing having an opening, the end cap closing the opening, and the wall portion of the housing opposite to the end cap being the first wall portion; The first insulating component is a base plate that supports the electrode assembly.

23. The battery cell according to claim 6, characterized in that, Along the thickness direction of the first wall portion, the dimension of the second insulating portion is L, which satisfies: 3mm≤L≤50mm.

24. The battery cell according to claim 23, characterized in that, 8mm≤L≤15mm.

25. The battery cell according to claim 1, characterized in that, The second insulating element has a flat plate structure.

26. The battery cell according to claim 1, characterized in that, Each of the electrode assemblies is provided with at least one of the second insulating elements.

27. The battery cell according to claim 1, characterized in that, Each of the second insulating elements is located between the body portion of the plurality of electrode assemblies and the first wall portion.

28. The battery cell according to claim 1, characterized in that, Along the thickness direction of the first wall portion, the main body portion has a first end facing the first wall portion; The electrode assembly includes two tabs with opposite polarities, and both tabs are disposed at the first end; The first insulating member is at least partially disposed between the first end and the first wall portion, and the second insulating member is at least partially disposed between the first end and the first wall portion.

29. The battery cell according to claim 28, characterized in that, The two electrodes are spaced apart at the first end along the second direction; Along the second direction, a second insulating element is disposed between the two electrodes; and / or Along the second direction, the second insulating element is provided on the side of one of the electrodes opposite to the other electrode.

30. The battery cell according to claim 1, characterized in that, The main body has a first end and a second end disposed opposite to each other, with the first end facing the first wall portion; The electrode assembly includes two tabs with opposite polarities, and both tabs are disposed at the second end; The first insulating member is at least partially disposed between the first end and the first wall portion, and the second insulating member is at least partially disposed between the first end and the first wall portion.

31. The battery cell according to claim 1, characterized in that, The outer casing includes two first wall portions disposed opposite to each other, and a first insulating member and a second insulating member are disposed between each first wall portion and the main body portion.

32. The battery cell according to claim 1, characterized in that, The second insulating element is connected to the first insulating element.

33. The battery cell according to claim 32, characterized in that, The first insulating member is an insulating film covering the electrode assembly, and the second insulating member is connected to the side of the first insulating member facing the main body.

34. The battery cell according to claim 32, characterized in that, The first insulating member is a base plate that supports the electrode assembly, and the second insulating member is connected to the side of the first insulating member facing the first wall.

35. The battery cell according to claim 1, characterized in that, The first wall portion is the wall portion with the largest outer surface area in the outer shell.

36. The battery cell according to claim 1, characterized in that, The first wall portion is provided with a pressure relief mechanism, which has a first pressure relief area. The first pressure relief area is used to open when the battery cell is depressurized. The second insulating member is provided with a through hole at a position corresponding to the first pressure relief area.

37. The battery cell according to claim 1, characterized in that, The first wall portion is provided with a pressure relief mechanism, which has a first pressure relief area. The second insulating member is provided with a second pressure relief area at a position corresponding to the first pressure relief area. The first pressure relief area and the second pressure relief area are used to open when the battery cell is depressurized.

38. The battery cell according to claim 37, characterized in that, The second insulating member has a weak structure and is configured to crack along the weak structure when a battery cell is depressurized, thereby opening the second depressurization area.

39. The battery cell according to claim 38, characterized in that, The weak structure includes an annular groove disposed in the second insulating member.

40. The battery cell according to claim 38, characterized in that, The weak structure includes a plurality of grooves or through holes spaced circumferentially along the second pressure relief region.

41. The battery cell according to claim 38, characterized in that, The area of ​​the second pressure relief region is smaller than the area of ​​the first pressure relief region.

42. The battery cell according to any one of claims 1-41, characterized in that, The second insulating component is an insulating film.

43. The battery cell according to claim 42, characterized in that, The thickness of the insulating film is H, which satisfies: 0.01mm≤H≤0.5mm.

44. The battery cell according to claim 43, characterized in that, 0.05mm≤H≤0.2mm.

45. The battery cell according to any one of claims 1-41, characterized in that, The material damage temperature of the second insulating component is greater than or equal to 150°C.

46. ​​The battery cell according to claim 45, characterized in that, The material damage temperature of the second insulating component is greater than or equal to 250°C.

47. The battery cell according to any one of claims 1-41, characterized in that, The material of the second insulating element includes at least one of polyethylene terephthalate, polyphthalamide, polyphenylene sulfide, and polyimide.

48. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-47.

49. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-47, the battery cell being used to provide electrical energy to the electrical device.

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