Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. The battery monomer comprises a shell, an electrode assembly, a first electrode terminal, a first insulating part and a protective layer, the electrode assembly is contained in the shell and electrically connected with the first electrode terminal, the first electrode terminal comprises a leading-out piece, the leading-out piece is used for being connected with the confluence component in a welded mode, and a first connecting part is formed on the leading-out piece. The first insulating part is arranged between the leading-out part and the wall part in the thickness direction of the wall part, and in a projection plane perpendicular to the thickness direction of the wall part, the orthographic projection of the first insulating part is at least partially overlapped with the orthographic projection of the first connecting part. The protective layer is arranged between the lead-out piece and the first insulating piece, the melting point of the protective layer is larger than that of the lead-out piece, and in a projection plane perpendicular to the thickness direction of the wall part, at least part of the orthographic projection of the first connecting part is located in the orthographic projection of the protective layer, so that the risk that the first insulating piece is melted after the lead-out piece is welded through is reduced.

Description

TECHNICAL FIELD

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

[0002] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. The battery device, as a core component of new energy vehicles, has high requirements in terms of use performance.

[0003] In the battery technology, the battery monomer of the battery device usually includes a shell and an electrode assembly contained in the shell, and an electrode terminal is arranged on the shell. The electrode terminal is electrically connected with the electrode assembly to realize the input or output of the electric energy of the battery monomer. However, the electrode terminal of the existing battery monomer is prone to short circuit with the shell, which is not conducive to improving the use reliability of the battery monomer. UTILITY MODEL CONTENT

[0004] The present application provides a battery monomer, a battery device and a power utilization device, which can effectively improve the use reliability of the battery monomer.

[0005] In a first aspect, the present application provides a battery monomer, which includes a shell, an electrode assembly, a first electrode terminal, a first insulating member and a protective layer. The shell has a wall portion. The electrode assembly is contained in the shell. The first electrode terminal is electrically connected with the electrode assembly. The first electrode terminal includes a lead-out member located on a side of the wall portion away from the electrode assembly. The lead-out member is used to be welded with a bus member and form a first connecting portion on the lead-out member. At least part of the first insulating member is arranged between the lead-out member and the wall portion in the thickness direction of the wall portion. In a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first insulating member at least partially overlaps the orthographic projection of the first connecting portion. At least part of the protective layer is arranged between the lead-out member and the first insulating member. The melting point of the protective layer is greater than the melting point of the lead-out member. In the projection plane perpendicular to the thickness direction of the wall portion, at least part of the orthographic projection of the first connecting portion is located in the orthographic projection of the protective layer.

[0006] In the technical scheme, the first electrode terminal is electrically connected with the electrode assembly, and the first electrode terminal is arranged on the lead-out piece on the side of the wall part away from the electrode assembly and is used for being welded with the busbar component to realize input or output of the electric energy of the battery monomer through the first electrode terminal, a first insulating piece is arranged between the lead-out piece and the wall part, so that the first insulating piece can insulate and separate the lead-out piece and the wall part, at least part of the projection of the first connecting part on the thickness direction of the wall part overlaps with the projection of the first connecting part on the thickness direction of the wall part, a protective layer is arranged between the lead-out piece and the wall part, the melting point of the protective layer is greater than the melting point of the lead-out piece, at least part of the projection of the first connecting part on the thickness direction of the wall part is located in the protective layer, and the protective layer can protect and separate the first insulating piece when the lead-out piece is welded with the busbar component, so as to reduce the phenomenon that the first insulating piece is burned or melted after the lead-out piece is welded through, thereby reducing the risk of the lead-out piece being welded through by increasing the thickness of the lead-out piece, so that the thickness of the lead-out piece can be optimized while the risk of insulation failure between the lead-out piece and the wall part after the first insulating piece is damaged can be effectively reduced, and the short circuit risk of the first electrode terminal and the shell in use can be reduced, thereby improving the use reliability of the battery monomer.

[0007] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall part, the orthographic projection of the first connecting part is entirely located in the orthographic projection of the protective layer.

[0008] In the technical scheme, the projection of the first connecting part on the thickness direction of the wall part is arranged in the structure that the whole is located in the protective layer, so that the protective layer can effectively separate the first connecting wall and the first insulating piece in the thickness direction of the wall part, thereby further reducing the phenomenon that the first insulating piece is burned or melted after the lead-out piece is welded through, further reducing the risk of insulation failure between the lead-out piece and the wall part after the first insulating piece is damaged, further reducing the short circuit risk of the first electrode terminal and the shell in use, and further improving the use reliability of the battery monomer.

[0009] In some embodiments, the melting point of the protective layer is T1, and the melting point of the lead-out piece is T2, and T1-T2 is greater than or equal to 200 DEG C.

[0010] In the technical scheme, the melting point of the protective layer is greater than or equal to 200 DEG C than the melting point of the lead-out piece, so as to further alleviate the phenomenon that the protective layer is melted when the lead-out piece is welded with the busbar component, thereby further improving the separation effect and the blocking effect of the protective layer, and further improving the protection effect of the first insulating piece when the lead-out piece is welded with the busbar component.

[0011] In some embodiments, the melting point of the protective layer is T1, satisfying 1000℃≤T1≤3000℃.

[0012] In the above technical solution, on the one hand, the melting point of the protective layer is set to be greater than or equal to 1000 degrees Celsius, so that the protective layer has good high-temperature resistance effect, thereby the protective layer can play a good separating and protecting effect on the first insulating part when the lead-out piece is welded to the busbar component, so as to reduce the risk of burning or melting the first insulating part after the lead-out piece is welded through, on the other hand, the melting point of the protective layer is set to be less than or equal to 3000 degrees Celsius, so as to alleviate the phenomenon of excessive high-temperature resistance of the protective layer, thereby the difficulty of material selection and manufacturing of the protective layer can be reduced, and the manufacturing cost of the protective layer can be reduced.

[0013] In some embodiments, the lead-out piece and the protective layer are stacked along the thickness direction of the wall part; wherein, in the projection plane perpendicular to the thickness direction of the wall part, the orthographic projection of the lead-out piece is located in the orthographic projection of the protective layer.

[0014] In the above technical solution, by setting the lead-out piece and the protective layer to be stacked along the thickness direction of the wall part, and the projection of the lead-out piece in the thickness direction of the wall part is located in the protective layer, the protective layer can effectively separate the lead-out piece and the first insulating part in the thickness direction of the wall part, so as to further improve the protection effect of the protective layer on the first insulating part when the lead-out piece is welded to the busbar component, thereby the risk of burning or melting the first insulating part after the lead-out piece is welded through can be further reduced.

[0015] In some embodiments, the maximum size of the protective layer and the lead-out piece in the thickness direction of the wall part is D1, satisfying D1<3mm.

[0016] In the above technical solution, since the separation effect of the protective layer can realize the reduction of the risk of the lead-out piece being welded through without increasing the thickness of the lead-out piece, the thickness of the lead-out piece in the thickness direction of the wall part can be optimized, so as to make the thickness of the lead-out piece in the thickness direction of the wall part small, and then the maximum size of the protective layer and the lead-out piece in the thickness direction of the wall part is set to be less than 3mm, so as to save the space occupied by the first electrode terminal and the protective layer in the thickness direction of the wall part, so as to optimize the overall size of the battery monomer, which is beneficial to improve the energy density of the battery monomer.

[0017] In some embodiments, 1.8mm≤D1≤2.8mm.

[0018] In the above technical solution, on the one hand, the maximum dimension of the protective layer and the lead-out piece in the thickness direction of the wall part is greater than or equal to 1.8 mm, which can facilitate the setting of a relatively thick protective layer and lead-out piece, is beneficial to improve the separation effect and protection effect of the protective layer on the first insulating piece when the lead-out piece is welded and connected with the busbar component, and is beneficial to improve the structural strength of the lead-out piece, so as to reduce the risk of fracture or deformation of the lead-out piece in the use process. On the other hand, the maximum dimension of the protective layer and the lead-out piece in the thickness direction of the wall part is less than or equal to 2.8 mm, which can further save the space occupied by the lead-out piece and the protective layer in the thickness direction of the wall part, so as to further optimize the overall size of the battery monomer, and is beneficial to further improve the energy density of the battery monomer.

[0019] In some embodiments, along the thickness direction of the wall part, the thickness of the protective layer is D2, and the thickness of the lead-out piece is D3, satisfying 0.1≤D2 / D3≤0.25.

[0020] In the above technical solution, on the one hand, the thickness of the protective layer is greater than or equal to 0.1 times the thickness of the lead-out piece, so that the protective layer has sufficient thickness to separate and block when the lead-out piece is welded and connected with the busbar component, so as to alleviate the phenomenon that the protective layer is welded through, which is beneficial to improve the separation effect and protection effect of the protective layer on the first insulating piece when the lead-out piece is welded and connected with the busbar component. On the other hand, the thickness of the protective layer is less than or equal to 0.25 times the thickness of the lead-out piece, so as to reduce the waste phenomenon caused by the excessive thickness of the protective layer, which is beneficial to reduce the manufacturing cost of the battery monomer, and can save the space occupied by the protective layer in the thickness direction of the wall part, which is beneficial to optimize the overall size of the battery monomer.

[0021] In some embodiments, 0.3mm≤D2≤1mm.

[0022] In the above technical solution, on the one hand, the thickness of the protective layer in the thickness direction of the wall part is greater than or equal to 0.3 mm, which is beneficial to improve the structural strength of the protective layer, and makes the protective layer have sufficient thickness to separate and block when the lead-out piece is welded and connected with the busbar component, so as to alleviate the phenomenon that the protective layer is welded through, which is beneficial to improve the separation effect and protection effect of the protective layer on the first insulating piece when the lead-out piece is welded and connected with the busbar component. On the other hand, the thickness of the protective layer in the thickness direction of the wall part is less than or equal to 1 mm, so as to reduce the waste phenomenon caused by the excessive thickness of the protective layer, which is beneficial to reduce the manufacturing cost of the battery monomer, and can save the space occupied by the protective layer in the thickness direction of the wall part, which is beneficial to optimize the overall size of the battery monomer.

[0023] In some embodiments, 1mm≤D3≤2.5mm.

[0024] In the technical solution, the thickness dimension of the lead-out piece in the thickness direction of the wall portion is greater than or equal to 1 mm, which is beneficial to improve the structural strength of the lead-out piece, reduce the risk of deformation or fracture of the lead-out piece in use, and enable the lead-out piece to have sufficient penetration when being welded with the busbar component, thereby improving the connection reliability and stability between the lead-out piece and the busbar component. On the other hand, the thickness dimension of the lead-out piece in the thickness direction of the wall portion is less than or equal to 2.5 mm, which saves the space occupied by the lead-out piece in the thickness direction of the wall portion, thereby optimizing the overall size of the battery monomer and improving the energy density of the battery monomer.

[0025] In some embodiments, along the thickness direction of the wall portion, the lead-out piece has a first surface facing the wall portion, and the first surface is provided with a recess, and at least part of the protective layer is accommodated in the recess.

[0026] In the technical solution, the recess is arranged on the first surface of the lead-out piece facing the wall portion, and at least part of the protective layer is accommodated in the recess along the thickness direction of the wall portion, so that the protective layer plays a separating role between the lead-out piece and the first insulating piece while the protective layer and the lead-out piece share part of the space in the thickness direction of the wall portion, which is beneficial to optimize the space occupied by the protective layer and the lead-out piece in the thickness direction of the wall portion, thereby optimizing the overall size of the battery monomer and improving the energy density of the battery monomer.

[0027] In some embodiments, along the thickness direction of the wall portion, the protective layer has a second surface facing the wall portion, and the second surface and the first surface are coplanar.

[0028] In the technical solution, the second surface of the protective layer facing the wall portion and the first surface of the lead-out piece facing the wall portion are arranged to be coplanar, so that the protective layer is accommodated in the recess of the lead-out piece. On the one hand, this structure can further optimize the space occupied by the protective layer and the lead-out piece in the thickness direction of the wall portion, thereby further optimizing the overall size of the battery monomer and further improving the energy density of the battery monomer. On the other hand, the recess can stabilize and protect the protective layer, thereby reducing the wear of the protective layer in use.

[0029] In some embodiments, along the thickness direction of the wall portion, the protective layer has a third surface away from the wall portion; wherein one of the surface of the lead-out piece facing the wall portion and the third surface is provided with a first limiting protrusion, and the other is provided with a first limiting groove, and the first limiting protrusion and the first limiting groove are inserted and matched.

[0030] In the technical scheme, the first limiting protrusion is arranged on one of the surface of the lead-out piece facing the wall portion and the third surface of the protective layer facing away from the wall portion, and the first limiting groove is arranged on the other one, so that the lead-out piece and the protective layer are limited and positioned, the assembly precision between the lead-out piece and the protective layer is improved, the assembly stability between the lead-out piece and the protective layer is improved, and the risk that the protective layer shakes or moves during use is reduced.

[0031] In some embodiments, the surface of the lead-out piece facing the wall portion is provided with the first limiting groove, and the third surface is provided with the first limiting protrusion.

[0032] In the technical scheme, the first limiting groove is arranged on the lead-out piece, and the first limiting protrusion is arranged on the protective layer, so that the lead-out piece and the protective layer are limited and positioned, and the area of the protective layer corresponding to the lead-out piece is not grooved, so that the influence of the first limiting groove on the structural strength of the protective layer or the effect of separating the lead-out piece is reduced.

[0033] In some embodiments, one of the surface of the lead-out piece facing the wall portion and the third surface is provided with a plurality of first limiting protrusions, and the other one is provided with a plurality of first limiting grooves, and each first limiting protrusion is inserted into the first limiting groove.

[0034] In the technical scheme, a plurality of first limiting protrusions are arranged on one of the surface of the lead-out piece facing the wall portion and the third surface of the protective layer facing away from the wall portion, and a plurality of first limiting grooves are correspondingly arranged on the other one, and each first limiting protrusion is matched with a first limiting groove, so that the limiting effect between the lead-out piece and the protective layer is further improved, the assembly stability between the lead-out piece and the protective layer is further improved, and the risk that the protective layer shakes or moves during use is further reduced.

[0035] In some embodiments, the first insulating piece includes an insulating body and a flange portion; the insulating body is arranged between the protective layer and the wall portion along the thickness direction of the wall portion; the flange portion surrounds the outside of the lead-out piece, and the flange portion is connected to the insulating body at one end of the wall portion in the thickness direction of the wall portion.

[0036] In the technical solution, the first insulating piece is provided with an insulating body between the protective layer and the wall portion and a flange portion surrounding the lead-out piece, and one end of the flange portion in the thickness direction of the wall portion is connected to the insulating body, so that the insulating body and the flange portion jointly form a groove structure for accommodating the lead-out piece and the protective layer. On the one hand, the insulating isolation effect of the first insulating piece between the lead-out piece and the wall portion can be further improved, so as to further reduce the risk of short circuit of the lead-out piece and the wall portion. On the other hand, the assembly stability between the first insulating piece and the lead-out piece can be improved, and the assembly reliability of the protective layer arranged between the lead-out piece and the first insulating piece can be improved.

[0037] In some embodiments, along the thickness direction of the wall portion, the insulating body has a fourth surface facing away from the wall portion, and the flange portion is protruded on the fourth surface; wherein the fourth surface is provided with an accommodation groove, and at least part of the protective layer is accommodated in the accommodation groove.

[0038] In the technical solution, the accommodation groove is arranged on the fourth surface of the insulating body facing the lead-out piece, and at least part of the protective layer is accommodated in the accommodation groove, so that the protective layer and the insulating body of the first insulating piece can share part of the space in the thickness direction of the wall portion. This is beneficial to optimize the space occupied by the protective layer and the insulating body in the thickness direction of the wall portion, so as to optimize the overall size of the battery monomer, and improve the energy density of the battery monomer.

[0039] In some embodiments, a second limiting protrusion is protruded on the outer circumferential surface of the protective layer, a second limiting groove is arranged on the groove side surface of the accommodation groove, and the second limiting protrusion is inserted into the second limiting groove.

[0040] In the technical solution, the second limiting protrusion is protruded on the outer circumferential surface of the protective layer, and the second limiting groove corresponding to the second limiting protrusion is arranged on the groove side surface of the accommodation groove. This realizes the limiting and positioning between the protective layer and the insulating body of the first insulating piece. On the one hand, the assembly precision of the protective layer arranged in the accommodation groove can be improved, so as to improve the assembly quality of the protective layer arranged between the lead-out piece and the first insulating piece. On the other hand, the circumferential locking between the protective layer and the insulating body can be realized, so as to reduce the phenomenon that the protective layer rotates circumferentially relative to the insulating body of the first insulating piece.

