Battery monomer, battery device and electric device

Abstract

A battery cell (100), a battery device (1100) and a power utilization device, the battery cell (100) comprising a housing (200) and an electrode assembly (101), the housing (200) being provided with an electrode lead-out portion (2011); at least part of the electrode assembly (101) is arranged in the shell (200), the electrode assembly (101) comprises a first pole piece (1), the first pole piece (1) comprises a current collector (10), a conductive component (30) and an active material layer (20), and the conductive component (30) is electrically connected with the electrode leading-out part (2011); the current collector (10) comprises an insulating substrate (11) and a metal layer (12), the insulating substrate (11), the metal layer (12) and the active material layer (20) are stacked in the thickness direction of the current collector (10), and at least part of the metal layer (12) is located between the insulating substrate (11) and the active material layer (20); the metal layer (12) comprises a first metal part (121) and a second metal part (122) which are arranged along a first direction and connected with each other, and the first direction is perpendicular to the thickness direction of the current collector (10); at least part of the first metal part (121) is covered with the active material layer (20), and at least part of the second metal part (122) is not covered with the active material layer (20); the conductive member (30) is welded on the surface of the second metal part (122) back to the insulating substrate (11) and forms a first welding mark (51); the electrode assembly (101) comprises a first insulating part (41), and the first insulating part (41) covers at least part of the first welding mark (51).

Description

Battery cell, battery device and electric device

[0001] This application claims priority to International Patent Application PCT / CN2024 / 106988 entitled "Battery cell, battery device and electric device" filed on July 23, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the technical field of battery, and in particular relates to a battery cell, a battery device and an electric device. BACKGROUND

[0003] Battery cells are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc.

[0004] A battery device includes one or more battery cells to meet different capacity usage requirements; however, in the technical field of battery cells, how to improve the usage reliability of battery cells is an important research direction.

[0005] The above statements are only used to provide background technical information related to the present application, and do not necessarily constitute the prior art.

[0006] SUMMARY

[0007] The purpose of the embodiments of the present application is to provide a battery cell, a battery device and an electric device, which can improve the usage reliability of the battery cell.

[0008] The technical solution adopted by the embodiments of the present application is:

[0009] In some embodiments, a battery cell is provided, which includes a housing and an electrode assembly, the housing is provided with an electrode lead-out portion; at least part of the electrode assembly is arranged in the housing, the electrode assembly includes a first electrode tab, the first electrode tab includes a current collector, a conductive member and an active material layer, the conductive member is electrically connected with the electrode lead-out portion; the current collector includes an insulating base body and a metal layer, the insulating base body, the metal layer and the active material layer are stacked along the thickness direction of the current collector, at least part of the metal layer is located between the insulating base body and the active material layer; the metal layer includes a first metal portion and a second metal portion arranged and connected along a first direction, the first direction is perpendicular to the thickness direction of the current collector; at least part of the first metal portion is covered with the active material layer, at least part of the second metal portion is not covered with the active material layer; the conductive member is welded to the surface of the second metal portion away from the insulating base body and forms a first welding mark; the electrode assembly includes a first insulating member, the first insulating member covers at least part of the first welding mark.

[0010] By adopting the technical scheme of the embodiment, the first insulating piece covers at least part of the first welding mark, can block burrs of the first welding mark, reduces the risk of short circuit of the battery monomer, and is beneficial to improve the use reliability of the battery monomer; the current collector adopts the composite structure of the insulating base body and the metal layer, the thickness of the metal layer is small relative to the pure metal current collector, burrs generated in the manufacturing process of the current collector are small, the risk of internal short circuit of the battery monomer is reduced, and the use reliability of the battery monomer is improved.

[0011] In some embodiments, in a direction from the first metal part to the second metal part, the first insulating piece protrudes from the edge of the first welding mark away from the active material layer; and / or, in a direction from the second metal part to the first metal part, the first insulating piece protrudes from the edge of the first welding mark close to the active material layer.

[0012] By adopting the technical scheme of the embodiment, the first insulating piece can block burrs at the edges of the relative distribution of the first welding mark in the first direction, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0013] In some embodiments, the conductive member includes a first connecting part and at least one second connecting part, the first connecting part and the second connecting part are connected, the second connecting part is electrically connected with the electrode lead-out part, and the first connecting part is welded to the surface of the second metal part away from the insulating base body and forms the first welding mark.

[0014] By adopting the technical scheme of the embodiment, the second connecting part is provided, which can facilitate the connection of the second connecting part with the electrode lead-out part, and the manufacturing of the battery monomer is more convenient.

[0015] In some embodiments, the second metal part includes at least one protruding part; in the second direction, the sum of the sizes of all the protruding parts is less than the size of the first metal part, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector; the first connecting part includes at least one first connecting sub-part, the first connecting sub-part is connected with the second connecting part, the first connecting sub-part covers the surface of the protruding part away from the insulating base body, and the first connecting sub-part corresponds to the protruding part one by one.

[0016] By adopting the technical scheme of the embodiment, in the second direction, the size of all the protruding parts is less than the size of the first metal part, the size of the protruding part in the second direction is small, space can be saved, and the volume energy density of the battery monomer is improved.

[0017] In some embodiments, the first insulating piece includes at least one first insulating part, the first insulating part covers the surface of the first connecting sub-part away from the protruding part, and the first connecting sub-part corresponds to the first connecting sub-part one by one.

[0018] By adopting the technical scheme of the embodiment, the first insulating portion covers the first connecting sub-portion, so that the insulation of the first connecting sub-portion can be realized, and the short circuit risk of the battery monomer can be reduced, and the use reliability of the battery monomer can be improved.

[0019] In some embodiments, the first welding mark includes at least one first welding mark portion, the first connecting sub-portion is welded to the surface of the protruding portion away from the insulating base and forms the first welding mark portion, and the first insulating portion covers at least part of the first welding mark portion.

[0020] By adopting the technical scheme of the embodiment, the first connecting sub-portion is welded to the protruding portion, the connection between the first connecting sub-portion and the protruding portion is realized, the structure is simple, and the manufacturing is convenient; the first insulating portion can block burrs on the first welding mark portion, the short circuit risk of the battery monomer can be reduced, and the use reliability of the battery monomer can be improved.

[0021] In some embodiments, the protruding portion includes a first protruding sub-portion and a second protruding sub-portion, the first protruding sub-portion is connected between the second protruding sub-portion and the first metal portion, the size of the first protruding sub-portion is greater than the size of the second protruding sub-portion along the second direction, the first welding mark portion includes a first welding sub-portion, the first connecting portion is welded to the first protruding sub-portion and forms the first welding sub-portion, and the first insulating portion covers at least part of the first welding sub-portion; and / or, the first welding mark portion includes a second welding sub-portion, the first connecting portion is welded to the second protruding sub-portion and forms the second welding sub-portion, and the first insulating portion covers at least part of the second welding sub-portion.

[0022] By adopting the technical scheme of the embodiment, the size of the first protruding sub-portion is greater along the second direction, which is beneficial to improve the welding area of the first protruding sub-portion and the first connecting portion, improve the flow area between the protruding portion and the first connecting portion, improve the flow capacity between the protruding portion and the first connecting portion, reduce the heat generation of the battery monomer, and improve the fast charging performance and use reliability of the battery monomer; the size of the second protruding sub-portion is smaller relative to the size of the first protruding sub-portion along the second direction, which is beneficial to reduce the occupied space of the protruding portion and improve the energy density of the battery monomer.