[0041] In some embodiments, a plurality of second limiting protrusions are protruded on the outer circumferential surface of the protective layer, and the plurality of second limiting protrusions are arranged at intervals along the circumference of the protective layer. A plurality of second limiting grooves are arranged on the groove side surface of the accommodation groove, and each second limiting protrusion is inserted into a second limiting groove.

[0042] In the technical scheme, the second limiting protrusions are arranged on the outer circumferential surface of the protection layer, and the second limiting grooves corresponding to the second limiting protrusions are arranged on the groove side surface of the accommodating groove, so that the limiting effect and the positioning effect between the protection layer and the insulating main body of the first insulating piece are further improved, the assembly precision of the protection layer arranged in the accommodating groove is further improved, the assembly quality of the protection layer arranged between the lead-out piece and the first insulating piece is further improved, and the phenomenon that the protection layer rotates relative to the insulating main body of the first insulating piece is further reduced.

[0043] In some embodiments, the second limiting groove penetrates the fourth surface along the thickness direction of the wall portion.

[0044] In the technical scheme, the second limiting groove is arranged in a structure penetrating the fourth surface, so that the second limiting groove is arranged in a structure penetrating the fourth surface and the groove side surface of the accommodating groove, the difficulty of arranging the second limiting groove on the groove side surface of the accommodating groove is reduced, and the manufacturing difficulty of the first insulating piece is reduced.

[0045] In some embodiments, a surface of the wall portion away from the electrode assembly is provided with an assembly groove along the thickness direction of the wall portion, and at least part of the first insulating piece is arranged in the assembly groove.

[0046] In the technical scheme, the assembly groove is arranged on the surface of the wall portion away from the electrode assembly, and at least part of the first insulating piece is arranged in the assembly groove. The battery monomer with the structure has the following advantages. On the one hand, the assembly groove can limit and position the first insulating piece, which is beneficial to reducing the difficulty of assembling the first insulating piece between the wall portion and the lead-out piece, and reducing the phenomenon that the first insulating piece shakes or shifts during use, thereby improving the assembly stability of the first insulating piece. On the other hand, the first insulating piece and the wall portion share part of the space in the thickness direction of the wall portion, which is beneficial to optimizing the overall size of the battery monomer.

[0047] In some embodiments, the wall portion is provided with an electrode lead-out hole penetrating the wall portion along the thickness direction of the wall portion; and the first electrode terminal further comprises a connecting piece connected with the lead-out piece, the connecting piece is arranged in the electrode lead-out hole and electrically connected with the electrode assembly.

[0048] In the technical scheme, the wall portion is provided with the electrode lead-out hole penetrating the wall portion along the thickness direction of the wall portion, and the first electrode terminal is further provided with the connecting piece connected with the lead-out piece. After the connecting piece is arranged in the electrode lead-out hole, the connecting piece can be electrically connected with the electrode assembly in the shell, so that the input or output of the electric energy of the battery monomer is realized through the first electrode terminal. The structure is simple and convenient to assemble.

[0049] In some embodiments, the connecting piece comprises a body portion and a limiting portion; the body portion is arranged in the electrode lead-out hole along the thickness direction of the wall portion, and the body portion is connected with the lead-out piece; the limiting portion is protruded on the outer circumferential surface of the body portion; wherein, along the thickness direction of the wall portion, the limiting portion is located on the side of the wall portion facing away from the electrode assembly, and at least part of the wall portion is located between the limiting portion and the lead-out piece.

[0050] In the above technical solution, the connecting piece of the first electrode terminal is provided with a body portion and a limiting portion protruded on the outer circumferential surface of the body portion, the body portion is connected with the lead-out piece, and the limiting portion is located on the side of the wall portion facing away from the lead-out piece, so that at least part of the wall portion is located between the limiting portion and the lead-out piece, so that the limiting portion and the lead-out piece can cooperate to clamp the wall portion, thereby realizing the assembly of the first electrode terminal to the wall portion, which is simple in structure, convenient to assemble, and can improve the structural stability of the first electrode terminal assembled to the wall portion.

[0051] In some embodiments, the battery monomer further comprises a second insulating piece, at least part of the second insulating piece is arranged between the limiting portion and the wall portion along the thickness direction of the wall portion, so as to insulate and isolate the limiting portion and the wall portion.

[0052] In the above technical solution, the second insulating piece is further arranged between the limiting portion and the wall portion, so that the second insulating piece can play a certain insulating and isolating role on the limiting portion and the wall portion, thereby reducing the risk of short circuit between the limiting portion and the wall portion, and reducing the phenomenon of short circuit of the battery monomer during use.

[0053] In some embodiments, the body portion and the lead-out piece are riveted.

[0054] In the above technical solution, by setting the body portion and the lead-out piece of the connecting piece as riveted to each other, the connection stability between the connecting piece and the lead-out piece is improved, the risk of connection failure of the first electrode terminal during use is reduced, and the connection difficulty between the connecting piece and the lead-out piece is reduced, thereby improving the assembly efficiency of the battery monomer.

[0055] In some embodiments, the battery monomer further comprises a sealing piece; the sealing piece is arranged between the connecting piece and the wall portion, and the sealing piece is configured to seal the gap between the connecting piece and the hole wall surface of the electrode lead-out hole.

[0056] In the above technical solution, the battery monomer is further provided with a sealing piece, by arranging the sealing piece between the wall portion and the connecting piece of the first electrode terminal, the sealing piece can seal the gap between the connecting piece and the hole wall surface of the electrode lead-out hole, thereby reducing the risk of leakage of the battery monomer at the electrode lead-out hole, and improving the use stability and reliability of the battery monomer.

[0057] In some embodiments, the material of the lead-out piece comprises aluminum, and the material of the protective layer comprises steel, copper, ceramic or mica.

[0058] In the above technical solution, the material of the lead-out piece comprises aluminum, so that the lead-out piece has good electrical conductivity, and because the melting point of aluminum is low, the lead-out piece is convenient to be welded and connected with the busbar component, which is conducive to reducing the assembly difficulty between the lead-out piece and the busbar component. The material of the protective layer comprises steel, copper, ceramic or mica, and the protective layer made of these materials has a high melting point, so that the protective layer is not easy to be welded through or melted through when the lead-out piece is welded and connected with the busbar component, thereby improving the separation effect and protection effect of the protective layer on the wall portion or other components.

[0059] In some embodiments, the first electrode terminal is a positive electrode of the battery monomer.

[0060] In the above technical solution, by setting the first electrode terminal as the positive electrode of the battery monomer, the first electrode terminal can input or output the electrical energy of the battery monomer as the positive output pole of the battery monomer.

[0061] In some embodiments, the shell comprises a shell body and an end cover; an accommodating cavity with an opening is formed in the interior of the shell body, and the electrode assembly is accommodated in the accommodating cavity; the end cover closes the opening; wherein the end cover is the wall portion.

[0062] In the above technical solution, by setting the wall portion of the shell as the end cover used for closing the opening of the shell body, the battery monomer with this structure is convenient to assemble the first electrode terminal on the end cover and convenient to assemble and connect the first electrode terminal and the electrode assembly with each other, and it is convenient to set the protective layer between the lead-out piece and the first insulating piece, thereby being conducive to reducing the assembly difficulty of the battery monomer to improve the production efficiency of the battery monomer.

[0063] In some embodiments, the shell comprises a shell body and an end cover; the shell body comprises an integrally formed side wall and a bottom wall, the side wall is surrounded around the bottom wall, along the thickness direction of the wall portion, one end of the side wall is connected to the bottom wall, and the other end of the side wall is surrounded to form an opening, the side wall and the bottom wall jointly define an accommodating cavity, and the electrode assembly is accommodated in the accommodating cavity; the end cover closes the opening; wherein the bottom wall is the wall portion.

[0064] In the technical solution, the wall part of the shell is arranged as one wall opposite to the end cover in the thickness direction of the wall part. The battery cell with the structure can make the region where the first electrode terminal is mounted on the shell away from the end cover, and make the wall part not directly connected with the end cover, so as to relieve the phenomenon that the force generated when the first electrode terminal and other components pull or twist the wall part acts on the end cover, thereby reducing the risk of connection failure between the end cover and the shell, and further reducing the risk of liquid leakage of the battery cell in use.

[0065] In a second aspect, the embodiments of the present application also provide a battery device, comprising a current collecting component and the battery cell described above; the current collecting component is arranged on the side of the lead-out piece away from the protective layer in the thickness direction of the wall part, and the current collecting component is welded with the lead-out piece to form a connecting part, the connecting part comprises a first connecting part and a second connecting part connected with each other, the first connecting part is embedded in the lead-out piece, and the second connecting part is embedded in the current collecting component.

[0066] In the technical solution, the current collecting component is welded with the lead-out piece of the first electrode terminal to form a first connecting part on the lead-out piece and a second connecting part on the current collecting component, and the first connecting part and the second connecting part are connected with each other to realize the assembly connection between the first electrode terminal and the current collecting component. The battery device with the structure can improve the connection stability and reliability between the first electrode terminal and the current collecting component, and is conducive to improving the overcurrent effect between the first electrode terminal and the current collecting component.

[0067] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall part, the minimum distance between the outer edge of the front projection of the first connecting part and the front projection of the protective layer is L1, which satisfies 1mm≤L1≤2.5mm.

[0068] In the technical solution, on the one hand, the minimum distance between the front projection of the first connecting part in the protective layer along the thickness direction of the wall part and the outer edge of the protective layer is greater than or equal to 1mm, so as to improve the separation effect of the protective layer on the region where the lead-out piece forms a welding mark, thereby further improving the protection effect of the protective layer on the first insulating piece, and further reducing the risk that the lead-out piece is welded through and affects the first insulating piece. On the other hand, the minimum distance between the front projection of the first connecting part in the protective layer along the thickness direction of the wall part and the outer edge of the protective layer is less than or equal to 2.5mm, so as to relieve the phenomenon that the region of the lead-out piece for mutual welding with the current collecting component is limited due to too large distance, thereby increasing the size of the connecting part formed by mutual welding of the lead-out piece and the current collecting component, and further improving the connection stability and overcurrent effect between the lead-out piece and the current collecting component.

[0069] In some embodiments, a minimum distance between an outer edge of the front projection of the first connecting portion and the front projection of the lead-out piece in a projection plane perpendicular to a thickness direction of the wall portion is L2, satisfying 1mm≤L2≤2.5mm.

[0070] In the above technical solution, on one hand, the minimum distance between the outer edge of the front projection of the first connecting portion in the projection plane perpendicular to the thickness direction of the wall portion and the front projection of the lead-out piece is set to be greater than or equal to 1mm, so as to increase the distance between the area of the lead-out piece forming a welding mark and the outer edge of the lead-out piece, thereby facilitating the reduction of the phenomenon of melting of the outer edge of the lead-out piece, so as to improve the welding quality between the lead-out piece and the busbar component; on the other hand, the minimum distance between the outer edge of the front projection of the first connecting portion in the projection plane perpendicular to the thickness direction of the wall portion and the front projection of the lead-out piece is set to be less than or equal to 2.5mm, so as to alleviate the phenomenon that the area of the lead-out piece for mutual welding with the busbar component is limited due to the excessively large distance, thereby increasing the size of the connecting portion formed by mutual welding of the lead-out piece and the busbar component, so as to further improve the connection stability and overcurrent effect between the lead-out piece and the busbar component.

[0071] In some embodiments, along the thickness direction of the wall portion, the thickness of the area of the busbar component and the lead-out piece welded and connected is D4, satisfying 1.2mm≤D4≤3mm.

[0072] In the above technical solution, by setting the thickness of the area of the busbar component and the lead-out piece for mutual welding to be 1.2mm to 3mm, on one hand, the thickness of the area of the busbar component and the lead-out piece for mutual welding is set to be greater than or equal to 1.2mm, so as to improve the overcurrent performance of the busbar component, thereby improving the conductive effect of the busbar component, and at the same time, the welding power and the welding molten pool between the busbar component and the lead-out piece are increased, so that the protective layer arranged on the side of the lead-out piece facing the wall portion can effectively separate the area of the lead-out piece welded and melted, thereby reducing the risk of affecting other components after the lead-out piece is welded and melted; on the other hand, the thickness of the area of the busbar component and the lead-out piece for mutual welding is set to be less than or equal to 3mm, so as to reduce the phenomenon of excessive waste of the busbar component or excessively large welding power required, thereby reducing the welding difficulty between the busbar component and the lead-out piece, and reducing the manufacturing cost of the busbar component.

[0073] In some embodiments, the lead-out piece is provided with a first limiting groove on a surface of the lead-out piece facing the wall portion in the thickness direction of the wall portion, the protective layer has a third surface facing away from the wall portion, the third surface is provided with a first limiting protrusion, and the first limiting protrusion is inserted into the first limiting groove; wherein the first limiting groove is formed with a notch on the surface of the lead-out piece facing the wall portion, and a projection of the first connecting portion in a projection plane perpendicular to the thickness direction of the wall portion is located outside a projection of the notch.

[0074] In the above technical solution, the first limiting groove is arranged on the surface of the lead-out piece facing the wall portion, and the first limiting protrusion corresponding to the first limiting groove is arranged on the third surface of the protective layer facing away from the wall portion, so as to realize the limiting and positioning between the protective layer and the lead-out piece, thereby improving the assembly precision and stability between the protective layer and the lead-out piece. In addition, by arranging the projection of the first connecting portion of the connecting portion in the thickness direction of the wall portion outside the notch of the first limiting groove, the projection of the first connecting portion and the groove wall surface of the first limiting groove in the thickness direction of the wall portion do not overlap, thereby reducing the influence of the first limiting groove on the mutual welding connection between the lead-out piece and the busbar component, and improving the welding quality between the lead-out piece and the busbar component.

[0075] In a third aspect, the embodiments of the present application also provide a power utilization device comprising the battery monomer or the battery device. BRIEF DESCRIPTION OF DRAWINGS

[0076] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0077] Figure 1 A structural schematic diagram of a vehicle is provided for some embodiments of the present application;

[0078] Figure 2 An exploded view of a battery device is provided for some embodiments of the present application;

[0079] Figure 3 An assembly schematic diagram of a battery monomer and a busbar component is provided for some embodiments of the present application;

[0080] Figure 4 A structural schematic diagram of a battery monomer is provided for some embodiments of the present application;

[0081] Figure 5An exploded view of a battery cell according to some embodiments of the present application;

[0082] Figure 6 A partial cross-sectional view of a battery cell according to some embodiments of the present application;

[0083] Figure 7 A partial cross-sectional view of a battery cell according to some embodiments of the present application; Figure 6 An enlarged view of portion A of the battery cell shown in FIG. 8;

[0084] Figure 8 A partial cross-sectional view of a battery cell and a busbar member connected to each other according to some embodiments of the present application;

[0085] Figure 9 A partial cross-sectional view of a battery cell according to some embodiments of the present application;

[0086] Figure 10 A partial cross-sectional view of a battery cell and a busbar member connected to each other according to some embodiments of the present application;

[0087] Figure 11 A structural schematic view of a lead-out member of a first electrode terminal according to some embodiments of the present application;

[0088] Figure 12 A structural schematic view of a protective layer according to some embodiments of the present application;

[0089] Figure 13 A structural schematic view of a first insulating member according to some embodiments of the present application;

[0090] Figure 14 A structural schematic view of a protective layer according to some embodiments of the present application.

[0091] Icon: 1000 - vehicle; 100 - battery device; 10 - case; 11 - first case body; 12 - second case body; 20 - battery cell; 21 - shell; 211 - wall portion; 2111 - electrode lead-out hole; 2112 - fitting groove; 212 - housing; 2121 - opening; 213 - end cover; 22 - electrode assembly; 221 - main body portion; 222 - tab; 23 - electrode terminal; 23a - first electrode terminal; 23b - second electrode terminal; 231 - lead-out piece; 2311 - rivet hole; 2312 - first surface; 2313 - recess; 2314 - first limiting groove; 2314a - notch; 232 - connecting piece; 2321 - body portion; 2322 - limiting portion; 24 - first insulating piece; 241 - insulating main body; 2411 - fourth surface; 2412 - accommodating groove; 2413 - second limiting groove; 2414 - second through hole; 242 - flange portion; 25 - protective layer; 251 - second surface; 252 - third surface; 253 - first limiting protrusion; 254 - second limiting protrusion; 255 - first through hole; 26 - current collecting member; 27 - pressure relief member; 28 - second insulating piece; 29 - sealing piece; 30 - busbar member; 40 - connecting portion; 41 - first connecting portion; 42 - second connecting portion; 200 - controller; 300 - motor; X - thickness direction of wall portion. DETAILED DESCRIPTION

[0092] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0093] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the present application are only for the purpose of describing the specific embodiments of the present application and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification of the present application and the claims and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification of the present application and the claims or the above description of drawings are used to distinguish different objects, rather than to describe a particular sequence or primary and secondary relationship.

[0094] Reference to an "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another.

[0095] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0096] The term "and / or" in this application is only to describe the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0097] In the embodiments of the application, the same reference signs represent the same parts, and for the sake of brevity, the detailed description of the same parts is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0098] "Multiple" appearing in this application means more than two (including two).

[0099] In the embodiments of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging.

[0100] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead-acid battery, etc. The embodiments of the application are not limited in this regard.

[0101] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, which can prevent the positive and negative electrodes from short-circuiting to a certain extent, and at the same time allow the active ions to pass through.

[0102] In some embodiments, the cathode can be a cathode sheet, which can include a cathode current collector and a cathode active material disposed on at least one surface of the cathode current collector.

[0103] As an example, the cathode current collector has two surfaces opposite in the thickness direction thereof, and the cathode active material is disposed on either one or both of the two opposite surfaces of the cathode current collector.

[0104] As an example, the cathode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver plating on the surface, stainless steel with silver plating on the surface, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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 base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0105] As an example, the cathode active material can include at least one of lithium-containing phosphates, lithium transition metal oxides, and modified compounds thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as battery cathode active materials can also be used. These cathode active materials can be used alone only or in combination of two or more. Among them, examples of the lithium-containing phosphates can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxides can include, but are not limited to, lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to as NCM622 LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM 811 LiNi 0.85 Co 0.15 Al 0.05 O2) and modified compounds thereof.

[0106] In some embodiments, the positive electrode can employ a foam metal. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, etc. When the foam metal is used as the positive electrode, the foam metal surface can not be provided with the positive electrode active material, or of course can be provided with the positive electrode active material. As an example, the foam metal can also be filled or / and deposited with a lithium source material, a potassium metal or a sodium metal, the lithium source material being a lithium metal and / or a lithium-rich material.

[0107] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0108] As an example, the negative electrode current collector can employ a metal foil, a foam metal or a composite current collector. For example, as the metal foil, silver surface treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel or titanium, etc. can be employed. The foam metal can be a foam nickel, a foam copper, a foam aluminum, a foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector 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 base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0109] As an example, the negative electrode sheet can include the negative electrode current collector and the negative electrode active material provided on at least one surface of the negative electrode current collector.

[0110] As an example, the negative electrode current collector has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is provided on any one or both of the two opposite surfaces of the negative electrode current collector.

[0111] As an example, the negative active material can employ a negative active material for a battery cell known in the art. As an example, the negative active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative active material can also be used. These negative active materials can be used alone or in combination of two or more.

[0112] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0113] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0114] In some embodiments, the separator is a separator film. The separator film can be of various types, and any known porous structure separator film having good chemical stability and mechanical stability can be used.

[0115] As an example, the material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes.

[0116] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive and negative electrodes.

[0117] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0118] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium boric oxalate, lithium difluoroboric dioxalate, and lithium tetrafluorophosphoric oxalate.

[0119] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be selected from ether solvents. The ether solvents can include one or more of 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 ether.

[0120] In some embodiments, the gel electrolyte includes a polymer as a skeleton network of the electrolyte, and an ionic liquid-lithium salt.

[0121] In some embodiments, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0122] As an example, the polymer solid electrolyte can be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, cellulose, or the like.

[0123] As an example, the inorganic solid electrolyte can include one or more of oxide solid electrolytes (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superionic conductor (lithium germanium phosphorus sulfide, argyrodite), amorphous sulfide), and halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0124] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0125] In some embodiments, the electrode assembly is a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound into the jelly-roll structure.

[0126] In some embodiments, the electrode assembly is a stacked structure.

[0127] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be provided, and the plurality of positive electrode sheets and the plurality of negative electrode sheets can be alternately stacked.

[0128] As an example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked, and one positive electrode sheet can be interposed between adjacent folded segments.

[0129] As an example, the positive electrode sheet and the negative electrode sheet can be folded to form a plurality of folded segments that are stacked.

[0130] As an example, the separators can be provided in plurality, each provided between any adjacent positive electrode sheet or negative electrode sheet.

[0131] As an example, the separators can be provided in plurality, each provided between any adjacent positive electrode sheet or negative electrode sheet.

[0132] In some embodiments, the electrode assembly can have a shape of a cylinder, a flat, or a multi-prism, etc.

[0133] In some embodiments, the electrode assembly can be provided with tabs, which can lead current out of the electrode assembly. The tabs can include positive tabs and negative tabs.

[0134] In some embodiments, the battery cell can include a casing. The casing can be used to enclose components such as the electrode assembly and the electrolyte. The casing can be a steel casing, an aluminum casing, a plastic casing (e.g., polypropylene), a composite metal casing (e.g., a copper-aluminum composite casing), or an aluminum-plastic film, etc.

[0135] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, which can include but are not limited to a square battery cell, a blade battery cell, a multi-prismatic battery cell (e.g., a hexagonal battery cell), etc.

[0136] The battery device mentioned in the embodiments of the present application can include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly can include a plurality of battery cells connected in series, in parallel, or in a mixed connection through a busbar component.

[0137] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with a cable tie.

[0138] In some embodiments, the battery device can be a battery pack including a box and one or more battery cell assemblies housed in the box.

[0139] As an example, the battery cell assembly can be a battery module, which can be housed in the box by fixing the battery module in the box.

[0140] As an example, the battery cell assembly can also be housed in the box by directly fixing a plurality of battery cells in the box.

[0141] As an example, the box can include a first box body and a second box body. The first box body and the second box body are buckled so that the inside of the box forms a closed space to accommodate the battery monomer assembly. The closed here refers to covering or closing, which can be sealed or unsealed. The first box body can be a top cover or a bottom plate.

[0142] As an example, the box can include a top cover, a frame and a bottom plate. The top cover and the bottom plate are connected with the frame respectively, so that the inside of the box forms a closed space to accommodate the battery monomer assembly.

[0143] As an example, the box can be part of the chassis structure of the vehicle. For example, the top cover of the box can be at least part of the floor of the vehicle, or the frame of the box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0144] In some embodiments, the battery device refers to an energy storage device, and the energy storage device includes a box, at least one side of which is provided with a door. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0145] The battery device has the advantages of high energy density, small environmental pollution, large power density, long service life, wide adaptation range, small self-discharge coefficient, etc., and is an important part of the development of new energy today. The development of battery technology needs to consider many design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate and other performance parameters, in addition, the reliability of the battery device also needs to be considered.

[0146] For a general battery monomer, the battery monomer includes a shell and an electrode assembly contained in the shell, and an electrode terminal is arranged on an end cover of the shell. The electrode terminal includes a connecting piece and a lead-out piece connected with each other. The connecting piece is arranged in the end cover, and the lead-out piece is located outside the end cover. The input or output of the electric energy of the battery monomer can be realized by connecting the connecting piece of the electrode terminal with the tab of the electrode assembly. An insulating component is arranged between the end cover and the lead-out piece of the electrode terminal to reduce the risk of short circuit between the lead-out piece of the electrode terminal and the end cover through the insulating component. In the related art, when a plurality of battery monomers are assembled to form a battery device, a busbar component is usually arranged in the battery device to realize the series connection or parallel connection between the plurality of battery monomers in the battery device by welding the busbar component with the lead-out pieces of the electrode terminals of the plurality of battery monomers. However, in order to meet the penetration requirement of the welding connection between the lead-out piece of the electrode terminal and the busbar component, the electrode terminal of the battery monomer in the related art is prone to the risk of the lead-out piece of the electrode terminal being welded through when being welded with the busbar component, which easily causes the insulating component arranged between the lead-out piece and the end cover to be melted or damaged, thereby causing the risk of insulation failure between the lead-out piece and the end cover, and making the electrode terminal and the shell prone to short circuit during use, which is not conducive to improving the use reliability of the battery monomer.

[0147] In view of the above, in order to solve the problem of low reliability in use of the battery cell, the battery cell provided by the embodiments of the present application includes a shell, an electrode assembly, a first electrode terminal, a first insulating member and a protective layer. The shell has a wall portion. The electrode assembly is accommodated in the shell. The first electrode terminal is electrically connected with the electrode assembly, and the first electrode terminal includes a lead-out member located on the side of the wall portion away from the electrode assembly, and the lead-out member is used to be welded with a busbar and form a first connecting portion on the lead-out member. At least part of the first insulating member is arranged between the lead-out member and the wall portion in the thickness direction of the wall portion, and in the projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the first insulating member overlaps at least part of the orthographic projection of the first connecting portion. At least part of the protective layer is arranged between the lead-out member and the first insulating member, the melting point of the protective layer is greater than the melting point of the lead-out member, and in the projection plane perpendicular to the thickness direction of the wall portion, at least part of the orthographic projection of the first connecting portion is located in the orthographic projection of the protective layer.

[0148] In the battery cell with the above structure, the first electrode terminal is electrically connected with the electrode assembly, and the lead-out member of the first electrode terminal located on the side of the wall portion away from the electrode assembly is used to be welded with the busbar to realize the input or output of the electric energy of the battery cell through the first electrode terminal. In addition, the first insulating member is arranged between the lead-out member and the wall portion, so that the first insulating member can insulate and separate the lead-out member and the wall portion. However, since the orthographic projection of the first insulating member in the thickness direction of the wall portion overlaps at least part of the orthographic projection of the first connecting portion in the thickness direction of the wall portion, by arranging the protective layer between the lead-out member and the wall portion, the melting point of the protective layer is greater than the melting point of the lead-out member, and at least part of the orthographic projection of the first connecting portion in the thickness direction of the wall portion is located in the protective layer. Therefore, the protective layer can protect and separate the first insulating member when the lead-out member is welded with the busbar, so as to reduce the phenomenon that the lead-out member is burnt or melted after being welded through, thereby reducing the risk of the lead-out member being welded through without increasing the thickness of the lead-out member, so as to effectively reduce the risk of insulation failure between the lead-out member and the wall portion after the first insulating member is damaged while optimizing the thickness of the lead-out member, and further reducing the risk of short circuit of the first electrode terminal and the shell in use, thereby improving the reliability of the battery cell in use.

[0149] The battery cell disclosed by the embodiments of the present application can be used in an electric device such as a vehicle, a ship or an aircraft, etc. The power supply system of the electric device can be composed of the battery cell and the battery device disclosed by the present application. In this way, the problem that the battery cell is prone to short circuit in use can be solved, thereby improving the reliability of the battery cell in use.

[0150] The embodiments of the present application provide a power consumption device using a battery monomer or a battery device as a power supply. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft and the like. The electric toy can include a fixed or mobile electric toy, such as a game machine, an electric automobile toy, an electric ship toy and an electric aircraft toy and the like. The spacecraft can include an airplane, a rocket, a space shuttle and a spacecraft and the like.

[0151] The following embodiments are described by taking a power consumption device of an embodiment of the present application as a vehicle for example for convenience of description.

[0152] Please refer to Figure 1 , Figure 1 A structural schematic diagram of a vehicle 1000 provided by some embodiments of the present application is shown in FIG. 1. The vehicle 1000 can be a fuel automobile, a gas automobile or a new energy automobile. The new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile and the like. The vehicle 1000 is internally provided with a battery device 100. The battery device 100 can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery device 100 can be used to supply power for the vehicle 1000, for example, the battery device 100 can be used as an operating power supply or a use power supply of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power for the motor 300, for example, to meet the power consumption demand of the vehicle 1000 during starting, navigation and driving.

[0153] In some embodiments of the present application, the battery device 100 can not only be used as an operating power supply or a use power supply of the vehicle 1000, but also be used as a driving power supply of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1000.

[0154] Please refer to Figure 2 and Figure 3 , Figure 2 A structural exploded view of the battery device 100 provided by some embodiments of the present application is shown in FIG. 2. Figure 3 An assembly schematic diagram of a battery monomer 20 and a current collecting component 30 provided by some embodiments of the present application is shown in FIG. 3. Figure 4 A structural schematic diagram of the battery monomer 20 provided by some embodiments of the present application is shown in FIG. 4. The battery device 100 includes a box body 10 and the battery monomer 20. The battery monomer 20 is used to be accommodated in the box body 10.

[0155] The box body 10 is used to provide an assembling space for the battery monomer 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 can include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 are mutually covered, and the first box body 11 and the second box body 12 jointly define an assembling space for accommodating the battery monomer 20. The second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-shaped structure, which is covered on the open side of the second box body 12 to jointly define the assembling space with the second box body 12; or the first box body 11 and the second box body 12 can both be hollow structures with one side open, and the open side of the first box body 11 is covered on the open side of the second box body 12.

[0156] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can have various shapes, such as a cylinder, a cuboid or a square, etc. Exemplarily, in the embodiment shown in Figure 2 , the box body 10 has a cuboid shape.

[0157] In the battery device 100, the battery monomer 20 arranged in the box body 10 can be one or multiple. When the battery monomer 20 arranged in the box body 10 is multiple, the multiple battery monomers 20 can be in series connection, parallel connection or mixed connection, and the mixed connection means that the multiple battery monomers 20 are in both series connection and parallel connection. The multiple battery monomers 20 can be directly connected in series, parallel or mixed connection, and then the whole of the multiple battery monomers 20 is accommodated in the box body 10; of course, the battery device 100 can also be that the multiple battery monomers 20 are first connected in series, parallel or mixed connection to form a battery module, and then the multiple battery modules are connected in series, parallel or mixed connection to form a whole, which is accommodated in the box body 10.

[0158] In some embodiments, referring to Figure 3 , the battery device 100 can further include a current collecting component 30, which is used to connect the multiple battery monomers 20 to realize the electrical connection between the multiple battery monomers 20.

[0159] Each battery monomer 20 can be a secondary battery or a primary battery, and can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery monomer 20 can have a cuboid, a cylinder, a prism or other shapes, etc. Exemplarily, in the embodiment shown in Figure 4 , the battery monomer 20 has a cuboid structure.

[0160] According to some embodiments of the present application, referring to Figure 3 and Figure 4 , and further referring to Figure 5 , Figure 6 , Figure 7 and Figure 8, Figure 5 An exploded view of a battery cell 20 provided for some embodiments of the present application, Figure 6 A partial cross-sectional view of a battery cell 20 provided for some embodiments of the present application, Figure 7 A partial enlarged view of position A of the battery cell 20 shown in FIG. 1, Figure 6 A partial enlarged view of position A of the battery cell 20 shown in FIG. 1, Figure 8 A partial cross-sectional view of a battery cell 20 and a busbar component 30 after being connected to each other. The present application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, a first electrode terminal 23a, a first insulating member 24, and a protective layer 25. The housing 21 has a wall portion 211. The electrode assembly 22 is accommodated in the housing 21. The first electrode terminal 23a is electrically connected to the electrode assembly 22, and the first electrode terminal 23a includes a lead-out piece 231 located on a side of the wall portion 211 facing away from the electrode assembly 22, and the lead-out piece 231 is used for welding connection with the busbar component 30 and forming a first connection portion 41 on the lead-out piece 231. At least part of the first insulating member 24 is arranged between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion, and in a projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first insulating member 24 at least partially overlaps the orthographic projection of the first connection portion 41. At least part of the protective layer 25 is arranged between the lead-out piece 231 and the first insulating member 24, the melting point of the protective layer 25 is greater than the melting point of the lead-out piece 231, and in the projection plane perpendicular to the thickness direction X of the wall portion, at least part of the orthographic projection of the first connection portion 41 is located within the orthographic projection of the protective layer 25.

[0161] The housing 21 can also be used to accommodate an electrolyte, for example, an electrolyte solution. The housing 21 can have various structural forms, such as a cylinder or a cuboid, etc. Similarly, the material of the housing 21 can also be various, such as copper, iron, aluminum, steel, or aluminum alloy, etc.

[0162] In some embodiments, the housing 21 can be a sealed structure, or a non-sealed structure. As an example, when the housing 21 is a sealed structure, the housing 21 can play a role in protecting the electrode assembly 22 and to some extent preventing electrolyte leakage, etc. When the housing 21 is a non-sealed structure, the housing 21 can play a role in protecting the electrode assembly 22, and a sealing bag can be further included between the housing 21 and the electrode assembly 22, which is used to package the electrode assembly 22 and the electrolyte, etc. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum plastic film.

[0163] Optionally, the shell 21 can include a shell body 212 and an end cover 213, the shell body 212 has an accommodating cavity formed inside for accommodating the electrode assembly 22, and the accommodating cavity has an opening 2121, that is, the shell body 212 is a hollow structure with the opening 2121 formed at one end, and the end cover 213 is sealedly connected to the opening 2121 of the shell body 212 to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0164] The shell body 212 includes a bottom wall and a side wall, the bottom wall is arranged opposite to the end cover 213, the side wall is arranged around the bottom wall, and one end of the side wall is connected to the bottom wall and the other end of the side wall forms the opening 2121.