[0023] In some embodiments, along the direction in which the first metal portion points to the second metal portion, the first insulating portion protrudes from the edge of the first welding mark portion away from the active material layer; and / or, along the direction in which the second metal portion points to the first metal portion, the first insulating portion protrudes from the edge of the first welding mark portion close to the active material layer.

[0024] By adopting the technical scheme of the embodiment, the first insulating portion can block burrs at the edge of the first welding mark, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0025] In some embodiments, along the second direction, opposite sides of the protruding part are flush with opposite sides of the corresponding first connecting subpart, and opposite edges of the first welding part are flush with opposite sides of the corresponding first connecting subpart.

[0026] By adopting the technical solutions of this embodiment, along the second direction, opposite sides of the protruding part are flush with opposite sides of the corresponding first connecting subpart, the structure is regular, and the manufacturing is convenient. In addition, redundancy can be reduced, space can be saved, and the energy density of the battery monomer can be improved. Along the second direction, the first welding part extends from one side of the first connecting subpart to the other side of the second connecting subpart. Along the second direction, the size of the first welding part is large, which is conducive to improving the welding area of the protruding part and the first connecting part, improving the flow area between the protruding part and the first connecting part, improving the flow capacity, reducing the heat generation of the battery monomer, and improving the fast-charging performance and use reliability of the battery monomer.

[0027] In some embodiments, along the second direction, at least one side of the opposite sides of the first insulating part protrudes from the side of the corresponding first connecting subpart.

[0028] By adopting the technical solutions of this embodiment, the first insulating part can block the sharp protrusion at the side of the first connecting subpart relatively distributed along the second direction, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0029] In some embodiments, along the direction of the first metal part pointing to the second metal part, the first insulating part protrudes from the side of the corresponding first connecting subpart away from the active material layer; and / or, along the direction of the second metal part pointing to the first metal part, the first insulating part protrudes from the side of the corresponding first connecting subpart close to the active material layer.

[0030] By adopting the technical solutions of this embodiment, the first insulating part can cover the side of the first connecting subpart close to and / or away from the active material layer, block the burr at the side of the first connecting subpart close to and / or the active material layer, and reduce the short circuit risk of the battery monomer.

[0031] In some embodiments, the number of protruding parts is multiple, the first connecting part includes multiple first connecting subparts, the multiple protruding parts are arranged at intervals along the second direction, and the multiple first connecting subparts are arranged at intervals along the second direction; the number of second connecting parts is multiple, the multiple second connecting parts are arranged at intervals along the second direction, and the first connecting subpart and the second connecting part are connected one by one.

[0032] By adopting the technical scheme of the embodiment, the plurality of protruding portions are arranged at intervals along the second direction, which is beneficial to divide the first metal portion into a plurality of regions along the second direction, and one region can correspond to one protruding portion, and the electrons in each region can be transmitted to the electrode lead-out portion through the corresponding protruding portion, so that the regional transmission of the electrons of the first metal portion can be realized, the transmission path of the electrons in each region is short to the corresponding protruding portion, which is beneficial to reduce the transmission distance of the electrons, reduce the overall resistance of the first pole piece, and improve the fast-charging performance and use reliability of the battery monomer.

[0033] In some embodiments, the two adjacent first insulating portions are arranged to be disconnected or connected.

[0034] By adopting the technical scheme of the embodiment, the two adjacent first insulating portions are arranged at intervals, which can save space and is beneficial to improve the energy density of the battery monomer; the two adjacent first insulating portions can be directly connected to form an integral structure, which facilitates the installation of the first insulating portion; at the same time, the first insulating portion can also cover the opposite two side surfaces of the first connecting sub-portion along the second direction, block the pointed protrusions at the opposite two side surfaces of the first connecting sub-portion along the second direction, improve the short-circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0035] In some embodiments, the second metal portion includes a transition portion and at least one protruding portion, the transition portion being connected between the protruding portion and the first metal portion; along the second direction, the size of the transition portion is greater than the sum of the sizes of all the protruding portions, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0036] By adopting the technical scheme of the embodiment, the size of the transition portion along the second direction is large, so that the transition portion can have a larger area connected with the first connecting portion, so that the electrons of the first metal portion and the active material layer can flow to the first connecting portion directly through the transition portion, the flow pressure between the protruding portion and the transition portion is reduced, the heat generation at the connection between the protruding portion and the transition portion is reduced, and the fast-charging performance of the battery monomer is improved.

[0037] In some embodiments, along the second direction, the size of the first metal portion is L1, the size of the transition portion is L2, and 0.8≤L2 / L1≤1.

[0038] By adopting the technical scheme of the embodiment, the design of 0.8≤L2 / L1≤1 makes the size of the transition portion along the second direction large, which is beneficial to increase the connection area between the first connecting portion and the transition portion, improve the flow capacity at the connection between the first connecting portion and the transition portion, improve the flow capacity of the first pole piece, reduce the heat generation of the battery monomer, and improve the fast-charging performance of the battery monomer.

[0039] In some embodiments, the first welding mark includes a second welding mark portion, the first connecting portion includes a second connecting sub-portion connected with the second connecting portion, and the second connecting sub-portion is welded to the transition portion and forms the second welding mark portion.

[0040] By adopting the technical scheme in the embodiment, the surface of the transition portion away from the insulating base is welded to the first connecting portion, so that part of the current can directly flow into or out of the first connecting portion through the transition portion, the overcurrent pressure between the protruding portion and the transition portion is reduced, the heat generation at the connection between the protruding portion and the transition portion is reduced, and the fast-charging performance of the battery monomer is improved.

[0041] In some embodiments, in the second direction, the size of the transition portion is L2, the size of the second welding mark portion is L3, and 0.8≤L3 / L2≤1.

[0042] By adopting the technical scheme in the embodiment, the design of 0.8≤L3 / L2≤1 makes the size of the second welding mark portion in the second direction larger, which is beneficial to increase the connection area between the second connecting sub-portion and the transition portion, improve the overcurrent capacity at the connection between the second connecting sub-portion and the transition portion, improve the overcurrent capacity of the first pole piece, reduce the heat generation of the battery monomer, and improve the fast-charging performance of the battery monomer.

[0043] In some embodiments, the side surface of the transition portion away from the first metal portion, the edge of the second welding mark portion away from the active material layer, and the side surface of the second connecting sub-portion away from the active material layer are flush.

[0044] By adopting the technical scheme in the embodiment, the second welding mark portion, the second connecting sub-portion, and the transition portion have regular structures, which are convenient to process and manufacture, and in addition, the redundancy of the second connecting sub-portion and the transition portion can be reduced, the space is saved, and the energy density of the battery monomer is improved.

[0045] In some embodiments, the first insulating piece includes a second insulating portion, and the second insulating portion covers at least part of the second welding mark portion.

[0046] By adopting the technical scheme in the embodiment, the second insulating portion can block burrs on the second welding mark portion, reduce the short circuit risk of the battery monomer, and is beneficial to improve the use reliability of the battery monomer.

[0047] In some embodiments, in the direction of the first metal portion pointing to the second metal portion, the second insulating portion protrudes from the edge of the second welding mark portion away from the active material layer; and / or, in the direction of the second metal portion pointing to the first metal portion, the second insulating portion protrudes from the edge of the second welding mark portion close to the active material layer.

[0048] By adopting the technical scheme in the embodiment, the second insulating portion can block burrs at the edges of the second welding mark portion relatively distributed in the first direction, reduce the short circuit risk of the battery monomer, and is beneficial to improve the use reliability of the battery monomer.