[0165] It should be noted that the wall portion 211 can be the end cover 213 of the shell 21, or can be a wall of the shell body 212 of the shell 21. Exemplarily, in Figure 4 and Figure 5 , the wall portion 211 is the end cover 213. Of course, the structure of the battery monomer 20 is not limited thereto, and in other embodiments, the wall portion 211 can also be the bottom wall of the shell body 212 arranged opposite to the end cover 213, and the wall portion 211 can also be the side wall of the shell body 212 adjacent to the end cover 213 and connected to each other.

[0166] In the assembly of the battery monomer 20, the electrode assembly 22 can be first placed into the shell body 212, and the electrolyte is filled into the shell body 212, and then the end cover 213 is sealed to the opening 2121 of the shell body 212 to complete the assembly of the battery monomer 20.

[0167] The shell body 212 can have various shapes, such as a cylindrical structure, a cuboid structure, or a prism structure, etc. The shape of the shell body 212 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a cylindrical shell body 212 can be selected; if the electrode assembly 22 is a cuboid structure, a cuboid shell body 212 can be selected. Of course, the structure of the end cover 213 can also be various, such as a plate structure or a hollow structure with one end open, etc. Exemplarily, in Figure 4 and Figure 5 , the shell body 212 is a cuboid structure.

[0168] Of course, it is understandable that the shell 21 is not limited to the above structure, and the shell 21 can also be other structures, for example, the shell 21 can include a shell body 212 and two end covers 213, the shell body 212 is a hollow structure with openings 2121 formed on opposite sides, and one end cover 213 corresponds to cover and form a sealed connection at one opening 2121 of the shell body 212 to form a sealed space for accommodating the electrode assembly 22 and the electrolyte, that is, the shell body 212 is formed with openings 2121 on opposite sides, and the two end covers 213 cover the two sides of the shell body 212 respectively to close the corresponding openings 2121.

[0169] Optionally, the structure of the electrode assembly 22 can be various, for example, the electrode assembly 22 can be a winding structure formed by winding the positive plate, the separator and the negative plate, or a laminated structure formed by laminating the positive plate, the separator and the negative plate.

[0170] Exemplarily, the separator is a separator film, and the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0171] Among them, the electrode assembly 22 includes a main body part 221 and a tab 222, the main body part 221 is the main part of the electrode assembly 22 for electrochemical reaction in the battery monomer 20, and exemplarily, in the Figure 5 Among them, the tab 222 is connected to one end of the main body part 221 facing the wall part 211 in the thickness direction X of the wall part, that is, in the thickness direction X of the wall part, the tab 222 is located between the main body part 221 and the wall part 211, so as to connect the tab 222 with the first electrode terminal 23a.

[0172] It should be noted that the tab 222 of the electrode assembly 22 is a part formed by mutually laminating the regions on the positive plate which are not coated with the positive active material layer or the regions on the negative plate which are not coated with the negative active material layer. If the tab 222 is the positive tab of the electrode assembly 22, the tab 222 is a part formed by mutually laminating the regions on the positive plate which are not coated with the positive active material layer; if the tab 222 is the negative tab of the electrode assembly 22, the tab 222 is a part formed by mutually laminating the regions on the negative plate which are not coated with the negative active material layer.

[0173] Optionally, the electrode assembly 22 accommodated in the shell 21 can be one or more. Exemplarily, in Figure 5 Among them, the shell 21 of the battery monomer 20 is provided with two electrode assemblies 22, and the two electrode assemblies 22 are laminated along the thickness direction of the battery monomer 20, of course, in other embodiments, the number of electrode assemblies 22 accommodated in the shell 21 of the battery monomer 20 can also be three, four, five or six, etc.

[0174] In the embodiment of the present application, the battery monomer 20 includes two electrode terminals 23, both of which serve to electrically connect the electrode assembly 22 as the positive and negative electrodes of the battery monomer 20, so as to be capable of matching the input or output of the electric energy of the battery monomer 20.

[0175] Among them, the two electrode terminals 23 include a first electrode terminal 23a and a second electrode terminal 23b with opposite polarities. For example, in the embodiment of the present application, the first electrode terminal 23a is the positive electrode of the battery monomer 20, and correspondingly, the second electrode terminal 23b is the negative electrode of the battery monomer 20. Of course, in other embodiments, the first electrode terminal 23a can also be the negative electrode of the battery monomer 20, and correspondingly, the second electrode terminal 23b is the positive electrode of the battery monomer 20.

[0176] In Figure 4 and Figure 5 , the first electrode terminal 23a and the second electrode terminal 23b are arranged on the wall portion 211, and correspondingly, each electrode assembly 22 has two tabs 222, both of which are connected to one end of the main body portion 221 facing the wall portion 211 in the thickness direction X of the wall portion. The two tabs 222 are oppositely polarized and arranged in a spaced manner, i.e. the two tabs 222 are the positive and negative tabs of the electrode assembly 22, respectively. The first electrode terminal 23a and the second electrode terminal 23b are electrically connected to the two tabs 222 of the electrode assembly 22, respectively, so as to realize the input or output of the electric energy of the battery monomer 20.

[0177] In Figure 6 , the electrode terminal 23 includes a lead-out piece 231 and a connecting piece 232. The lead-out piece 231 is located on the side of the wall portion 211 away from the electrode assembly 22 in the thickness direction X of the wall portion, and is used for welding connection with the busbar component 30. The connecting piece 232 is connected to the lead-out piece 231, and the connecting piece 232 is electrically connected to the tab 222 of the electrode assembly 22.

[0178] Among them, the connecting piece 232 and the tab 222 of the electrode assembly 22 can be directly connected structures, such as welding connection or abutment, etc., or can be indirectly connected structures, such as the tab 222 of the electrode assembly 22 being connected to the connecting piece 232 through other components.

[0179] In the embodiment of the present application, the current collecting component 30 is arranged on the side of the lead-out piece 231 away from the electrode assembly 22 in the thickness direction X of the wall portion, and the current collecting component 30 is welded to the lead-out piece 231. The lead-out piece 231 is used to be welded to the current collecting component 30 and form the first connecting portion 41 on the lead-out piece 231, that is, the first connecting portion 41 is a welding mark formed on the lead-out piece 231 after the lead-out piece 231 and the current collecting component 30 are welded to each other, that is, the lead-out piece 231 is welded to the current collecting component 30 and forms the connecting portion 40, the connecting portion 40 includes the first connecting portion 41 and the second connecting portion 42 connected to each other, the first connecting portion 41 is embedded in the lead-out piece 231, and the second connecting portion 42 is embedded in the current collecting component 30. Correspondingly, the connecting portion 40 is a region of mutual melting or a region of welding mark formed by the mutual welding of the lead-out piece 231 and the current collecting component 30. The first connecting portion 41 is the part of the connecting portion 40 embedded in the lead-out piece 231, and the second connecting portion 42 is the part of the connecting portion 40 embedded in the current collecting component 30, and the second connecting portion 42 and the first connecting portion 41 are connected to each other.

[0180] It should be noted that the current collecting component 30 is connected to the electrode terminals 23 of the plurality of battery monomers 20, which can be parallel connection between the plurality of battery monomers 20 through the current collecting component 30, or series connection between the plurality of battery monomers 20 through the current collecting component 30. Exemplarily, in the embodiment shown in Figure 3 , each current collecting component 30 connects the electrode terminals 23 with different polarities in the two adjacent battery monomers 20, that is, each current collecting component 30 connects the first electrode terminal 23a of one of the two adjacent battery monomers 20 and the second electrode terminal 23b of the other battery monomer 20 to realize series connection between the plurality of battery monomers 20.

[0181] Optionally, the connecting structure between the lead-out piece 231 and the connecting piece 232 can be various, such as welding connection or riveting, etc. Exemplarily, referring to Figure 6 , the connecting piece 232 and the lead-out piece 231 are riveted to each other, the lead-out piece 231 is provided with a riveting hole 2311 penetrating through the lead-out piece 231 in the thickness direction X of the wall portion, and the connecting piece 232 is inserted into the riveting hole 2311 in the thickness direction X of the wall portion and is riveted to the lead-out piece 231.

[0182] Referring to Figure 6 , the wall portion 211 is provided with an electrode lead-out hole 2111 penetrating through the wall portion 211 in the thickness direction X of the wall portion, and the connecting piece 232 is inserted into the electrode lead-out hole 2111 so as to connect the connecting piece 232 to the tab 222 of the electrode assembly 22.

[0183] The connecting piece 232 includes a body part 2321 and a limiting part 2322 connected with each other. The body part 2321 is arranged in the electrode lead-out hole 2111 and the riveting hole 2311 along the thickness direction X of the wall part, and the body part 2321 is riveted with the lead-out piece 231. The limiting part 2322 is protruded on the outer circumferential surface of the body part 2321, and the limiting part 2322 is located on the side of the wall part 211 facing the electrode assembly 22. The limiting part 2322 and the lead-out piece 231 can clamp the wall part 211 to assemble the electrode terminal 23 on the wall part 211.

[0184] It should be noted that, in the embodiment of the present application, the second electrode terminal 23b is the negative electrode of the battery monomer 20. Correspondingly, the lead-out piece 231 of the second electrode terminal 23b is usually a composite structure, that is, the lead-out piece 231 of the second electrode terminal 23b is a double-layer structure composed of two kinds of metal materials, such as hot rolling or cold rolling. Correspondingly, the material of one layer structure of the lead-out piece 231 of the second electrode terminal 23b is the same as that of the busbar 30, and the material of the other layer structure is the same as that of the negative tab of the electrode assembly 22.

[0185] In some embodiments, referring to Figure 5 As shown in the figure, the battery monomer 20 can also include two current collecting members 26, which are arranged in the housing 21 and are spaced apart. Each current collecting member 26 is used to connect the connecting piece 232 of one electrode terminal 23 and the tabs 222 of the same polarity in the plurality of electrode assemblies 22, so as to realize the electrical connection between the two electrode terminals 23 and the electrode assemblies 22, and facilitate the assembly difficulty between the tabs 222 and the electrode terminals 23.

[0186] For example, the current collecting member 26 is welded with the tab 222. Of course, in other embodiments, the current collecting member 26 and the tab 222 can also be abutted or clamped.

[0187] For example, the material of the current collecting member 26 can also be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0188] In the embodiment of the present application, the first insulating piece 24 serves to insulate and isolate the lead-out piece 231 and the wall part 211, so that the lead-out piece 231 is insulatively mounted on the wall part 211, and the lead-out piece 231 and the wall part 211 are not electrically connected.

[0189] Optionally, the material of the first insulating piece 24 can be various, such as rubber, plastic or silicone.

[0190] At least part of the first insulation piece 24 is arranged between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion, that is, the first insulation piece 24 can be a structure that is entirely located between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion, or can be a structure that is only partially located between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion.

[0191] Exemplarily, in the wall portion 21, the first insulation piece 24 is a structure that is only partially located between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion. Figure 6 and Figure 7 Exemplarily, in the wall portion 21, the first insulation piece 24 is a structure that is only partially located between the lead-out piece 231 and the wall portion 211 in the thickness direction X of the wall portion.

[0192] In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first insulation piece 24 at least partially overlaps the orthographic projection of the first connecting portion 41, that is, the welding marks formed on the lead-out piece 231 by the welding connection between the lead-out piece 231 and the busbar component 30 are at least partially located in the first insulation piece 24 in the projection in the thickness direction X of the wall portion.

[0193] In the embodiments of the present application, at least part of the protective layer 25 is arranged between the lead-out piece 231 and the first insulation piece 24, so as to separate the lead-out piece 231 and the first insulation piece 24 in the thickness direction X of the wall portion, and to alleviate the damage to the first insulation piece 24 caused by the welding connection between the lead-out piece 231 and the busbar component 30.

[0194] In the embodiments of the present application, the melting point of the protective layer 25 is greater than the melting point of the lead-out piece 231, that is, the protective layer 25 is more resistant to high temperature than the lead-out piece 231, and the temperature required for the protective layer 25 to be destroyed, decomposed, softened or melted is higher than the temperature required for the lead-out piece 231 to be melted.

[0195] Exemplarily, the material of the lead-out piece 231 is aluminum, and correspondingly, the protective layer 25 can be a metal material, such as copper, iron, steel or the like. Of course, the protective layer 25 can also be a non-metal material, such as ceramic or mica. It should be noted that in the embodiments in which the protective layer 25 is a non-metal material, if the protective layer 25 does not have a fixed melting point, that is, the melting point of the protective layer 25 is a range value, in the embodiments of the present application, the lowest melting point of the protective layer 25 of this material is greater than the melting point of the lead-out piece 231.

[0196] In the projection plane perpendicular to the thickness direction X of the wall portion, at least part of the orthographic projection of the first connecting portion 41 is located in the orthographic projection of the protective layer 25, that is, the welding marks formed on the lead-out piece 231 by the welding connection between the lead-out piece 231 and the busbar component 30 are at least partially located in the protective layer 25 in the projection in the thickness direction X of the wall portion, so that the protective layer 25 can separate the first insulation piece 24 and the first connecting portion 41 from each other in the thickness direction X of the wall portion.

[0197] In some embodiments, the protective layer 25 and the first electrode terminal 23a are separately disposed, that is, the protective layer 25 and the first electrode terminal 23a are two independent components. Along the thickness direction X of the wall portion, at least a portion of the protective layer 25 is disposed between the wall portion 211 and the lead-out member 231. In other words, the protective layer 25 is disposed on the side of the lead-out member 231 facing the wall portion 211 in the thickness direction X of the wall portion, so that the protective layer 25 and the lead-out member 231 are stacked in the thickness direction X of the wall portion.

[0198] Optionally, the protective layer 25 and the lead-out member 231 can be interconnected or unconnected. For example, in this embodiment, the protective layer 25 and the lead-out member 231 abut against each other along the first direction. Of course, in other embodiments, the protective layer 25 and the lead-out member 231 can also be bonded or welded together.

[0199] In some embodiments, see Figure 4 and Figure 5 As shown, the battery cell 20 may also include a pressure relief component 27, which is used to release the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0200] For example, the pressure relief component 27 is disposed on the end cap 213 of the housing 21. Of course, in other embodiments, the pressure relief component 27 may also be disposed on the housing 212 of the housing 21. Similarly, the pressure relief component 27 and the housing 21 may be integrally formed or separately disposed. If the pressure relief component 27 and the housing 21 are separately disposed, the pressure relief component 27 may be connected to the housing 21 by welding or other means. Correspondingly, the pressure relief component 27 may be a component such as an explosion-proof valve, explosion-proof disc, gas valve, pressure relief valve or safety valve. If the pressure relief component 27 and the housing 21 are integrally formed, the pressure relief component 27 is a region on the housing 21 with a weak structure, such as a region on the housing 21 with a groove.

[0201] In the embodiment, the first electrode terminal 23a is electrically connected with the electrode assembly 22, and the first electrode terminal 23a is located at the lead-out piece 231 on the side of the wall portion 211 away from the electrode assembly 22 for welding connection with the busbar component 30 to realize input or output of the electric energy of the battery monomer 20 through the first electrode terminal 23a. The first insulating piece 24 is arranged between the lead-out piece 231 and the wall portion 211, so that the first insulating piece 24 can insulate and separate the lead-out piece 231 and the wall portion 211. However, since the projection of the first insulating piece 24 in the thickness direction X of the wall portion at least partially overlaps with the projection of the first connecting portion 41 in the thickness direction X of the wall portion, by arranging the protective layer 25 between the lead-out piece 231 and the wall portion 211, the melting point of the protective layer 25 is greater than the melting point of the lead-out piece 231, and at least part of the projection of the first connecting portion 41 in the thickness direction X of the wall portion, which is formed by welding the lead-out piece 231 and the busbar component 30 and is located on the lead-out piece 231, is located in the protective layer 25. Therefore, the protective layer 25 can play a certain protection and separation role for the first insulating piece 24 when the lead-out piece 231 is welded and connected with the busbar component 30, so as to reduce the phenomenon that the first insulating piece 24 is burned or melted after the lead-out piece 231 is welded through. Therefore, it is not necessary to increase the thickness of the lead-out piece 231 to reduce the risk of the lead-out piece 231 being welded through, so that the thickness size of the lead-out piece 231 can be optimized while effectively reducing the risk of insulation failure between the lead-out piece 231 and the wall portion 211 after the first insulating piece 24 is damaged, thereby reducing the risk of short circuit of the first electrode terminal 23a and the shell 21 during use, and improving the use reliability of the battery monomer 20.

[0202] In some embodiments, referring to Figure 8 As shown, in the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 is entirely located in the orthographic projection of the protective layer 25. That is, the welding mark formed on the lead-out piece 231 by welding the lead-out piece 231 and the busbar component 30 with each other is a structure in which the projection in the thickness direction X of the wall portion falls entirely into the protective layer 25, so that the protective layer 25 can completely separate the first insulating piece 24 and the first connecting portion 41 in the thickness direction X of the wall portion.

[0203] In this embodiment, by welding the lead-out member 231 to the busbar 30 and projecting the first connecting portion 41 formed on the lead-out member 231 in the thickness direction X of the wall portion into a structure in which the entire portion is located within the protective layer 25, the protective layer 25 can effectively separate the first connecting wall and the first insulating member 24 in the thickness direction X of the wall portion. This further reduces the phenomenon of burning or melting the first insulating member 24 after the lead-out member 231 is welded through, thereby further reducing the risk of insulation failure between the lead-out member 231 and the wall portion 211 after the first insulating member 24 is damaged. This further reduces the risk of short circuit between the first electrode terminal 23a and the outer casing 21 during use, which is beneficial to further improve the reliability of the battery cell 20.

[0204] According to some embodiments of this application, see Figure 6 and Figure 7 As shown, the melting point of the protective layer 25 is T1, and the melting point of the lead-out part 231 is T2, satisfying that T1-T2≥200℃.

[0205] For example, the melting point T1 of the protective layer 25 may be 200°C, 205°C, 210°C, 220°C, 230°C, 240°C, 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 900°C, 1000°C, 1100°C, or 1200°C higher than the melting point T2 of the lead-in 231.

[0206] In this embodiment, by setting the melting point of the protective layer 25 to be 200 degrees Celsius or more higher than that of the lead-out member 231, the phenomenon of the protective layer 25 being melted when the lead-out member 231 is welded to the busbar component 30 is further alleviated. This can further improve the separation and barrier effect of the protective layer 25, which is beneficial to further improve the protection effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar component 30.

[0207] In some embodiments, the melting point of the protective layer 25 is T1, satisfying 1000℃≤T1≤3000℃.

[0208] For example, the melting point T1 of the protective layer 25 can be 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃, 1900℃, 2000℃, 2100℃, 2200℃, 2300℃, 2400℃, 2500℃, 2600℃, 2700℃, 2800℃, 2900℃, or 3000℃, etc.

[0209] In this embodiment, on the one hand, the melting point of the protective layer 25 is set to be greater than or equal to 1000 degrees Celsius so that the protective layer 25 has a better high-temperature resistance effect. This allows the protective layer 25 to play a better role in separating and protecting the first insulating component 24 when the lead-out component 231 is welded to the busbar component 30, thereby reducing the risk of the lead-out component 231 being burned or melted after being welded through. On the other hand, the melting point of the protective layer 25 is set to be less than or equal to 3000 degrees Celsius to alleviate the phenomenon of excessive high-temperature resistance of the protective layer 25. This reduces the difficulty of material selection and manufacturing of the protective layer 25, thereby reducing the manufacturing cost of the protective layer 25.

[0210] According to some embodiments of this application, see Figure 6 , Figure 7 and Figure 8 As shown, the lead-out member 231 and the protective layer 25 are stacked along the thickness direction X of the wall portion. In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the lead-out member 231 is located within the orthographic projection of the protective layer 25.

[0211] In the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the lead-out member 231 is located within the orthographic projection of the protective layer 25. That is, the projection of the lead-out member 231 in the thickness direction X of the wall is located within the protective layer 25, so that the protective layer 25 is a structure that covers the lead-out member 231 in the thickness direction X of the wall.

[0212] In this embodiment, by setting the lead-out member 231 and the protective layer 25 to be stacked along the thickness direction X of the wall, and the projection of the lead-out member 231 in the thickness direction X of the wall is located within the protective layer 25, the protective layer 25 can effectively separate the lead-out member 231 and the first insulating member 24 in the thickness direction X of the wall, thereby further improving the protective effect of the protective layer 25 on the first insulating member 24 when the lead-out member 231 is welded to the busbar 30, and further reducing the risk of the lead-out member 231 being burned or the first insulating member 24 being melted after being welded through.

[0213] According to some embodiments of this application, see Figure 6 and Figure 7 As shown, the maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is D1, which satisfies that D1 < 3mm.

[0214] The maximum dimension of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is D1, where D1 < 3mm. This means the maximum thickness of the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is less than 3mm, and therefore the space occupied by the protective layer 25 and the lead-out member 231 in the thickness direction X of the wall is less than 3mm. For example, see...Figure 6 and Figure 7 As shown in FIG. 17, if the protective layer 25 and the lead-out piece 231 are arranged in a stacked manner along the thickness direction X of the wall portion, the sum of the thickness of the protective layer 25 in the thickness direction X of the wall portion and the thickness of the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm; for example, as shown in FIG. 18, if the protective layer 25 is arranged on the first surface 2312 of the lead-out piece 231 in the thickness direction X of the wall portion, the sum of the thickness of the protective layer 25 in the thickness direction X of the wall portion and the thickness of the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm. Figure 9 and Figure 10 , Figure 9 FIG. 19 is a partial cross-sectional view of a battery cell 20 according to some embodiments of the present application, Figure 10 FIG. 20 is a partial cross-sectional view of the battery cell 20 and the busbar component 30 after being connected to each other according to some embodiments of the present application. If, in the embodiment in which the recess 2313 is arranged on the first surface 2312 of the lead-out piece 231 in the thickness direction X of the wall portion and the portion of the protective layer 25 is arranged in the recess 2313, the sum of the thickness of the lead-out piece 231 in the thickness direction X of the wall portion and the size of the portion of the protective layer 25 protruding from the first surface 2312 is less than 3 mm, and if the entire protective layer 25 is arranged in the recess 2313 in the thickness direction X of the wall portion, i.e., the protective layer 25 does not protrude from the first surface 2312 in the thickness direction X of the wall portion, the thickness of the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm.

[0215] In the present embodiment, since the separation effect of the protective layer 25 can reduce the risk of the lead-out piece 231 being welded through without increasing the thickness of the lead-out piece 231, the thickness of the lead-out piece 231 in the thickness direction X of the wall portion can be optimized to reduce the thickness of the lead-out piece 231 in the thickness direction X of the wall portion, and the maximum size of the entire protective layer 25 and the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm, which can save the space occupied by the first electrode terminal 23a and the protective layer 25 in the thickness direction X of the wall portion, optimize the overall size of the battery cell 20, and improve the energy density of the battery cell 20.

[0216] According to some embodiments of the present application, as shown in FIG. 17, Figure 6 and Figure 7 and Figure 9 As shown in FIG. 17, if the protective layer 25 and the lead-out piece 231 are arranged in a stacked manner along the thickness direction X of the wall portion, the sum of the thickness of the protective layer 25 in the thickness direction X of the wall portion and the thickness of the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm; for example, as shown in FIG. 18, if the protective layer 25 is arranged on the first surface 2312 of the lead-out piece 231 in the thickness direction X of the wall portion, the sum of the thickness of the protective layer 25 in the thickness direction X of the wall portion and the thickness of the lead-out piece 231 in the thickness direction X of the wall portion is less than 3 mm.

[0217] Exemplarily, the maximum dimension D1 of the protective layer 25 and the lead-out piece 231 as a whole in the thickness direction X of the wall portion can be 1.8 mm, 1.85 mm, 1.9 mm, 1.95 mm, 2 mm, 2.05 mm, 2.1 mm, 2.15 mm, 2.2 mm, 2.25 mm, 2.3 mm, 2.35 mm, 2.4 mm, 2.45 mm, 2.5 mm, 2.55 mm, 2.6 mm, 2.65 mm, 2.7 mm, 2.75 mm, or 2.8 mm, etc.

[0218] In the present embodiment, on the one hand, setting the maximum dimension of the protective layer 25 and the lead-out piece 231 as a whole in the thickness direction X of the wall portion to be greater than or equal to 1.8 mm can facilitate setting a thicker protective layer 25 and lead-out piece 231, which is conducive to improving the separation and protection effects of the protective layer 25 on the first insulating piece 24 when the lead-out piece 231 is welded to the busbar component 30, and is conducive to improving the structural strength of the lead-out piece 231 to reduce the risk of breakage or deformation of the lead-out piece 231 during use. On the other hand, setting the maximum dimension of the protective layer 25 and the lead-out piece 231 as a whole in the thickness direction X of the wall portion to be less than or equal to 2.8 mm can further save the space occupied by the lead-out piece 231 and the protective layer 25 as a whole in the thickness direction X of the wall portion, so as to further optimize the overall size of the battery monomer 20, which is conducive to further improving the energy density of the battery monomer 20.

[0219] According to some embodiments of the present application, as shown in Figure 6 and Figure 7 , along the thickness direction X of the wall portion, the thickness of the protective layer 25 is D2, and the thickness of the lead-out piece 231 is D3, which satisfies 0.1≤D2 / D3≤0.25.

[0220] wherein D2 is the maximum dimension of the protective layer 25 in the thickness direction X of the wall portion, and D3 is the maximum dimension of the lead-out piece 231 in the thickness direction X of the wall portion.

[0221] It should be noted that, as shown in Figure 9 , if in the embodiment in which the lead-out piece 231 is provided with a recess 2313 facing the first surface 2312 of the wall portion 211 in the thickness direction X of the wall portion, and part of the protective layer 25 is contained in the recess 2313, then D3 is the maximum distance between the surface of the lead-out piece 231 on the side away from the wall portion 211 in the thickness direction X of the wall portion and the first surface 2312.

[0222] Exemplarily, the thickness D2 of the protective layer 25 can be 0.1 times, 0.11 times, 0.12 times, 0.13 times, 0.14 times, 0.15 times, 0.16 times, 0.17 times, 0.18 times, 0.19 times, 0.2 times, 0.21 times, 0.22 times, 0.23 times, 0.24 times, or 0.25 times, etc. of the thickness D3 of the lead-out piece 231.

[0223] In the present embodiment, on the one hand, the thickness of the protective layer 25 is set to be greater than or equal to 0.1 times of the thickness of the lead-out piece 231, so that the protective layer 25 has sufficient thickness to separate and block when the lead-out piece 231 is welded to the busbar component 30, so as to alleviate the phenomenon that the protective layer 25 is welded through, and is beneficial to improve the separation effect and protection effect of the protective layer 25 on the first insulating piece 24 when the lead-out piece 231 is welded to the busbar component 30, on the other hand, the thickness of the protective layer 25 is set to be less than or equal to 0.25 times of the thickness of the lead-out piece 231, so as to reduce the waste phenomenon caused by the excessive thickness of the protective layer 25, and is beneficial to reduce the manufacturing cost of the battery monomer 20, and can save the space occupied by the protective layer 25 in the thickness direction X of the wall part, and is beneficial to optimize the overall size of the battery monomer 20.

[0224] According to some embodiments of the present application, referring to Figure 7 As shown in the figure, along the thickness direction X of the wall part, the thickness of the protective layer 25 is D2, which satisfies 0.3mm≤D2≤1mm, and further, 0.5mm≤D2≤0.8mm.

[0225] Exemplarily, the thickness D2 of the protective layer 25 in the thickness direction X of the wall part can be 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, or 1mm, etc.

[0226] In the present embodiment, on the one hand, the thickness of the protective layer 25 in the thickness direction X of the wall part is set to be greater than or equal to 0.3mm, which is beneficial to improve the structural strength of the protective layer 25, and makes the protective layer 25 have sufficient thickness to separate and block when the lead-out piece 231 is welded to the busbar component 30, so as to alleviate the phenomenon that the protective layer 25 is welded through, and is beneficial to improve the separation effect and protection effect of the protective layer 25 on the first insulating piece 24 when the lead-out piece 231 is welded to the busbar component 30, on the other hand, the thickness of the protective layer 25 in the thickness direction X of the wall part is set to be less than or equal to 1mm, so as to reduce the waste phenomenon caused by the excessive thickness of the protective layer 25, and is beneficial to reduce the manufacturing cost of the battery monomer 20, and can save the space occupied by the protective layer 25 in the thickness direction X of the wall part, and is beneficial to optimize the overall size of the battery monomer 20.

[0227] According to some embodiments of the present application, referring to Figure 7 As shown, along the thickness direction X of the wall portion, the thickness of the lead-out piece 231 is D3, which satisfies 1mm≤D3≤2.5mm, and further, 1.5mm≤D3≤2mm.

[0228] Exemplarily, the thickness D3 of the lead-out piece 231 in the thickness direction X of the wall portion can be 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm or 2.5mm, etc.

[0229] In the present embodiment, on one hand, the thickness dimension of the lead-out piece 231 in the thickness direction X of the wall portion is set to be greater than or equal to 1mm, which is beneficial to improve the structural strength of the lead-out piece 231, so as to reduce the risk of deformation or fracture of the lead-out piece 231 in the process of use, and can make the lead-out piece 231 have sufficient penetration when being welded with the busbar component 30, which is beneficial to improve the connection reliability and stability between the lead-out piece 231 and the busbar component 30, on the other hand, the thickness dimension of the lead-out piece 231 in the thickness direction X of the wall portion is set to be less than or equal to 2.5mm, so as to save the space occupied by the lead-out piece 231 in the thickness direction X of the wall portion, thereby being able to optimize the overall size of the battery monomer 20, which is beneficial to improve the energy density of the battery monomer 20.

[0230] According to some embodiments of the present application, referring to Figure 9 and Figure 10 As shown, along the thickness direction X of the wall portion, the lead-out piece 231 has a first surface 2312 facing the wall portion 211, and the first surface 2312 is provided with a recess 2313, and at least part of the protective layer 25 is accommodated in the recess 2313.

[0231] Wherein, the recess 2313 is a groove structure provided on the surface of the side of the lead-out piece 231 facing the wall portion 211, and the recess 2313 penetrates the outer peripheral surface of the lead-out piece 231.

[0232] At least part of the protective layer 25 is accommodated in the recess 2313, that is, the protective layer 25 is a structure inserted into the recess 2313 along the thickness direction X of the wall portion, so that the lead-out piece 231 is a structure whose projection in the thickness direction X of the wall portion is located in the protective layer 25.

[0233] In the embodiment, by arranging the recess 2313 on the first surface 2312 of the lead-out piece 231 facing the wall portion 211, and at least part of the protective layer 25 is accommodated in the recess 2313 along the thickness direction X of the wall portion, so as to realize that the protective layer 25 plays a separating role between the lead-out piece 231 and the first insulating piece 24, while also realizing that the protective layer 25 and the lead-out piece 231 share part of the space in the thickness direction X of the wall portion, which is beneficial to optimize the space occupied by the protective layer 25 and the lead-out piece 231 in the thickness direction X of the wall portion as a whole, and further can optimize the overall size of the battery monomer 20, so as to improve the energy density of the battery monomer 20.

[0234] In some embodiments, referring to Figure 9 As shown, along the thickness direction X of the wall portion, the protective layer 25 has a second surface 251 facing the wall portion 211, and the second surface 251 and the first surface 2312 are coplanar.

[0235] Among them, the second surface 251 and the first surface 2312 are coplanar, that is, the second surface 251 of the protective layer 25 facing the wall portion 211 and the first surface 2312 of the lead-out piece 231 where the recess 2313 is arranged are flush with each other, so that the protective layer 25 is accommodated in the recess 2313 as a whole.

[0236] Of course, in other embodiments, the protective layer 25 can also be a structure protruding from the first surface 2312, that is, the first surface 2312 is farther away from the wall portion 211 than the second surface 251 in the thickness direction X of the wall portion, and it can also be a structure that the first surface 2312 is closer to the wall portion 211 than the second surface 251 in the thickness direction X of the wall portion.

[0237] In the embodiment, by arranging the second surface 251 of the protective layer 25 facing the wall portion 211 and the first surface 2312 of the lead-out piece 231 facing the wall portion 211 to be coplanar with each other, so that the protective layer 25 is accommodated in the recess 2313 of the lead-out piece 231 as a whole, on the one hand, it can further optimize the space occupied by the protective layer 25 and the lead-out piece 231 in the thickness direction X of the wall portion as a whole, so as to further optimize the overall size of the battery monomer 20, which is beneficial to further improve the energy density of the battery monomer 20, on the other hand, through the recess 2313, the protective layer 25 can be stabilized and protected to a certain extent, which is beneficial to reduce the wear phenomenon of the protective layer 25 during use.

[0238] According to some embodiments of the present application, please refer to Figure 11 and Figure 12 , Figure 11 the structural schematic diagram of the lead-out piece 231 of the first electrode terminal 23a provided in some embodiments of the present application, Figure 12A structural schematic diagram of the protective layer 25 provided for some embodiments of the present application. Along the thickness direction X of the wall portion, the protective layer 25 has a third surface 252 away from the wall portion 211. The first limiting protrusion 253 is protruded on one of the surface of the lead-out piece 231 facing the wall portion 211 and the third surface 252, and the first limiting slot 2314 is arranged on the other one.

[0239] In some embodiments, the first limiting protrusion 253 can be protruded on the surface of the lead-out piece 231 facing the wall portion 211, and correspondingly, the first limiting slot 2314 is arranged on the third surface 252 of the protective layer 25. Of course, the first limiting protrusion 253 can be protruded on the third surface 252 of the protective layer 25, and correspondingly, the first limiting slot 2314 is arranged on the surface of the lead-out piece 231 facing the wall portion 211.