[0049] In some embodiments, the second insulating portion protrudes from a side of the second connecting sub-portion away from the active material layer in a direction from the first metal portion to the second metal portion.

[0050] By adopting the technical solutions of this embodiment, the second insulating portion can block burrs, metal debris and other components at the side of the second connecting sub-portion away from the active material layer, reduce the risk of short circuit of the battery monomer, and help improve the use reliability of the battery monomer.

[0051] In some embodiments, in the second direction, opposite sides of the transition portion are flush with opposite sides of the second connecting sub-portion, and opposite edges of the second welding mark portion are flush with opposite sides of the second connecting sub-portion.

[0052] By adopting the technical solutions of this embodiment, the edge portion structure of the first pole piece is regular in the second direction, which facilitates the processing and manufacturing of the first pole piece, reduces the redundancy of the second connecting sub-portion and the transition portion, saves space, and improves the energy density of the battery monomer. In addition, in the second direction, the size of the second welding mark portion is equal to the size of the transition portion, the first welding mark portion extends from one side of the transition portion to the other side in the second direction, and the welding area between the transition portion and the first connecting sub-portion is large, which helps improve the overcurrent capacity of the first pole piece and improve the fast charging performance of the battery monomer.

[0053] In some embodiments, in the second direction, at least one of the opposite sides of the second insulating portion protrudes from the corresponding side of the second connecting sub-portion.

[0054] By adopting the technical solutions of this embodiment, the second insulating portion can block burrs at the side of the second connecting sub-portion in the second direction, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0055] In some embodiments, in a direction from the first metal portion to the second metal portion, the second insulating portion protrudes from a side of the second connecting sub-portion away from the active material layer; and / or, in a direction from the second metal portion to the first metal portion, the second insulating portion protrudes from a side of the second connecting sub-portion toward the active material layer.

[0056] By adopting the technical solutions of this embodiment, the second insulating portion blocks burrs at the sides of the second connecting sub-portion distributed in the first direction, which helps reduce the risk of short circuit of the battery monomer and improve the use reliability of the battery monomer.

[0057] In some embodiments, the first connecting part includes at least one first connecting sub-part, the first connecting sub-part is connected between the second connecting part and the second connecting sub-part, the first connecting sub-part covers the surface of the protruding part away from the insulating base, and the first connecting sub-part corresponds to the protruding part one by one; the first insulating piece includes at least one first insulating part, the first insulating part is connected with the second insulating part, the first insulating part covers the surface of the first connecting sub-part away from the protruding part, and the first insulating part corresponds to the first connecting sub-part one by one.

[0058] By adopting the technical scheme of the embodiment, the first insulating part covers the first connecting sub-part, the second insulating part covers the second connecting sub-part, the first insulating part covers the first connecting sub-part and the second connecting sub-part, the covering area of the first insulating piece is large, the insulation effect of the first insulating piece is good, the short circuit risk of the battery monomer is reduced, and the use reliability of the battery monomer is improved.

[0059] In some embodiments, the number of protruding parts is multiple, and the multiple protruding parts are arranged at intervals along the second direction; the number of first connecting sub-parts is multiple, and the multiple first connecting sub-parts are arranged at intervals along the second direction; the number of second connecting parts is multiple, and the multiple second connecting parts are arranged at intervals along the second direction; the first connecting sub-part is connected one by one with the second connecting part; and the multiple first connecting sub-parts are connected to the side of the second connecting sub-part away from the active material layer.

[0060] By adopting the technical scheme of the embodiment, the second connecting sub-part is continuously arranged along the second direction, the multiple first connecting sub-parts can be connected as a whole, the second connecting sub-part can play a good supporting role on the first connecting sub-part, the risk of the first connecting sub-part bending and being inserted between the first pole piece and the second pole piece can be reduced, the short circuit risk of the battery monomer is reduced, and the use reliability of the battery monomer is improved; in addition, along the second direction, the size of the second connecting sub-part is large, which is conducive to improving the welding area between the second connecting sub-part and the transition part, improving the overcurrent capacity of the connection between the first connecting part and the transition part, improving the overcurrent capacity of the first pole piece, and improving the fast charging performance and use reliability of the battery monomer.

[0061] In some embodiments, the electrode assembly further includes a second pole piece opposite in polarity to the first pole piece, the second pole piece includes a main functional part arranged along a first direction and a tab part, the main functional part has a first end face close to the end of the second metal part, and the tab part extends outward from the first end face; along the direction of the first metal part towards the second metal part, the side of the second connecting sub-part away from the active material layer does not protrude the first end face; or, along the thickness direction of the current collector, the projection of the first end face is located within the projection of the second connecting sub-part.

[0062] By adopting the technical scheme of the embodiment, the side of the second connecting sub away from the active material layer is not protruded from the first end face, the first end face is arranged opposite to the hollowed area of the conductive member, the risk of short circuit of the battery monomer can be reduced, and the use reliability of the battery monomer is improved; the projection of the first end face is located in the projection of the second connecting sub along the thickness direction of the current collector, the side of the second connecting sub away from the active material layer is not arranged opposite to the main functional part, the risk of short circuit of the battery monomer can be reduced, and the use reliability of the battery monomer is improved.

[0063] In some embodiments, along a direction in which the first metal part points to the second metal part, the first insulating piece protrudes from a side of the first connecting part away from the active material layer; and / or, along a direction in which the second metal part points to the first metal part, the first insulating piece protrudes from a side of the first connecting part close to the active material layer.

[0064] By adopting the technical scheme of the embodiment, the first insulating piece can cover the side of the first connecting part relatively distributed along the first direction, and can block burrs, metal scraps and other components at the side of the first connecting part relatively distributed along the first direction, so as to reduce the risk of short circuit of the battery monomer and improve the use reliability of the battery monomer.

[0065] In some embodiments, along the first direction, the first welding mark is arranged to be spaced apart from the active material layer.

[0066] By adopting the technical scheme of the embodiment, a gap exists between the first welding mark and the active material layer, so that the welding of the first connecting part and the metal layer will not be welded to the active material layer, the risk of virtual welding of the first connecting part and the metal layer is reduced, and the use reliability of the battery monomer is improved.

[0067] In some embodiments, the electrode assembly further comprises a second insulating piece, the second insulating piece covers the surface of the second metal part away from the insulating base, and the second insulating piece is located between the first welding mark and the active material layer.

[0068] By adopting the technical scheme of the embodiment, the second insulating piece covers the part of the metal layer between the first welding mark and the active material layer, so as to realize the insulation of this part, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0069] In some embodiments, along the first direction, the first connecting part is arranged to be spaced apart from the active material layer.

[0070] By adopting the technical scheme of the embodiment, the first connecting part is not in contact with the active material layer, the mutual influence between the two can be reduced, and the performance of the battery monomer is improved.

[0071] In some embodiments, at least part of the second insulating piece is located between the first connecting part and the active material layer.

[0072] By adopting the technical scheme of this embodiment, the second insulating member covers the part of the second metal part between the connecting part and the active material layer, and the second insulating member can support this part, thereby reducing the risk of cracks in this part. In addition, the second insulating member covers the part of the second metal part between the first connecting part and the active material layer, and can also achieve the insulation of this part, thereby reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0073] In some embodiments, the electrode assembly further includes a second tab opposite in polarity to the first tab, the second tab including a main functional part arranged along the first direction and a tab part, the main functional part having a first end face near an end of the second metal part, and the tab part extending outward from the first end face; in the thickness direction of the current collector, a projection of the first end face is located within a projection of the second insulating member.