[0240] It should be noted that, in combination with the embodiments shown in Figure 6 , Figure 11 and Figure 12 , if the lead-out piece 231 and the protective layer 25 are arranged in a structure of being stacked along the thickness direction X of the wall portion, i.e., in the embodiment in which the first surface 2312 of the lead-out piece 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 away from the wall portion 211 are arranged to face each other, the first limiting protrusion 253 is protruded on one of the first surface 2312 of the lead-out piece 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 away from the wall portion 211, and the first limiting slot 2314 is arranged on the other one. See the embodiment shown in Figure 9 , if the recess 2313 is arranged on the first surface 2312 of the lead-out piece 231 facing the wall portion 211 in the thickness direction X of the wall portion, and part of the protective layer 25 is contained in the recess 2313, the first limiting protrusion 253 is protruded on one of the bottom surface of the protective layer 25 facing the recess 2313 in the thickness direction X of the wall portion and the third surface 252 of the protective layer 25 away from the wall portion 211, and the first limiting slot 2314 is arranged on the other one.

[0241] In the present embodiment, by arranging the first limiting protrusion 253 on one of the surface of the lead-out piece 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 away from the wall portion 211 and arranging the first limiting slot 2314 on the other one, the limiting and positioning between the protective layer 25 and the lead-out piece 231 are realized, so that the assembly precision between the protective layer 25 and the lead-out piece 231 can be improved, and the assembly stability between the protective layer 25 and the lead-out piece 231 can be improved, so as to reduce the risk of shaking or displacement of the protective layer 25 during use.

[0242] In some embodiments, see Figure 11 and Figure 12As shown in FIG. 13, the surface of the leading piece 231 facing the wall portion 211 is provided with a first limiting groove 2314, and the third surface 252 is provided with a first limiting protrusion 253. That is, the first limiting groove 2314 is arranged on the leading piece 231, and the first limiting protrusion 253 is arranged on the protective layer 25.

[0243] It should be noted that, in combination with Figure 6 , Figure 11 and Figure 12 , if the leading piece 231 and the protective layer 25 are arranged in a structure of being stacked along the thickness direction X of the wall portion, that is, in the embodiment in which the first surface 2312 of the leading piece 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 facing away from the wall portion 211 are arranged to face each other, the first limiting groove 2314 is arranged on the first surface 2312 of the leading piece 231 facing the wall portion 211. Referring to Figure 9 , if the first surface 2312 of the leading piece 231 facing the wall portion 211 is provided with a recess 2313 in the thickness direction X of the wall portion, and the part of the protective layer 25 is contained in the recess 2313, the first limiting groove 2314 is arranged on the bottom surface of the recess 2313 facing the protective layer 25 in the thickness direction X of the wall portion.

[0244] In the embodiment, by arranging the first limiting groove 2314 on the leading piece 231 and corresponding to arranging the first limiting protrusion 253 on the protective layer 25, the mutual limiting and positioning cooperation between the leading piece 231 and the protective layer 25 is achieved, and at the same time, the area of the protective layer 25 corresponding to the leading piece 231 is slotted, so as to reduce the influence of the first limiting groove 2314 on the structural strength of the protective layer 25 or the effect of the protective layer 25 separating the leading piece 231.

[0245] In some embodiments, please continue to refer to Figure 11 and Figure 12 , one of the surface of the leading piece 231 facing the wall portion 211 and the third surface 252 is provided with a plurality of first limiting protrusions 253, and the other is provided with a plurality of first limiting grooves 2314, and each first limiting protrusion 253 is inserted into the first limiting groove 2314.

[0246] Exemplarily, in Figure 11 , two first limiting grooves 2314 are arranged on the leading piece 231, and in Figure 12 , two first limiting protrusions 253 are arranged on the protective layer 25 corresponding to the protrusions, and the first limiting protrusions 253 and the first limiting grooves 2314 are one-to-one corresponding structures.

[0247] In the embodiment, a plurality of first limiting protrusions 253 are arranged on one of the surface of the lead-out piece 231 facing the wall portion 211 and the third surface 252 of the protective layer 25 away from the wall portion 211, and a plurality of first limiting grooves 2314 are correspondingly arranged on the other one, and each first limiting protrusion 253 cooperates with a first limiting groove 2314, so as to further improve the limiting effect between the protective layer 25 and the lead-out piece 231, thereby further improving the assembly stability between the protective layer 25 and the lead-out piece 231, and further reducing the risk of shaking or displacement of the protective layer 25 during use.

[0248] According to some embodiments of the present application, reference is made to Figure 6 and Figure 7 and further reference is made to Figure 13 , Figure 13 a structural schematic diagram of the first insulating piece 24 provided by some embodiments of the present application. The first insulating piece 24 can include an insulating body 241 and a flange portion 242. The insulating body 241 is arranged between the protective layer 25 and the wall portion 211 along the thickness direction X of the wall portion, and the flange portion 242 surrounds the outside of the lead-out piece 231, and the flange portion 242 is connected to the insulating body 241 at one end close to the electrode assembly 22 in the thickness direction X of the wall portion.

[0249] Among them, the first insulating piece 24 includes two parts connected to each other, namely the insulating body 241 and the flange portion 242, and the insulating body 241 is arranged between the protective layer 25 and the wall portion 211 along the thickness direction X of the wall portion, that is, the lead-out piece 231, the protective layer 25, the insulating body 241 and the wall portion 211 are sequentially stacked along the thickness direction X of the wall portion. Exemplarily, the insulating body 241 is a plate-shaped structure arranged between the protective layer 25 and the wall portion 211.

[0250] The flange portion 242 surrounds the outside of the lead-out piece 231, and the flange portion 242 is connected to the insulating body 241 at one end close to the electrode assembly 22 in the thickness direction X of the wall portion, that is, the flange portion 242 is an annular structure arranged around the lead-out piece 231 and the protective layer 25, and the flange portion 242 is connected to the surface of the side of the insulating body 241 away from the wall portion 211, so that the insulating body 241 and the flange portion 242 jointly form a recess structure accommodating the lead-out piece 231 and the protective layer 25.

[0251] Exemplarily, the insulating body 241 and the flange portion 242 are integrally formed structures, that is, the insulating body 241 and the flange portion 242 of the first insulating piece 24 are structures made by an integral molding process, such as injection molding or extrusion molding, etc. Of course, in other embodiments, the insulating body 241 and the flange portion 242 can also be a structure arranged separately, and the flange portion 242 can be connected to the insulating body 241 by bonding or clamping structure, etc.

[0252] It should be noted that in some embodiments, the first insulating member 24 can also not be provided with the flange portion 242, that is, the first insulating member 24 only includes the insulating body 241, and the insulating body 241 is arranged between the protective layer 25 and the wall portion 211 in the thickness direction X of the wall portion.

[0253] In the present embodiment, the first insulating member 24 is provided with the insulating body 241 located between the protective layer 25 and the wall portion 211 and the flange portion 242 arranged around the lead-out member 231, and one end of the flange portion 242 in the thickness direction X of the wall portion is connected with the insulating body 241, so that the insulating body 241 and the flange portion 242 jointly form a groove structure for accommodating the lead-out member 231 and the protective layer 25, which can further improve the insulation isolation effect of the first insulating member 24 between the lead-out member 231 and the wall portion 211, further reduce the risk of short circuit of the lead-out member 231 and the wall portion 211, on the one hand, and improve the assembly stability between the first insulating member 24 and the lead-out member 231, and improve the assembly reliability of the protective layer 25 arranged between the lead-out member 231 and the first insulating member 24, on the other hand.

[0254] According to some embodiments of the present application, in combination with Figure 12 and Figure 13 As shown, along the thickness direction X of the wall portion, the insulating body 241 has a fourth surface 2411 facing away from the wall portion 211, the flange portion 242 is protruding on the fourth surface 2411, the fourth surface 2411 is provided with an accommodation groove 2412, and at least part of the protective layer 25 is accommodated in the accommodation groove 2412.

[0255] The fourth surface 2411 is the surface of the insulating body 241 of the first insulating member 24 on the side facing the lead-out member 231 in the thickness direction X of the wall portion, and is also the surface of the insulating body 241 connected with the flange portion 242.

[0256] The fourth surface 2411 is provided with the accommodation groove 2412, and at least part of the protective layer 25 is accommodated in the accommodation groove 2412, that is, the surface of the insulating body 241 on the side facing the lead-out member 231 is provided with the accommodation groove 2412 for accommodating the protective layer 25. Optionally, the protective layer 25 can be a structure entirely accommodated in the accommodation groove 2412, or can be a structure only partially accommodated in the accommodation groove 2412. Exemplarily, in the present embodiment, the surface of the protective layer 25 on the side facing away from the wall portion 211 is closer to the wall portion 211 than the fourth surface 2411 in the thickness direction X of the wall portion, so that the protective layer 25 is a structure not extending out of the accommodation groove 2412 in the thickness direction X of the wall portion.

[0257] In the embodiment, by arranging the accommodating groove 2412 on the fourth surface 2411 of the insulating body 241 facing the lead-out piece 231, and arranging at least part of the protective layer 25 in the accommodating groove 2412, the protective layer 25 and the insulating body 241 of the first insulating piece 24 can share part of the space in the thickness direction X of the wall part, which is beneficial to optimize the space occupied by the protective layer 25 and the insulating body 241 in the thickness direction X of the wall part as a whole, so as to optimize the overall size of the battery monomer 20, and improve the energy density of the battery monomer 20.

[0258] In some embodiments, referring to Figure 13 , and further referring to Figure 14 , Figure 14 The structure diagram of the protective layer 25 provided in some other embodiments of the present application is shown. The outer circumferential surface of the protective layer 25 is provided with a second limiting protrusion 254, and the groove side surface of the accommodating groove 2412 is provided with a second limiting groove 2413, and the second limiting protrusion 254 is inserted into the second limiting groove 2413.

[0259] In some embodiments, referring to

[0260] Optionally, the second limiting protrusion 254 protruding on the outer circumferential surface of the protective layer 25 can be one or more, and correspondingly, the second limiting groove 2413 provided on the groove side surface of the accommodating groove 2412 corresponds to the second limiting protrusion 254 one by one.

[0261] It should be noted that in other embodiments, the second limiting protrusion 254 can also protrude on the groove side surface of the accommodating groove 2412, and correspondingly, the second limiting groove 2413 is provided on the outer circumferential surface of the protective layer 25.

[0262] In the embodiment, by protruding the second limiting protrusion 254 on the outer circumferential surface of the protective layer 25, and correspondingly arranging the second limiting groove 2413 on the groove side surface of the accommodating groove 2412 which cooperates with the second limiting protrusion 254, the limiting and positioning between the protective layer 25 and the insulating body 241 of the first insulating piece 24 is realized, which on one hand can improve the assembly precision of the protective layer 25 arranged in the accommodating groove 2412, so as to improve the assembly quality of the protective layer 25 arranged between the lead-out piece 231 and the first insulating piece 24, and on the other hand can realize the circumferential locking between the protective layer 25 and the insulating body 241, so as to reduce the phenomenon of circumferential rotation of the protective layer 25 relative to the insulating body 241 of the first insulating piece 24.

[0263] In some embodiments, please continue to refer toFigure 13 and Figure 14 As shown in

[0264] Exemplarily, in a projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the protective layer 25 and the orthographic projection of the accommodating groove 2412 are both rectangular, and each side of the orthographic projection of the protective layer 25 is provided with one second limiting protrusion 254. Correspondingly, the four groove sides of the accommodating groove 2412 are respectively provided with one second limiting groove 2413, and each second limiting groove 2413 is inserted and matched with one first limiting protrusion 253. Of course, in other embodiments, the number of the second limiting protrusions 254 protruding on the outer circumferential surface of the protective layer 25 and the number of the second limiting grooves 2413 provided on the groove side of the accommodating groove 2412 can also be two, three, five, six, or seven, etc.

[0265] In this embodiment, by protruding the plurality of second limiting protrusions 254 spaced apart on the outer circumferential surface of the protective layer 25, and correspondingly providing the plurality of second limiting grooves 2413 corresponding to the second limiting protrusions 254 on the groove side of the accommodating groove 2412, the limiting effect and positioning effect between the protective layer 25 and the insulating body 241 of the first insulating piece 24 are further improved. On the one hand, the assembly precision of the protective layer 25 arranged in the accommodating groove 2412 can be further improved, so as to further improve the assembly quality of the protective layer 25 arranged between the lead-out piece 231 and the first insulating piece 24. On the other hand, the phenomenon of the protective layer 25 rotating relative to the insulating body 241 of the first insulating piece 24 can be further reduced.

[0266] In some embodiments, as shown in Figure 13

[0267] In this embodiment, by setting the second limiting groove 2413 as a structure penetrating through the fourth surface 2411, the second limiting groove 2413 is a structure penetrating through the fourth surface 2411 and the groove side of the accommodating groove 2412 at the same time, so as to reduce the difficulty of setting the second limiting groove 2413 on the groove side of the accommodating groove 2412, and reduce the manufacturing difficulty of the first insulating piece 24.

[0268] According to some embodiments of the present application, as shown in Figure 6 Figure 7 Figure 9 ​​​As shown, along the thickness direction X of the wall portion, the surface of the wall portion 211 away from the electrode assembly 22 is provided with a fitting groove 2112, and at least part of the first insulating member 24 is accommodated in the fitting groove 2112.

[0269] In the embodiments shown in Figure 6 and Figure 9 , at least part of the first insulating member 24 is partially accommodated in the fitting groove 2112.

[0270] It should be noted that in the embodiments in which the first insulating member 24 includes the insulating body 241 and the flange portion 242, at least part of the insulating body 241 is accommodated in the fitting groove 2112 along the thickness direction X of the wall portion.

[0271] In the present embodiment, by providing the fitting groove 2112 on the surface of the wall portion 211 away from the electrode assembly 22, and accommodating at least part of the first insulating member 24 in the fitting groove 2112, the battery monomer 20 adopting such a structure can on one hand play a certain limiting and positioning effect on the first insulating member 24 through the fitting groove 2112, which is conducive to reducing the difficulty of assembling the first insulating member 24 between the wall portion 211 and the lead-out member 231, and reducing the phenomenon of shaking or displacement of the first insulating member 24 during use, which is conducive to improving the assembly stability of the first insulating member 24, and on the other hand, the first insulating member 24 and the wall portion 211 can share part of the space in the thickness direction X of the wall portion, which is conducive to optimizing the overall size of the battery monomer 20.

[0272] According to some embodiments of the present application, as shown in Figure 6 and Figure 9 , the wall portion 211 is provided with an electrode lead-out hole 2111, and the electrode lead-out hole 2111 penetrates the wall portion 211 along the thickness direction X of the wall portion. The first electrode terminal 23a can further include a connecting member 232 connected with the lead-out member 231, and the connecting member 232 is arranged in the electrode lead-out hole 2111 and is electrically connected with the electrode assembly 22.

[0273] In the embodiments shown in and

[0274] , the lead-out member 231 and the connecting member 232 of the first electrode terminal 23a are connected with each other, the lead-out member 231 is used for welding connection with the bus member 30, and the connecting member 232 is electrically connected with the tab 222 of the electrode assembly 22, so as to realize the input or output of the electric energy of the battery monomer 20 through the first electrode terminal 23a.Optionally, the connection structure between the lead-out piece 231 and the connecting piece 232 can be various, such as welding connection or riveting, etc.

[0275] The connecting piece 232 is arranged in the electrode lead-out hole 2111 and is electrically connected with the electrode assembly 22, that is, the connecting piece 232 is partially arranged in the electrode lead-out hole 2111, and the connecting piece 232 is partially arranged inside the shell 21, so as to facilitate the assembly connection between the connecting piece 232 and the tab 222 of the electrode assembly 22.

[0276] In the embodiment, the wall portion 211 is provided with the electrode lead-out hole 2111 penetrating the wall portion 211 along the thickness direction X of the wall portion, and the first electrode terminal 23a is further provided with the connecting piece 232 connected with the lead-out piece 231, the connecting piece 232 is arranged in the electrode lead-out hole 2111 and can be electrically connected with the electrode assembly 22 arranged in the shell 21, so as to realize the input or output of the electric energy of the battery monomer 20 through the first electrode terminal 23a, which is simple in structure and facilitates assembly.

[0277] In some embodiments, as shown in Figure 6 and Figure 9 , the connecting piece 232 can include a body portion 2321 and a limiting portion 2322. The body portion 2321 is arranged in the electrode lead-out hole 2111 along the thickness direction X of the wall portion, and the body portion 2321 is connected with the lead-out piece 231, and the limiting portion 2322 is protruded on the outer circumferential surface of the body portion 2321. Along the thickness direction X of the wall portion, the limiting portion 2322 is located on the side of the wall portion 211 facing the electrode assembly 22, and at least part of the wall portion 211 is located between the limiting portion 2322 and the lead-out piece 231.