[0074] In some embodiments, along the first direction, one side of the first insulating member covers the first welding mark, and the other side of the first insulating member covers at least part of the second insulating member.

[0075] By adopting the technical scheme of this embodiment, the first insulating member and the second insulating member can achieve double-layer insulation, thereby reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0076] In some embodiments, the second insulating member includes a first phase change heat storage layer, and the first phase change heat storage layer covers a surface of the second metal part away from the insulating base.

[0077] By adopting the technical scheme of this embodiment, in the charging and discharging process of the battery monomer, the first phase change heat storage layer can absorb the heat of the second metal part, thereby reducing the temperature of the second metal part, reducing the risk of cracks and fractures of the second metal part, and being conducive to improving the electron transport capacity of the second metal part and improving the fast charging performance and use reliability of the battery monomer.

[0078] In some embodiments, the material of the first phase change heat storage layer includes at least one of an organic heat storage material and an inorganic heat storage material.

[0079] By adopting the technical scheme of this embodiment, the first phase change heat storage layer is made of an organic heat storage material, and the organic heat storage material has good cycle stability and good thermal stability, which is conducive to maintaining the stable structure of the second insulating member, improving the stability of the second insulating member fixed on the second metal part, reducing the risk of falling off of the second insulating member, and improving the use reliability of the battery monomer. The first phase change heat storage layer is made of an inorganic heat storage material, and the inorganic heat storage material has strong heat storage capacity, which is conducive to reducing the temperature of the second metal part, improving the use reliability of the battery monomer, and in addition, the inorganic heat storage material has low cost, which is conducive to reducing the manufacturing cost of the battery monomer.

[0080] In some embodiments, the material of the first phase-change heat storage layer comprises an organic heat storage material, and the organic heat storage material comprises at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

[0081] By adopting the technical scheme of this embodiment, the organic heat storage material adopts the above material, and in the charging and discharging process of the battery monomer, the first phase-change heat storage layer can better absorb the heat of the second metal part, reduce the temperature of the second metal part, and improve the use reliability of the battery monomer. In addition, the first phase-change heat storage layer can also maintain a stable structural form, reduce the risk of falling off of the second insulating piece, and is conducive to improving the use reliability of the battery monomer.

[0082] In some embodiments, the material of the first phase-change heat storage layer comprises an inorganic heat storage material, and the inorganic heat storage material comprises at least one of a nitrate, a carbonate, a fluoride, and a hydrochloride.

[0083] By adopting the technical scheme of this embodiment, the inorganic heat storage material adopts the above material, and in the charging and discharging process of the battery monomer, the first phase-change heat storage layer can better absorb the heat of the second metal part, reduce the temperature of the second metal part, and improve the use reliability of the battery monomer. In addition, the first phase-change heat storage layer can also maintain a stable structural form, reduce the risk of falling off of the second insulating piece, and is conducive to improving the use reliability of the battery monomer.

[0084] In some embodiments, along the first direction, one side of the first insulating piece covers the first solder print, and the other side of the first insulating piece covers the active material layer.

[0085] By adopting the technical scheme of this embodiment, the first insulating piece extends from the first solder print to the active material layer, the coverage area of the first insulating piece is wide, and the insulation effect is good, which is conducive to improving the use reliability of the battery monomer.

[0086] In some embodiments, the number of metal layers is two, the two metal layers cover opposite sides of the insulating base along the thickness direction of the current collector, the number of active material layers is two, the two active material layers cover the first metal parts of the two metal layers respectively, the number of conductive members is two, the first connection parts of the two conductive members are respectively soldered to the second metal parts of the two metal layers and form two first solder prints, and the number of first insulating pieces is two, the two first insulating pieces cover the two first solder prints respectively.

[0087] By adopting the technical scheme of this embodiment, the first connection parts of the two conductive members are respectively soldered to the metal layers located on opposite sides of the insulating base, so that the second connection parts of the two conductive members are connected, thereby electrically connecting the two metal layers, breaking the insulation limitation of the insulating base, effectively improving the conductive capacity of the first pole piece, improving the fast-charging performance of the battery monomer, reducing the heating risk of the battery monomer, and improving the use reliability of the battery monomer.

[0088] In some embodiments, the part of the first insulating piece protruding from the metal layer forms a blocking part in a direction from the first metal part to the second metal part, and the blocking part is located at a side of the second connecting part in a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0089] By adopting the technical scheme in the embodiments, the blocking part can block burrs, metal debris and other components at the edge of the metal layer, thereby reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0090] In some embodiments, the blocking parts of the two first insulating pieces are in abutment.

[0091] By adopting the technical scheme in the embodiments, the blocking parts of the two first insulating pieces can wrap burrs, metal debris and other components at the edge of the metal layer after abutment, thereby reducing the falling risk of the metal debris, reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0092] In some embodiments, the second connecting parts of the two conductive members are welded and form a second welding mark.

[0093] By adopting the technical scheme in the embodiments, the welding of the second connecting parts of the two conductive members can electrically connect the metal layers located on opposite sides of the insulating base, thereby breaking the insulation limitation of the insulating base, effectively improving the conductive capacity of the first pole piece, improving the fast charging performance of the battery monomer, reducing the heat generation of the battery monomer and improving the use reliability of the battery monomer.

[0094] In some embodiments, the first insulating piece covers at least part of the second welding mark.

[0095] By adopting the technical scheme in the embodiments, the first insulating piece can cover the second welding mark, block burrs, metal debris and other components on the second welding mark, reduce the short circuit risk of the battery monomer and improve the use reliability of the battery monomer.

[0096] In some embodiments, in a direction from the first metal part to the second metal part, the first insulating piece protrudes from the second welding mark away from the edge of the active material layer.

[0097] By adopting the technical scheme in the embodiments, the first insulating piece can cover the entire second welding mark, block burrs, metal debris and other components on the second welding mark, reduce the short circuit risk of the battery monomer and improve the use reliability of the battery monomer.

[0098] In some embodiments, the electrode assembly further includes a second tab opposite to the first tab in polarity, the second tab including a main functional portion arranged along the first direction and a tab portion, the main functional portion having a first end face close to an end of the second metal portion, and the tab portion extending outwardly from the first end face; and in the thickness direction of the current collector, a projection of the first end face is located within a projection of the first insulating member.

[0099] By adopting the technical scheme of this embodiment, the first insulating member can block the sharp protrusion at the first end face, reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0100] In some embodiments, the glass transition temperature of the first insulating member is greater than or equal to 150℃, and optionally, the glass transition temperature of the first insulating member is greater than or equal to 200℃.

[0101] By adopting the technical scheme of this embodiment, in the charging and discharging process of the battery monomer, the first insulating member can maintain a stable structure form, reducing the risk of melting of the first insulating member, reducing the exposure risk of burrs, metal debris and other components on the first weld mark, reducing the short circuit risk of the battery monomer, and improving the use reliability of the battery monomer.

[0102] In some embodiments, the specific heat capacity of the first insulating member is greater than or equal to 1.2 J / g·℃.

[0103] By adopting the technical scheme of this embodiment, the design of the specific heat capacity of the first insulating member being greater than or equal to 1.2 J / g·℃ makes the first insulating member absorb heat at the first weld mark in the charging and discharging process of the battery monomer, reducing the temperature of the first weld mark, and the temperature rise of the first insulating member is small, reducing the risk of melting of the first insulating member, and the first insulating member can stably block the burrs of the first weld mark, reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0104] In some embodiments, the first insulating member includes a first insulating base layer and a first adhesive layer, the first adhesive layer being bonded between the first weld mark and the first insulating base layer.

[0105] By adopting the technical scheme of the embodiment, the first insulating piece adopts the structural form of the adhesive tape, the first insulating piece can be directly attached to the first welding mark, and the risk of missing coverage is reduced; the first insulating base layer and the first adhesive layer cover the first welding mark and block the burrs of the first welding mark, the thickness of the first insulating base layer and the thickness of the first adhesive layer do not need to be set to be large, which is beneficial to improve the energy density of the battery monomer; the first insulating base layer has good structural strength and can stably block the burrs of the first welding mark, thereby improving the use reliability of the battery monomer; the first adhesive layer can stably fix the first insulating base layer on the first welding mark, thereby reducing the risk of falling off of the first insulating piece; the metal debris of the first welding mark can also be adhered to the first adhesive layer, which can effectively reduce the risk of falling of the metal debris of the first welding mark and reduce the short circuit risk of the battery monomer.

[0106] In some embodiments, the first insulating piece further comprises a second phase change heat storage layer, the second phase change heat storage layer is connected between the first insulating base layer and the first adhesive layer, and the first adhesive layer is adhered between the second phase change heat storage layer and the first welding mark.

[0107] By adopting the technical scheme of the embodiment, the second phase change heat storage layer can absorb heat at the first welding mark during the phase change process, reduce the temperature rise of the first insulating base layer and the first adhesive layer, reduce the risk of melting of the first insulating base layer and the first adhesive layer, and be beneficial to maintaining the structural stability of the first insulating piece and improving the use reliability of the battery monomer.

[0108] In some embodiments, the material of the second phase change heat storage layer comprises at least one of an organic heat storage material and an inorganic heat storage material.

[0109] By adopting the technical scheme of the embodiment, the second phase change heat storage layer is made of an organic heat storage material, the cyclic stability and thermal stability of the organic heat storage material are good, which is beneficial to maintaining the stable structure of the first insulating piece, improving the stability of the first insulating piece fixed on the first welding mark, reducing the risk of falling off of the first insulating piece, and improving the use reliability of the battery monomer; the second phase change heat storage layer is made of an inorganic heat storage material, the heat storage capacity of the inorganic heat storage material is strong, which is beneficial to reducing the temperature at the first welding mark and improving the use reliability of the battery monomer, in addition, the cost of the inorganic heat storage material is low, which is beneficial to reducing the manufacturing cost of the battery monomer.

[0110] In some embodiments, the material of the second phase change heat storage layer comprises an organic heat storage material, and the organic heat storage material comprises at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

[0111] By adopting the technical scheme of the embodiment, the organic heat storage material adopts the above material, in the charging and discharging process of the battery monomer, the second phase change heat storage layer can better absorb the heat of the first welding mark, reduce the temperature rise of the first insulating base layer and the first adhesive layer, help the first insulating base layer to maintain a stable structure form, can stably block the burrs, metal debris and other components on the first welding mark, reduce the risk of falling of the first insulating part, and improve the use reliability of the battery monomer.

[0112] In some embodiments, the material of the second phase change heat storage layer includes an inorganic heat storage material, and the inorganic heat storage material includes at least one of nitrate, carbonate, fluoride and hydrochloride.

[0113] By adopting the technical scheme of the embodiment, the inorganic heat storage material adopts the above material, in the charging and discharging process of the battery monomer, the second phase change heat storage layer can better absorb the heat of the first welding mark, reduce the temperature rise of the first insulating base layer and the first adhesive layer, help the first insulating base layer to maintain a stable structure form, can stably block the burrs, metal debris and other components on the first welding mark, reduce the risk of falling of the first insulating part, and improve the use reliability of the battery monomer.

[0114] In some embodiments, the layer thickness of the second phase change heat storage layer ranges from 1 μm to 5 μm.

[0115] By adopting the technical scheme of the embodiment, the design that the layer thickness of the second phase change heat storage layer is greater than or equal to 1 μm makes the second phase change heat storage layer able to absorb the heat of the first welding mark, reduce the temperature of the first welding mark, help maintain the mechanical strength and structural stability of the first insulating part, and improve the use reliability of the battery monomer; the design that the layer thickness of the second phase change heat storage layer is less than or equal to 5 μm is beneficial to reducing the occupied space and weight of the phase change heat storage, and is beneficial to improving the energy density of the battery monomer.

[0116] In some embodiments, the glass transition temperature of the first adhesive layer is greater than the phase change temperature of the second phase change heat storage layer, and / or the glass transition temperature of the first insulating base layer is greater than the phase change temperature of the second phase change heat storage layer.

[0117] By adopting the technical scheme of the embodiment, in the case that the second phase change heat storage layer absorbs heat and changes phase, the first insulating part can maintain a stable structure form, which is beneficial to maintaining the mechanical strength and structural stability of the first insulating part, reducing the risk of insulation failure of the first insulating part, and improving the use reliability of the battery monomer.

[0118] In some embodiments, the material of the first insulating base layer includes at least one of polypropylene, polyethylene terephthalate, aramid 1313, polyvinylidene fluoride and cellulose.

[0119] By adopting the technical scheme of the embodiment, the first insulating base layer adopts the above material, and in the charging and discharging process of the battery monomer, the first insulating base layer can maintain a stable structure form and is not prone to melting, the first insulating piece has good high-temperature resistance, and the use reliability of the battery monomer is improved.

[0120] In some embodiments, the material of the first adhesive layer includes at least one of acrylic, ethylene acrylic copolymer, rubber, and latex.

[0121] By adopting the technical scheme of the embodiment, the first adhesive layer adopts the above material, and in the charging and discharging process of the battery monomer, the first adhesive layer can maintain a stable structure form and is not prone to melting, the first insulating piece can be stably bonded to the first welding mark, the risk of falling off of the first insulating piece is reduced, and the use reliability of the battery monomer is improved.

[0122] In some embodiments, the thickness of the first adhesive layer ranges from 1 to 7 microns.

[0123] By adopting the technical scheme of the embodiment, the thickness of the first adhesive layer is greater than or equal to 1 micron, which enables the first adhesive layer to stably bond the second phase change heat storage layer and the first welding mark together, reduces the risk of falling off of the first insulating piece, and improves the use reliability of the battery monomer; and the thickness of the first adhesive layer is less than or equal to 7 microns, which reduces the risk of overflow of the first adhesive layer.

[0124] In some embodiments, the thickness of the first insulating base layer ranges from 1 to 10 microns.

[0125] By adopting the technical scheme of the embodiment, the thickness of the first insulating base layer is greater than or equal to 1 micron, which enables the first insulating base layer to better block burrs of the first welding mark and improve the use reliability of the battery monomer; and the thickness of the first insulating base layer is less than or equal to 10 microns, which reduces the occupied space and weight of the first insulating base layer and improves the energy density of the battery monomer.

[0126] In some embodiments, the current collector further includes a conductive protective layer, at least part of the conductive protective layer is located between the active material layer and the first metal part.

[0127] By adopting the technical scheme of the embodiment, the conductive protective layer can separate the active material layer and the metal layer, protect the metal layer, reduce the risk of cracks of the metal layer caused by rolling the active material layer, and improve the current-carrying capacity of the metal layer.