[0278] The body portion 2321 of the connecting piece 232 is arranged in the electrode lead-out hole 2111 of the wall portion 211 along the thickness direction X of the wall portion, and the body portion 2321 is connected with the lead-out piece 231 located on the side of the wall portion 211 away from the electrode assembly 22. It should be noted that in the embodiment in which the protective layer 25 is arranged between the lead-out piece 231 and the first insulating piece 24, as shown in Figure 12 , the first through hole 255 is further arranged on the protective layer 25 for the body portion 2321 to pass through, and the first through hole 255 penetrates the protective layer 25 along the thickness direction X of the wall portion. Similarly, the second through hole 2414 is further arranged on the first insulating piece 24 for the body portion 2321 to pass through, and in the embodiment in which the first insulating piece 24 includes the insulating body and the flange portion 242, the second through hole 2414 is arranged on the insulating body, and the second through hole 2414 penetrates the insulating body along the thickness direction X of the wall portion. In the embodiment in which the fourth surface 2411 of the insulating body is provided with the receiving groove 2412, the second through hole 2414 penetrates the bottom surface of the receiving groove 2412, so that the second through hole 2414 and the receiving groove 2412 are in communication with each other.

[0279] Optionally, the connecting structure between the body part 2321 and the leading piece 231 can be various, such as riveting, welding connection or clamping, etc.

[0280] The limiting part 2322 is protruded on the outer circumferential surface of the body part 2321, that is, the limiting part 2322 is a structure connected to the outer circumferential surface of the body part 2321. Exemplarily, the limiting part 2322 and the body part 2321 are integrally formed, that is, the body part 2321 and the limiting part 2322 of the connecting piece 232 are structures made by an integral forming process, such as stamping or casting, etc. Of course, in other embodiments, the limiting part 2322 and the body part 2321 can also be a structure provided separately, and the limiting part 2322 can be connected to the body part 2321 by a welding connection or the like.

[0281] Along the thickness direction X of the wall part, the limiting part 2322 is located on the side of the wall part 211 facing the electrode assembly 22, and at least part of the wall part 211 is located between the limiting part 2322 and the leading piece 231, that is, the limiting part 2322 and the leading piece 231 are respectively located on both sides of the wall part 211 in the thickness direction X of the wall part, and the limiting part 2322 and the leading piece 231 can cooperate to clamp at least part of the wall part 211 to realize the assembly of the first electrode terminal 23a to the wall part 211.

[0282] In the present embodiment, the connecting piece 232 of the first electrode terminal 23a is provided with the body part 2321 and the limiting part 2322 protruded on the outer circumferential surface of the body part 2321, the body part 2321 is connected with the leading piece 231, and the limiting part 2322 is located on the side of the wall part 211 away from the leading piece 231, so that at least part of the wall part 211 is located between the limiting part 2322 and the leading piece 231, so that the limiting part 2322 and the leading piece 231 can cooperate to clamp the wall part 211, thereby realizing the assembly of the first electrode terminal 23a to the wall part 211. The structure is simple, easy to assemble, and can improve the structural stability of the assembly of the first electrode terminal 23a to the wall part 211.

[0283] According to some embodiments of the present application, as shown in Figure 6 and Figure 9 The battery monomer 20 can further include a second insulating piece 28, and along the thickness direction X of the wall part, at least part of the second insulating piece 28 is arranged between the limiting part 2322 and the wall part 211 to insulate and isolate the limiting part 2322 and the wall part 211.

[0284] The second insulating piece 28 is arranged on the side of the wall portion 211 facing the electrode assembly 22, and a part of the second insulating piece 28 is located between the limiting portion 2322 and the wall portion 211, so that the second insulating piece 28 can insulate and separate the limiting portion 2322 and the wall portion 211, so that the second insulating piece 28 and the first insulating piece 24 can cooperate to achieve the first electrode terminal 23a insulatedly mounted on the wall portion 211, and a part of the second insulating piece 28 is located between the wall portion 211 and the electrode assembly 22, so that the second insulating piece 28 can also insulate and separate the electrode assembly 22 and the wall portion 211.

[0285] Exemplarily, the material of the second insulating piece 28 can be various, such as plastic, rubber, or silicone, etc.

[0286] In the embodiment, the second insulating piece 28 is further arranged between the limiting portion 2322 and the wall portion 211, so that the second insulating piece 28 can insulate and separate the limiting portion 2322 and the wall portion 211, thereby reducing the risk of short circuit between the limiting portion 2322 and the wall portion 211, and reducing the short circuit phenomenon of the battery monomer 20 in use.

[0287] According to some embodiments of the present application, referring to Figure 6 The body portion 2321 and the lead-out piece 231 are riveted.

[0288] In combination with Figure 6 and Figure 11 As shown, the lead-out piece 231 is provided with a riveting hole 2311 penetrating through the surfaces of the two sides of the lead-out piece 231 along the thickness direction X of the wall portion, and correspondingly, the body portion 2321 of the connecting piece 232 is inserted into the riveting hole 2311 and riveted with the lead-out piece 231.

[0289] It should be noted that in other embodiments, the lead-out piece 231 and the body portion 2321 of the connecting piece 232 can also be connected by welding or clamping.

[0290] In the embodiment, by arranging the body portion 2321 of the connecting piece 232 and the lead-out piece 231 to be riveted with each other, the connection stability between the connecting piece 232 and the lead-out piece 231 is improved, the risk of connection failure of the first electrode terminal 23a in use is reduced, and the connection difficulty between the connecting piece 232 and the lead-out piece 231 is reduced, thereby improving the assembly efficiency of the battery monomer 20.

[0291] According to some embodiments of the present application, referring to Figure 6 and Figure 9As shown, the battery cell 20 can further include a sealing member 29. The sealing member 29 is arranged between the connecting member 232 and the wall portion 211, and is configured to seal the gap between the connecting member 232 and the hole wall surface of the electrode lead-out hole 2111.

[0292] The sealing member 29 can be made of various materials, such as silica gel, plastic, rubber, etc.

[0293] For example, at least part of the sealing member 29 extends into the electrode lead-out hole 2111, so that at least part of the sealing member 29 is located between the connecting member 232 and the hole wall surface of the electrode lead-out hole 2111. It should be noted that in the embodiment in which the connecting member 232 includes the body portion 2321 and the limiting portion 2322, the sealing member 29 is arranged outside the body portion 2321, so that at least part of the sealing member 29 is located between the outer circumferential surface of the body portion 2321 and the hole wall surface of the electrode lead-out hole 2111.

[0294] In this embodiment, the battery cell 20 further includes the sealing member 29. By arranging the sealing member 29 between the wall portion 211 and the connecting member 232 of the first electrode terminal 23a, the sealing member 29 can seal the gap between the connecting member 232 and the hole wall surface of the electrode lead-out hole 2111, thereby reducing the risk of leakage of the battery cell 20 at the electrode lead-out hole 2111, and improving the stability and reliability of the battery cell 20.

[0295] According to some embodiments of the present application, referring to Figure 6 and Figure 9 As shown, the material of the lead-out member 231 includes aluminum, and the material of the protective layer 25 includes steel, copper, ceramic or mica.

[0296] In this embodiment, the material of the lead-out member 231 includes aluminum, so that the lead-out member 231 has good electrical conductivity, and the low melting point of aluminum facilitates the welding connection of the lead-out member 231 and the busbar component 30, thereby reducing the assembly difficulty between the lead-out member 231 and the busbar component 30. The material of the protective layer 25 includes steel, copper, ceramic or mica, so that the protective layer 25 has a high melting point, so that the protective layer 25 is not easily welded or melted when the lead-out member 231 and the busbar component 30 are welded, thereby improving the separation and protection effects of the protective layer 25 on the wall portion 211 or other components.

[0297] According to some embodiments of the present application, referring to Figure 4 , Figure 5 and Figure 6As shown, the first electrode terminal 23a is the positive electrode of the battery cell 20, that is, the first electrode terminal 23a is electrically connected to the positive electrode of the electrode assembly 22.

[0298] In this embodiment, by setting the first electrode terminal 23a as the positive terminal of the battery cell 20, the first electrode terminal 23a can be used as the positive output terminal of the battery cell 20 to input or output the electrical energy of the battery cell 20.

[0299] According to some embodiments of this application, see Figure 4 and Figure 5 As shown, the housing 21 may include a housing 212 and an end cap 213. The housing 212 has an internal cavity with an opening 2121, in which the electrode assembly 22 is housed. The end cap 213 closes the opening 2121 and is a wall portion 211.

[0300] The end cap 213 is a wall portion 211, that is, the first electrode terminal 23a is installed on the end cap 213, and the lead-out part 231 of the first electrode terminal 23a is located on the side of the end cap 213 away from the electrode assembly 22. Correspondingly, the first insulating member 24 is disposed between the lead-out part 231 and the end cap 213.

[0301] In this embodiment, by setting the wall portion 211 of the outer casing 21 as an end cap 213 for closing the opening 2121 of the housing 212, the battery cell 20 with this structure is convenient to assemble the first electrode terminal 23a on the end cap 213 and to assemble and connect the first electrode terminal 23a with the electrode assembly 22. It is also convenient to set a protective layer 25 between the lead-out member 231 and the first insulating member 24, thereby reducing the assembly difficulty of the battery cell 20 and improving the production efficiency of the battery cell 20.

[0302] It should be noted that the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can also have other structures. For example, the outer casing 21 can include a housing 212 and an end cap 213. The housing 212 includes an integrally formed side wall and a bottom wall. The side wall surrounds the bottom wall. Along the thickness direction X of the wall portion, one end of the side wall is connected to the bottom wall, and the other end forms an opening 2121. The side wall and the bottom wall together define a receiving cavity. The electrode assembly 22 is received in the receiving cavity. The end cap 213 closes the opening 2121. The bottom wall is the wall portion 211. That is, the wall portion 211 is the bottom wall of the housing 212 that is opposite to the end cap 213 in the thickness direction X of the wall portion. That is, the first electrode terminal 23a is disposed on the bottom wall of the housing 212, and the lead-out member 231 of the first electrode terminal 23a is located on the side of the bottom wall of the housing 212 away from the electrode assembly 22. Correspondingly, the first insulating member 24 is disposed between the lead-out member 231 and the bottom wall of the housing 212.

[0303] The shell 212 includes a side wall and a bottom wall that are integrally formed, that is, the shell 212 is manufactured by an integral forming process such as stamping, casting or extrusion forming, that is, the side wall and the bottom wall of the shell 212 are in an integral structure.

[0304] In the present embodiment, by setting the wall portion 211 of the shell 21 as one wall of the shell 212 that is arranged opposite to the end cover 213 in the thickness direction X of the wall portion, the battery monomer 20 adopting such a structure can make the region of the shell 21 where the first electrode terminal 23a is mounted away from the end cover 213, and make the wall portion 211 and the end cover 213 not have a direct connection relationship, thereby being able to alleviate the phenomenon that the force generated when the first electrode terminal 23a and other components pull or twist the wall portion 211 acts on the end cover 213, so as to reduce the risk of connection failure between the end cover 213 and the shell 212, and further facilitate reducing the risk of liquid leakage of the battery monomer 20 in use.

[0305] According to some embodiments of the present application, in combination with Figure 2 , Figure 3 and Figure 4 , the present application further provides a battery device 100, which includes the current-conducting component 30 and the battery monomer 20 of any one of the above solutions. The current-conducting component 30 is arranged on the side of the lead-out piece 231 away from the protective layer 25 in the thickness direction X of the wall portion, and the current-conducting component 30 is welded to the lead-out piece 231 to form a connection portion 40, the connection portion 40 includes a first connection portion 41 and a second connection portion 42 connected to each other, the first connection portion 41 is embedded in the lead-out piece 231, and the second connection portion 42 is embedded in the current-conducting component 30.

[0306] The current-conducting component 30 serves to electrically connect the battery monomers 20 in the battery device 100, and the material of the current-conducting component 30 can be various, such as copper, aluminum or aluminum alloy.

[0307] The current-conducting component 30 is arranged on the side of the lead-out piece 231 away from the protective layer 25 in the thickness direction X of the wall portion, that is, the current-conducting component 30 and the lead-out piece 231 of the first electrode terminal 23a are arranged in a stacked structure in the thickness direction X of the wall portion, and the lead-out piece 231 is located between the current-conducting component 30 and the protective layer 25 in the thickness direction X of the wall portion, so that the current-conducting component 30 is located on the side of the lead-out piece 231 away from the electrode assembly 22, and the protective layer 25 is located on the side of the lead-out piece 231 facing the electrode assembly 22.

[0308] The busbar component 30 is welded to the lead-out piece 231 and forms a connection portion 40, i.e., the connection portion 40 is a region where the lead-out piece 231 and the busbar component 30 are welded to each other and are fused to each other or a region where the lead-out piece 231 and the busbar component 30 are welded to each other and form a welding mark. The first connection portion 41 is a portion of the connection portion 40 embedded in the lead-out piece 231, and the second connection portion 42 is a portion of the connection portion 40 embedded in the busbar component 30, and the second connection portion 42 and the first connection portion 41 are connected to each other. Correspondingly, the first connection portion 41 is a welding mark formed on the lead-out piece 231 by welding the lead-out piece 231 and the busbar component 30 to each other, and the second connection portion 42 is a welding mark formed on the busbar component 30 by welding the lead-out piece 231 and the busbar component 30 to each other. Of course, in some embodiments, the connection portion 40 can further include a third portion, which is a portion of the connection portion 40 protruding on a surface of the busbar component 30 away from the lead-out piece 231, and the second connection portion 42 connects the first connection portion 41 and the third portion.

[0309] Referring to Figure 2 As shown, the battery device 100 can further include a box body 10, and the battery cell 20 is accommodated in the box body 10.

[0310] In some embodiments, the box body 10 can include a first box body 11 and a second box body 12, and the first box body 11 and the second box body 12 are overlapped with each other, and the first box body 11 and the second box body 12 together define an assembly space for accommodating the battery cell 20.

[0311] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-shaped structure, and the first box body 11 is overlapped with the open side of the second box body 12, so that the first box body 11 and the second box body 12 together define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 is overlapped with the open side of the second box body 12.

[0312] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can have various shapes, such as a cylinder or a cuboid, etc. Exemplarily, in Figure 2 , the box body 10 is a cuboid structure.

[0313] Optionally, the battery cell 20 arranged in the box body 10 can be one or multiple. Exemplarily, in Figure 2In the embodiment, the plurality of battery cells 20 are arranged in the box 10 of the battery device 100, and the plurality of battery cells 20 are electrically connected by the busbar component 30 in series, in parallel, or in a mixed connection. The mixed connection means that the plurality of battery cells 20 are connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series, in parallel, or in a mixed connection, and the plurality of battery cells 20 are arranged in the box 10. Alternatively, the plurality of battery cells 20 are connected in series, in parallel, or in a mixed connection to form a battery module, and the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and the whole is arranged in the box 10.

[0314] It should be noted that in some embodiments, the battery device 100 can not be provided with the box 10. The battery device 100 includes the plurality of battery cells 20, and the battery device 100 formed by the plurality of battery cells 20 can be directly assembled to the electric device to provide electric energy for the electric device by the plurality of battery cells 20. That is, the box 10 can be part of the electric device. Taking the vehicle 1000 as an example of the electric device, the box 10 can be part of the chassis structure of the vehicle 1000. For example, part of the box 10 can be at least part of the floor of the vehicle 1000, or part of the box 10 can be at least part of the cross beam and the longitudinal beam of the vehicle 1000.

[0315] In the embodiment, the busbar component 30 is welded to the lead-out piece 231 of the first electrode terminal 23a, and the first connecting portion 41 is formed on the lead-out piece 231 and the second connecting portion 42 is formed on the busbar component 30. The first connecting portion 41 and the second connecting portion 42 are connected to each other to achieve the assembly connection between the first electrode terminal 23a and the busbar component 30. The battery device 100 with the structure can improve the connection stability and firmness between the first electrode terminal 23a and the busbar component 30, and is conducive to improving the overcurrent effect between the first electrode terminal 23a and the busbar component 30.

[0316] According to some embodiments of the present application, as shown in Figure 8 and Figure 10 In the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the outer edge of the front projection of the first connecting portion 41 and the front projection of the protective layer 25 is L1, which satisfies 1mm≤L1≤2.5mm.