[0128] In some embodiments, along a direction of the first metal part towards the second metal part, the conductive protective layer protrudes from an end of the active material layer close to the second metal part.

[0129] By adopting the technical scheme of the embodiment, the conductive protective layer can completely separate the active material layer and the metal layer, the conductive protective layer has better protection capability for the metal layer, the overcurrent capacity of the first pole piece is better, and the fast charging performance and use reliability of the battery monomer are improved.

[0130] In some embodiments, the thickness of the first metal part is less than the thickness of the second metal part at least in part.

[0131] By adopting the technical scheme of the embodiment, the thickness of the second metal part can be greater than the thickness of the first metal part at least in part, the thickness of the second metal part is large, the overcurrent capacity of the second metal part is improved, the heat generation of the second metal part is reduced, the melting risk of the first insulating part is reduced, the use reliability of the battery monomer is improved, in addition, the overcurrent capacity of the second metal part is also improved, which is also conducive to improving the fast charging performance of the battery monomer.

[0132] In some embodiments, the first metal part includes a first subpart and a second subpart, the first subpart is connected between the second subpart and the second metal part, the first subpart and the second subpart are covered with the active material layer, the thickness of the first subpart is greater than the thickness of the second subpart, and the thickness of the second metal part is greater than or equal to the thickness of the first subpart.

[0133] By adopting the technical scheme of the embodiment, the thickness of the first subpart is greater than the thickness of the second subpart, so that the overcurrent capacity of the first subpart is greater than the overcurrent capacity of the second subpart, which can reduce the limitation on the current, improve the overcurrent capacity of the first pole piece, reduce the heat generation of the battery monomer, and be conducive to improving the use reliability of the battery monomer.

[0134] In some embodiments, the current collector further includes a conductive protective layer, the conductive protective layer includes a first protective part and a second protective part, the first protective part is located between the first subpart and the active material layer, and the second protective part is located between the second subpart and the active material layer; wherein the thickness of the first protective part is less than the thickness of the second protective part.

[0135] By adopting the technical scheme of the embodiment, the surface of the conductive protective layer away from the insulating base approaches a plane, which is conducive to reducing the roll damage and improving the overcurrent capacity of the metal layer; in addition, the winding bulging problem of the current collector can also be reduced.

[0136] In some embodiments, the conductive protective layer further includes a third protective part, the third protective part covers the surface of the second metal part away from the insulating base, and the thickness of the third protective part is less than or equal to the thickness of the first protective part.

[0137] By adopting the technical scheme of the embodiment, the third protection part is arranged, so that the conductive protection layer protrudes from the active material layer, the active material layer and the metal layer can be better separated, in addition, the thickness of the third protection part is not too large, which is beneficial to reduce the waste of materials and save the manufacturing cost of the battery monomer.

[0138] In a second aspect, a battery device is provided, which includes the battery monomer of the above embodiment.

[0139] The battery device of the embodiment of the application adopts the battery monomer described above, and the use reliability of the battery monomer is good, and the use reliability of the battery device is good.

[0140] In a third aspect, a battery device is provided, which includes the battery monomer of the above embodiment.

[0141] The electric device of the embodiment of the application adopts the battery device described above, and the use reliability of the battery device is good, which is beneficial to improve the use reliability of the electric device.

[0142] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, the specific embodiments of the application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following will specifically describe the embodiments of the application. BRIEF DESCRIPTION OF DRAWINGS

[0143] In order to more clearly illustrate the technical scheme in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0144] Fig. 1 is a structural schematic view of a vehicle provided by some embodiments of the application.

[0145] Fig. 2 is an exploded schematic view of a battery device provided by some embodiments of the application.

[0146] Fig. 3 is an exploded schematic view of a battery monomer provided by some embodiments of the application.

[0147] Fig. 4 is a structural schematic view of an electrode assembly provided by some embodiments of the application.

[0148] Fig. 5 is a sectional view along line A-A in Fig. 4.

[0149] Fig. 6 is a structural schematic view of a first pole piece, a first insulating piece and a second insulating piece provided by some embodiments of the application.

[0150] Fig. 7 is a sectional view along line B-B in Fig. 6.

[0151] Fig. 8 is a structural schematic view of the first pole piece and the second insulating member according to some embodiments of the present application.

[0152] Fig. 9 is an enlarged view of a portion of Fig. 8 at C.

[0153] Fig. 10 is a structural schematic view of the first pole piece hiding the second insulating member and the conductive member according to some embodiments of the present application.

[0154] Fig. 11 is an enlarged view of a portion of Fig. 10 at D.

[0155] Fig. 12 is a structural schematic view of the first pole piece, the first insulating member and the second insulating member according to some embodiments of the present application.

[0156] Fig. 13 is a structural schematic view of the first pole piece and the second insulating member according to some embodiments of the present application.

[0157] Fig. 14 is an enlarged view of a portion of Fig. 13 at F.

[0158] Fig. 15 is a structural schematic view of the first pole piece hiding the conductive member according to some embodiments of the present application.

[0159] Fig. 16 is an enlarged view of a portion of Fig. 15 at G.

[0160] Fig. 17 is a sectional view of the first pole piece, the first insulating member and the second insulating member along line B-B of Fig. 6 according to some embodiments of the present application.

[0161] Fig. 18 is a sectional view along line E-E of Fig. 12.

[0162] Fig. 19 is a structural schematic view of the first insulating member according to some embodiments of the present application.

[0163] Fig. 20 is a sectional view along line H-H of Fig. 19.

[0164] Fig. 21 is a sectional view of the first insulating member along line H-H of Fig. 19 according to some embodiments of the present application.

[0165] In the drawings:

[0166] 1000, vehicle; 1100, battery device; 1200, controller; 1300, motor; 100, battery cell; 101, electrode assembly; 1, first tab; 10, current collector; 11, insulating base body; 12, metal layer; 121, first metal portion; 1211, first sub-portion; 1212, second sub-portion; 122, second metal portion; 1221, transition portion; 1222, protruding portion; 12221, first protruding sub-portion; 12222, second protruding sub-portion; 13, conductive protective layer; 131, first protective portion; 132, second protective portion; 133, third protective portion; 20, active material layer; 30, conductive member; 31, first connecting portion; 311, first connecting sub-portion; 312, second connecting sub-portion; 32, second connecting portion; 41, first insulating member; 4111, first insulating base layer; 4112, first adhesive layer; 4113, second phase change heat storage layer; 4121, first insulating portion; 4122, second insulating portion; 4131, barrier portion; 42, second insulating member; 51, first solder print; 511, first solder print portion; 5111, first solder print sub-portion; 5112, second solder print sub-portion; 512, second solder print portion; 52, second solder print; 2, second tab; 210, main body functional portion; 2101, first end surface; 220, tab portion; 3, spacer; 200, housing; 201, end cap; 2011, electrode lead-out portion; 202, case; 300, box body; 301, first box body portion; 302, second box body portion. DETAILED DESCRIPTION

[0167] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application and not intended to limit the present application.

[0168] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the present specification and claims and the aforementioned description of the drawings herein, the terms "comprising" and "having" and any variations thereof, are intended to cover not exclusively inclusive.

[0169] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features.

[0170] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are an "or" relationship.

[0171] In the description of the embodiments of the present application, the term "a plurality of" refers to two or more (including two), and similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces). The meaning of "several" is one or more, unless otherwise explicitly specified.

[0172] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0173] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0174] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0175] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging of the battery cell.

[0176] The battery cell can include, but is not limited to, a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, and the like.

[0177] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, or other shaped battery cell, the prismatic battery cell including a square-shaped battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, such as a hexagonal prismatic battery cell, and the like.

[0178] The battery device referred to in embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0179] In some embodiments, the battery device can be a battery module, when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0180] In some embodiments, the battery device can be a battery pack, the battery pack including a box and battery cells, the battery cells or battery modules being contained in the box.

[0181] In some embodiments, the box can be part of the chassis structure of the vehicle. For example, part of the box can be at least part of the floor of the vehicle, or part of the box can be at least part of the cross beam and longitudinal beam of the vehicle.

[0182] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, and the like.

[0183] The battery cell generally includes an electrode assembly and a case, the electrode assembly being contained in the case. The electrode assembly includes a positive electrode and a negative electrode. During charging and discharging of the battery cell, active ions (such as lithium ions) are inserted and extracted between the positive electrode and the negative electrode.

[0184] In some embodiments, the electrode assembly further includes a separator, the separator being disposed between the positive electrode and the negative electrode, and can prevent the positive electrode and the negative electrode from short-circuiting while allowing the active ions to pass through.

[0185] The case is used to encapsulate the electrode assembly and other components such as electrolyte. The case can be a steel case, an aluminum case, a plastic case (such as polypropylene), a composite metal case (such as a copper-aluminum composite case), or an aluminum-plastic film, and the like.

[0186] In some embodiments, the positive electrode can be a positive electrode sheet, the positive electrode sheet can include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The negative electrode can be a negative electrode sheet, the negative electrode sheet can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0187] The current collector (positive electrode current collector or negative electrode current collector) is usually made of metal materials, such as metal aluminum foil and metal copper foil. However, the pure metal foil material is prone to generate metal burrs, and the burrs can pierce the separator to cause internal short circuit, resulting in a high risk of fire and explosion of the battery cell.

[0188] In order to reduce the risk of short circuit in the battery cell, a current collector is provided, which includes an insulating base and a metal layer covering the surface of the insulating base, and an active material layer covering the surface of the metal layer away from the insulating base. Compared with pure metal, the thickness of the metal layer is small, and the burr generated after cutting the metal layer is small, which is not easy to pierce the separator and reduce the risk of short circuit of the battery cell. The edge of the metal layer is usually welded with a conductive member and electrically connected with the electrode lead-out part of the battery cell through the conductive member, so as to realize the input or output of the electric energy of the battery cell. The conductive member and the metal layer are welded to form a welding mark, and the burr is easy to generate, which has the risk of piercing the separator to cause short circuit of the battery cell, affecting the use reliability of the battery cell.

[0189] Based on this, the embodiment of the present application provides a technical scheme, the metal layer of the battery cell is welded with the conductive member to form a first welding mark, and at least part of the first welding mark is covered with a first insulating member. The first insulating member is used to block the burr on the first welding mark, thereby reducing the risk of short circuit of the battery cell and improving the use reliability of the battery cell.

[0190] The battery cell described in the embodiment of the present application is suitable for a battery device and a power utilization device using the battery device.

[0191] The battery device disclosed in the embodiment of the present application can be used in a power utilization device using the battery device as a power supply or a variety of energy storage systems using the battery device as an energy storage element. The power utilization device can be, but is not limited to, a mobile phone, a tablet computer, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, etc. The electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0192] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0193] As shown in FIG. 1, the inside of the vehicle 1000 is provided with a battery device 1100, which can be arranged at the bottom, the head or the tail of the vehicle 1000. The battery device 1100 can be used for power supply of the vehicle 1000, for example, the battery device 1100 can be used as an operating power supply of the vehicle 1000.

[0194] The vehicle 1000 can further include a controller 1200 and a motor 1300, the controller 1200 being configured to control the battery device 1100 to supply power to the motor 1300, for example, for power requirements of the vehicle 1000 during start-up, navigation, and travel.

[0195] In some embodiments of the present application, the battery device 1100 can not only serve as a power source for the operation of the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000. FIG. 2 is an exploded view of the battery device 1100 according to some embodiments of the present application. As shown in FIG. 2, the battery device 1100 includes a box 300 and battery cells, the battery cells being accommodated in the box 300.

[0196] The box 300 is configured to accommodate the battery cells, and the box 300 can have various structures. In some embodiments, the box 300 can include a first box part 301 and a second box part 302, the first box part 301 and the second box part 302 being coupled to each other to define a space for accommodating the battery cells. The second box part 302 can be a hollow structure with one end open, and the first box part 301 can be a plate structure, the first box part 301 being coupled to the open end of the second box part 302 to form the box 300 with the space for accommodating the battery cells. Alternatively, the first box part 301 and the second box part 302 can each be a hollow structure with one side open, the open side of the first box part 301 being coupled to the open side of the second box part 302 to form the box 300 with the space for accommodating the battery cells. Of course, the first box part 301 and the second box part 302 can have various shapes, such as a cylinder or a cuboid.

[0197] To improve the sealing performance of the first box part 301 and the second box part 302 after being coupled, a sealing member, such as a sealant or a sealing ring, can be provided between the first box part 301 and the second box part 302.

[0198] Suppose the first box part 301 is coupled to the top of the second box part 302, the first box part 301 can also be referred to as an upper box cover, and the second box part 302 can also be referred to as a lower box 300.

[0199] In the battery device 1100, the battery cells can be one or multiple. If the battery cells are multiple, the multiple battery cells can be connected in series, in parallel, or in a mixed manner, the mixed manner referring to a combination of series connection and parallel connection.

[0200] The plurality of battery cells can be directly connected in series or in parallel or in a hybrid manner, and the plurality of battery cells can be accommodated in the box 300. Of course, the plurality of battery cells can be connected in series or in parallel or in a hybrid manner to form a battery module, and the plurality of battery modules can be connected in series or in parallel or in a hybrid manner to form a whole and can be accommodated in the box 300.

[0201] Exemplarily, the battery cell can be the smallest unit constituting the battery device 1100.

[0202] As shown in FIG. 3, in some embodiments, the battery cell includes a shell 200 and an electrode assembly 101 accommodated in the shell 200. The electrode assembly 101 includes a positive electrode and a negative electrode. During the charging and discharging of the battery cell, active ions (for example, lithium ions) are embedded and extracted between the positive electrode and the negative electrode. Optionally, the electrode assembly 101 further includes a separator 3 disposed between the positive electrode and the negative electrode, which can reduce the risk of short circuit between the positive electrode and the negative electrode, and at the same time, can allow the active ions to pass through.

[0203] The shell 200 is used to encapsulate the electrode assembly 101 and other components such as electrolyte.

[0204] In some embodiments, the shell 200 includes a housing 202 and an end cover 201, and the housing 202 has an opening, and the end cover 201 is used to cover the opening.

[0205] The housing 202 is a component used to cooperate with the end cover 201 to form an internal cavity of the battery cell, and the internal cavity can be used to accommodate the electrode assembly 101, electrolyte and other components.

[0206] The housing 202 and the end cover 201 can be independent components. Exemplarily, an opening can be provided on the housing 202, and the end cover 201 is used to cover the opening to form the internal cavity of the battery cell.

[0207] The housing 202 can be various shapes and various sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the housing 202 can be determined according to the specific shape and size of the electrode assembly 101. The material of the housing 202 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, aluminum plastic film, steel plastic film, etc.