[0317] In the embodiment, the busbar component 30 is welded to the lead-out piece 231 of the first electrode terminal 23a, and the first connecting portion 41 is formed on the lead-out piece 231 and the second connecting portion 42 is formed on the busbar component 30. The first connecting portion 41 and the second connecting portion 42 are connected to each other to achieve the assembly connection between the first electrode terminal 23a and the busbar component 30. The battery device 100 with the structure can improve the connection stability and firmness between the first electrode terminal 23a and the busbar component 30, and is conducive to improving the overcurrent effect between the first electrode terminal 23a and the busbar component 30. Figure 12As shown, the protective layer 25 is provided with a first through hole 255 through which the connecting piece 232 of the first electrode terminal 23a passes, and in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the orthographic projection of the first connecting portion 41 and the orthographic projection of the outer circumferential surface of the protective layer 25 is L1, and in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the orthographic projection of the first connecting portion 41 and the orthographic projection of the hole wall surface of the first through hole 255 is also L1.

[0318] Exemplarily, L1 can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or 2.5 mm.

[0319] In the present embodiment, on the one hand, the minimum distance between the orthographic projection of the first connecting portion 41 in the protective layer 25 along the thickness direction X of the wall portion and the outer edge of the protective layer 25 is greater than or equal to 1 mm, so as to improve the effect of the protective layer 25 in separating the area where the lead-out piece 231 forms a weld mark, thereby facilitating further improvement of the protection effect of the protective layer 25 on the first insulating piece 24, so as to further reduce the risk that the lead-out piece 231 is welded through and affects the first insulating piece 24, and on the other hand, the minimum distance between the orthographic projection of the first connecting portion 41 in the protective layer 25 along the thickness direction X of the wall portion and the outer edge of the protective layer 25 is less than or equal to 2.5 mm, so as to alleviate the phenomenon that the area for mutual welding of the lead-out piece 231 and the bus member 30 is limited due to the distance being too large, thereby being able to increase the size of the connecting portion 40 formed by mutual welding of the lead-out piece 231 and the bus member 30, so as to further improve the connection stability and overcurrent effect between the lead-out piece 231 and the bus member 30.

[0320] According to some embodiments of the present application, as shown in Figure 8 and Figure 10 in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the orthographic projection of the first connecting portion 41 and the outer edge of the orthographic projection of the lead-out piece 231 is L2, and 1 mm≤L2≤2.5 mm is satisfied.

[0321] in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the orthographic projection of the first connecting portion 41 and the orthographic projection of the outer circumferential surface of the lead-out piece 231 is L2, that is, in the projection plane perpendicular to the thickness direction X of the wall portion, the minimum distance between the orthographic projection of the first connecting portion 41 and the orthographic projection of the outer circumferential surface of the lead-out piece 231 is L2. Of course, as shown in Figure 11As shown, in the embodiment where the lead-out piece 231 is provided with the riveting hole 2311 riveted with the connecting piece 232, the minimum distance between the orthographic projection of the first connecting part 41 and the orthographic projection of the hole wall surface of the riveting hole 2311 in the projection plane perpendicular to the thickness direction X of the wall part is also L2.

[0322] Exemplarily, L2 can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or 2.5 mm.

[0323] In the present embodiment, on one hand, the minimum distance between the orthographic projection of the first connecting part 41 in the projection plane perpendicular to the thickness direction X of the wall part and the outer edge of the orthographic projection of the lead-out piece 231 in the projection plane perpendicular to the thickness direction X of the wall part is set to be greater than or equal to 1 mm, so as to increase the distance between the area of the lead-out piece 231 forming the welding mark and the outer edge of the lead-out piece 231, and facilitate the reduction of the phenomenon of melting of the outer edge of the lead-out piece 231, thereby being capable of improving the welding quality between the lead-out piece 231 and the busbar part 30, on the other hand, the minimum distance between the orthographic projection of the first connecting part 41 in the projection plane perpendicular to the thickness direction X of the wall part and the outer edge of the orthographic projection of the lead-out piece 231 in the projection plane perpendicular to the thickness direction X of the wall part is set to be less than or equal to 2.5 mm, so as to alleviate the phenomenon that the area of the lead-out piece 231 for mutual welding with the busbar part 30 is limited due to the excessively large distance, thereby being capable of increasing the size of the connecting part 40 formed by mutual welding between the lead-out piece 231 and the busbar part 30, so as to further improve the connection stability and overcurrent effect between the lead-out piece 231 and the busbar part 30.

[0324] According to some embodiments of the present application, referring to Figure 8 and Figure 10 As shown, along the thickness direction X of the wall part, the thickness of the area where the busbar part 30 and the lead-out piece 231 are welded and connected is D4, and 1.2 mm≤D4≤3 mm is satisfied.

[0325] Among them, along the thickness direction X of the wall part, the thickness of the area where the busbar part 30 and the lead-out piece 231 are welded and connected is D4, and correspondingly, the maximum size of the second connecting part 42 of the connecting part 40 embedded in the busbar part 30 in the thickness direction X of the wall part is also D4.

[0326] Exemplarily, D4 can be 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, or 3 mm, etc.

[0327] In the embodiment, by setting the thickness of the region where the bus member 30 is mutually welded with the lead-out piece 231 to be 1.2 mm to 3 mm, on the one hand, setting the thickness of the region where the bus member 30 is mutually welded with the lead-out piece 231 to be greater than or equal to 1.2 mm can improve the overcurrent performance of the bus member 30, so as to improve the conduction effect of the bus member 30, and at the same time of improving the overcurrent performance of the bus member 30, the welding power and the welding molten pool between the bus member 30 and the lead-out piece 231 will be larger, so that by setting the protective layer 25 on the side of the lead-out piece 231 facing the wall portion 211, the region where the lead-out piece 231 is welded and penetrated can be effectively separated, so as to reduce the risk of affecting other components after the lead-out piece 231 is penetrated, on the other hand, setting the thickness of the region where the bus member 30 is mutually welded with the lead-out piece 231 to be less than or equal to 3 mm can reduce the phenomenon of excessive waste or excessive welding power required by the bus member 30, so as to reduce the welding difficulty between the bus member 30 and the lead-out piece 231, and reduce the manufacturing cost of the bus member 30.

[0328] According to some embodiments of the present application, as shown in Figure 8 , Figure 10 , Figure 11 and Figure 12 , along the thickness direction X of the wall portion, the surface of the lead-out piece 231 facing the wall portion 211 is provided with a first limiting groove 2314, the protective layer 25 has a third surface 252 away from the wall portion 211, the third surface 252 is provided with a first limiting protrusion 253, and the first limiting protrusion 253 is inserted and matched with the first limiting groove 2314. The first limiting groove 2314 is formed with a slot 2314a on the surface of the lead-out piece 231 facing the wall portion 211, and in the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 is located outside the orthographic projection of the slot 2314a.

[0329] In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 is located outside the orthographic projection of the slot 2314a, that is, in the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the first connecting portion 41 and the orthographic projection of the slot wall surface of the first limiting groove 2314 do not overlap, that is, the projection of the first connecting portion 41 in the thickness direction X of the wall portion does not fall into the first limiting groove 2314.

[0330] In the embodiment, the first limiting groove 2314 is arranged on the surface of the lead-out piece 231 facing the wall portion 211, and the first limiting protrusion 253 corresponding to the first limiting groove 2314 is arranged on the third surface 252 of the protective layer 25 away from the wall portion 211, so as to realize the limiting and positioning between the protective layer 25 and the lead-out piece 231, thereby improving the assembly precision and stability between the protective layer 25 and the lead-out piece 231. The first connecting portion 41 of the connecting portion 40 is arranged outside the slot opening 2314a of the first limiting groove 2314 in the thickness direction X of the wall portion, so that the projection of the first connecting portion 41 and the slot wall surface of the first limiting groove 2314 in the thickness direction X of the wall portion are not overlapped, thereby reducing the influence of the first limiting groove 2314 on the welding connection between the lead-out piece 231 and the busbar component 30, and improving the welding quality between the lead-out piece 231 and the busbar component 30.

[0331] According to some embodiments of the present application, the present application also provides a power consuming device, the power consuming device comprising the battery cell 20 of any one of the above solutions or the battery device 100 of any one of the above solutions, and the battery cell 20 or the battery device 100 is used to provide electric energy for the power consuming device.

[0332] Among them, the power consuming device can be the equipment or system of the above-mentioned any application battery cell 20 or battery device 100.

[0333] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0334] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized by, The application relates to a battery electrode terminal, comprising: a housing having a wall portion; an electrode assembly accommodated in the housing; a first electrode terminal electrically connected with the electrode assembly, the first electrode terminal comprising a lead-out piece on a side of the wall portion away from the electrode assembly, and the lead-out piece is used for being welded with a bus member and forming a first connecting portion on the lead-out piece; a first insulating piece arranged between the lead-out piece and the wall portion in at least a thickness direction of the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, a normal projection of the first insulating piece at least partially overlaps a normal projection of the first connecting portion; and a protective layer arranged between the lead-out piece and the first insulating piece in at least a part, a melting point of the protective layer is greater than a melting point of the lead-out piece, and in the projection plane perpendicular to the thickness direction of the wall portion, at least a part of a normal projection of the first connecting portion is located in a normal projection of the protective layer. In the projection plane perpendicular to the thickness direction of the wall portion, the normal projection of the first connecting portion is entirely located in the normal projection of the protective layer.

2. The battery cell of claim 1, wherein, The melting point of the protective layer is T1, and the melting point of the lead-out piece is T2, and T1-T2 is greater than or equal to 200 DEG C.

3. The battery cell of claim 1, wherein, The melting point of the protective layer is T1, and 1000 DEG C is less than or equal to T1 and is less than or equal to 3000 DEG C.

4. The battery cell of claim 1, wherein, The lead-out piece and the protective layer are arranged in a stacking mode along the thickness direction of the wall portion.

5. The battery cell of claim 1, wherein, In the projection plane perpendicular to the thickness direction of the wall portion, the normal projection of the lead-out piece is located in the normal projection of the protective layer. The maximum dimension of the protective layer and the lead-out piece in the thickness direction of the wall portion is D1, and D1 is less than 3 mm.

6. The battery cell of claim 1, wherein, 1.8 mm is less than or equal to D1 and is less than or equal to 2.8 mm.

7. The battery cell of claim 6, wherein, Along the thickness direction of the wall portion, the thickness of the protective layer is D2, and the thickness of the lead-out piece is D3, and 0.1 is less than or equal to D2 / D3 and is less than or equal to 0.

25.

8. The battery cell of claim 1, wherein, 0.3 mm is less than or equal to D2 and is less than or equal to 1 mm.

9. The battery cell of claim 8, wherein, 1 mm is less than or equal to D3 and is less than or equal to 2.5 mm.

10. The battery cell of claim 9, wherein, Along the thickness direction of the wall portion, the lead-out piece has a first surface facing the wall portion, the first surface is provided with a recess, and at least a part of the protective layer is accommodated in the recess.

11. The battery cell of claim 1, wherein, Along the thickness direction of the wall portion, the protective layer has a second surface facing the wall portion, and the second surface is coplanar with the first surface.

12. The battery cell of claim 11, wherein, Along the thickness direction of the wall portion, the protective layer has a third surface away from the wall portion.

13. The battery cell of any one of claims 1-12, wherein, One of the surface of the lead-out piece facing the wall portion and the third surface is provided with a first limiting protrusion, and the other is provided with a first limiting groove, and the first limiting protrusion and the first limiting groove are inserted and matched. The surface of the lead-out piece facing the wall portion is provided with the first limiting groove, and the third surface is provided with the first limiting protrusion.

14. The battery cell of claim 13, wherein, One of the surface of the lead-out piece facing the wall portion and the third surface is provided with a plurality of first limiting protrusions, and the other is provided with a plurality of first limiting grooves, and each first limiting protrusion is inserted into the first limiting groove.

15. The battery cell of claim 13, wherein, The first insulating piece comprises:

16. The battery cell of any one of claims 1-12, wherein, an insulating body arranged between the protective layer and the wall portion in the thickness direction of the wall portion; ​ A flanged portion surrounds the outside of the lead-out member, and the flanged portion is connected to the insulating body at one end of the wall portion near the electrode assembly in the thickness direction.

17. The battery cell of claim 16, wherein, Along the thickness direction of the wall portion, the insulating body has a fourth surface facing away from the wall portion, and the flange portion protrudes from the fourth surface; The fourth surface is provided with a receiving groove, and at least a portion of the protective layer is contained within the receiving groove.

18. The battery cell of claim 17, wherein, The outer peripheral surface of the protective layer is provided with a second limiting protrusion, and the side of the receiving groove is provided with a second limiting groove, and the second limiting protrusion is inserted into the second limiting groove.

19. The battery cell of claim 18, wherein, The outer peripheral surface of the protective layer is provided with a plurality of second limiting protrusions, which are arranged at intervals along the circumference of the protective layer. The side of the receiving groove is provided with a plurality of second limiting grooves, and each second limiting protrusion is inserted into a second limiting groove.

20. The battery cell of claim 18, wherein, The second limiting groove penetrates the fourth surface along the thickness direction of the wall portion.

21. The battery cell of any one of claims 1-12, wherein, Along the thickness direction of the wall portion, a mounting groove is provided on the surface of the wall portion opposite to the electrode assembly, and at least a portion of the first insulating member is accommodated in the mounting groove.

22. The battery cell of any one of claims 1-12, wherein, The wall portion is provided with an electrode lead-out hole, which penetrates the wall portion along the thickness direction; The first electrode terminal further includes a connector connected to the lead-out member, which passes through the electrode lead-out hole and is electrically connected to the electrode assembly.

23. The battery cell of claim 22, wherein, The connector includes: The main body is inserted into the electrode lead-out hole along the thickness direction of the wall portion, and the main body is connected to the lead-out member; A limiting part protrudes from the outer peripheral surface of the main body; Wherein, along the thickness direction of the wall portion, the limiting portion is located on the side of the wall portion facing the electrode assembly, and at least a portion of the wall portion is located between the limiting portion and the lead-out member.

24. The battery cell of claim 23, wherein, The battery cell further includes a second insulating member, at least a portion of which is disposed between the limiting portion and the wall portion along the thickness direction of the wall portion to insulate and isolate the limiting portion and the wall portion.

25. The battery cell of claim 23, wherein, The main body and the lead-out part are riveted together.

26. The battery cell of claim 22, wherein, The battery cell also includes: A seal is disposed between the connector and the wall portion, the seal being configured to seal the gap between the connector and the wall surface of the electrode lead-out hole.

27. The battery cell of any one of claims 1-12, wherein, The material of the lead-out element includes aluminum, and the material of the protective layer includes steel, copper, ceramic or mica.

28. The battery cell of any one of claims 1-12, wherein, The first electrode terminal is the positive electrode of the battery cell.

29. The battery cell of any one of claims 1-12, wherein, The outer casing includes: The housing has an internally formed receiving cavity with an opening, and the electrode assembly is received within the receiving cavity; End cap, to close the opening; The end cap is the wall portion.

30. The battery cell of any one of claims 1-12, wherein, The outer casing includes: The housing includes an integrally formed sidewall and a bottom wall. The sidewall surrounds the bottom wall. Along the thickness direction of the wall portion, one end of the sidewall is connected to the bottom wall, and the other end forms an opening. The sidewall and the bottom wall together define a receiving cavity, in which the electrode assembly is received. End cap, to close the opening; The bottom wall is the wall portion.

31. A battery device, characterized by include: The battery cell of any one of claims 1-30; And The busbar component is arranged on the side of the lead-out piece away from the protective layer in the thickness direction of the wall part, and is welded to the lead-out piece to form a connecting part, the connecting part includes a first connecting part and a second connecting part connected to each other, the first connecting part is embedded in the lead-out piece, and the second connecting part is embedded in the busbar component.

32. The battery device of claim 31, wherein, In the projection plane perpendicular to the thickness direction of the wall part, the minimum distance between the outer edge of the front projection of the first connecting part and the front projection of the protective layer is L1, and 1mm≤L1≤2.5mm is satisfied.

33. The battery device of claim 31, wherein, In the projection plane perpendicular to the thickness direction of the wall part, the minimum distance between the outer edge of the front projection of the first connecting part and the front projection of the lead-out piece is L2, and 1mm≤L2≤2.5mm is satisfied.

34. The battery device of claim 31, wherein, In the thickness direction of the wall part, the thickness of the area where the busbar component is welded to the lead-out piece is D4, and 1.2mm≤D4≤3mm is satisfied.

35. The battery device of any one of claims 31-34, wherein, In the thickness direction of the wall part, the surface of the lead-out piece facing the wall part is provided with a first limiting groove, and the protective layer has a third surface away from the wall part, and the third surface is provided with a first limiting protrusion, and the first limiting protrusion is inserted into the first limiting groove. Wherein, the first limiting groove forms a notch on the surface of the lead-out piece facing the wall part, and in the projection plane perpendicular to the thickness direction of the wall part, the front projection of the first connecting part is located on the outside of the front projection of the notch.

36. An electrical device, comprising: The battery cell of any one of claims 1-30; or The battery device of any one of claims 31-35.

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