[0208] The shape of the end cover 201 can be adapted to the shape of the housing 202 to cooperate with the housing 202. The material of the end cover 201 can be the same as or different from the material of the housing 202. Optionally, the end cover 201 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cover 201 is not easy to deform when subjected to extrusion and collision, so that the battery cell can have higher structural strength, and the reliability can also be improved.

[0209] The end cap 201 is connected to the housing 202 by welding, adhesion, clamping, or other means.

[0210] The housing 202 can be open at one end or at both ends. In some examples, the housing 202 can be a structure open at one side, and the end cap 201 is provided as one and covers the housing 202. In other examples, the housing 202 can also be a structure open at both sides, and the end cap 201 is provided as two, and the two end caps 201 cover the two openings of the housing 202, respectively.

[0211] In some embodiments, the battery cell includes electrode leads 2011. The number of electrode leads 2011 is two, and the two electrode leads 2011 are connected to the positive and negative electrode sheets, respectively, for outputting or inputting the electrical energy of the battery cell.

[0212] In some embodiments, the battery cell further includes an electrolyte contained in the housing 200. The electrolyte serves to conduct ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state, or a solid state.

[0213] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0214] 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 difluoro oxalate borate, lithium di-oxalate borate, lithium difluoro di-oxalate phosphate, and lithium tetrafluoro oxalate phosphate.

[0215] 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, butyrosulfone, methyl ethyl sulfone, and diethyl sulfone.

[0216] The solvent can also be an ether solvent. The ether solvent 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.

[0217] In some embodiments, the gel-state electrolyte includes a polymer as a skeleton network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0218] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0219] As an example, the polymer solid-state electrolyte can be a polyether (polyethylene oxide), a polysiloxane, a polycarbonate, a polyacrylonitrile, a polyvinylidene fluoride, a polymethyl methacrylate, a single-ion polymer, a polyionic liquid-lithium salt, a cellulose, or the like.

[0220] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfur, argyrodite), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0221] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0222] Referring to FIGS. 4 and 5, the electrode assembly 101 of the embodiments of the present application includes first and second polar plates 1 and 2 having opposite polarities.

[0223] As an example, one of the first and second polar plates 1 and 2 is a positive polar plate, and the other is a negative polar plate.

[0224] In some embodiments, the positive polar plate can include a positive current collector and a positive active material layer disposed on at least one surface of the positive current collector.

[0225] As an example, the positive current collector has two surfaces opposite in the thickness direction thereof, and the positive active material layer is disposed on either one or both of the two opposite surfaces of the positive current collector.

[0226] As an example, the positive current collector can employ carbon, a metal foil, or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, titanium, silver surface-treated aluminum, or stainless steel, or the like 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, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0227] As an example, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. The positive electrode active material can also use other conventional materials that can be used as the positive electrode active material layer of the battery device 1100. These positive electrode active materials can be used alone only one or two or more in combination. Examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which can also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (e.g., LiMnPO4), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (e.g., LiCoO2), lithium nickel oxide (e.g., LiNiO2), lithium manganese oxide (e.g., LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to simply as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (which can also be referred to simply as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (which can also be referred to simply as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (which can also be referred to simply as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (which can also be referred to simply as NCM811), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.80 Co 0.15 Al 0.05 O2), and modified compounds thereof, etc.

[0228] In some embodiments, the negative electrode tab can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0229] As an example, the negative current collector can employ a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, or the like can be employed. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, or the like. 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, or the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, or the like).

[0230] As an example, the negative active material layer includes a negative active material. 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, a silicon-based material, a tin-based material, lithium titanate, and the like. The silicon-based material can include at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can include at least one of elemental tin, a tin oxide compound, and a tin alloy. The negative active material of the present application can also use other conventional materials that can be used as a negative active material of the battery device 1100. These negative active materials can be used alone only one or two or more can be used in combination.

[0231] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0232] In some embodiments, the electrode assembly 101 further includes a separator 3 for separating the first electrode sheet 1 and the second electrode sheet 2. The separator 3 can reduce the risk of short circuit between the positive and negative electrodes while allowing the active ions to pass through.

[0233] In some embodiments, the separator 3 includes a separator film. The separator film of the present application can be selected from any known porous structure separator film having good chemical stability and mechanical stability.

[0234] As an example, the main material of the separator film can include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride, and ceramic. 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 3 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.

[0235] In some embodiments, the separator 3 is a solid electrolyte. The solid electrolyte is disposed between the positive electrode sheet and the negative electrode sheet and functions to transport ions and separate the positive and negative electrodes.

[0236] In some embodiments, the electrode assembly 101 is in a roll structure. For example, the first electrode sheet 1 and the second electrode sheet 2 are both in a strip structure, and the first electrode sheet 1, the separator 3, and the second electrode sheet 2 are wound into a roll structure.

[0237] In some embodiments, the electrode assembly 101 is in a stack structure.

[0238] For example, a plurality of first electrode sheets 1 and a plurality of second electrode sheets 2 are alternately stacked.

[0239] For example, a plurality of first electrode sheets 1 are provided, and the second electrode sheet 2 is folded to form a plurality of folded segments which are stacked, and one first electrode sheet 1 is clamped between adjacent folded segments.

[0240] For example, a plurality of first electrode sheets 1 and a plurality of second electrode sheets 2 are alternately stacked.

[0241] For example, a plurality of separators 3 are provided and arranged between any adjacent first electrode sheet 1 or second electrode sheet 2.

[0242] For example, the separators 3 are continuously provided and arranged between any adjacent first electrode sheet 1 or second electrode sheet 2 by folding or winding.

[0243] In some embodiments, the electrode assembly 101 can be in a cylindrical shape, a flat shape, or a multi-prism shape.

[0244] Referring to FIGS. 6-9, in some embodiments, the battery cell 100 includes a housing 200 and an electrode assembly 101. The housing 200 is provided with an electrode lead-out portion 2011. At least part of the electrode assembly 101 is arranged in the housing 200. The electrode assembly 101 includes a first electrode sheet 1, which includes a current collector 10, a conductive member 30, and an active material layer 20. The conductive member 30 is electrically connected to the electrode lead-out portion 2011. The current collector 10 includes an insulating base body 11 and a metal layer 12. The insulating base body 11, the metal layer 12, and the active material layer 20 are stacked in the thickness direction of the current collector 10. At least part of the metal layer 12 is located between the insulating base body 11 and the active material layer 20. The metal layer 12 includes a first metal portion 121 and a second metal portion 122 which are arranged in a first direction and connected to each other. The first direction is perpendicular to the thickness direction of the current collector 10. At least part of the first metal portion 121 is covered with the active material layer 20. At least part of the second metal portion 122 is not covered with the active material layer 20. The conductive member 30 is welded to the surface of the second metal portion 122 away from the insulating base body 11 and forms a first welding mark 51. The electrode assembly 101 includes a first insulating member 41 which covers at least part of the first welding mark 51.

[0245] Part of the electrode assembly 101 is located inside the shell 200, and the other part is located outside the shell 200; or the entire electrode assembly 101 is located inside the shell 200.

[0246] In some examples, the first pole piece 1 is a positive pole piece, the current collector 10 is a positive current collector, the positive current collector adopts a composite current collector structure, and the active material layer 20 is a positive active material layer; or the first pole piece 1 is a negative pole piece, the current collector 10 is a negative current collector, the negative current collector is a composite current collector structure, and the active material layer 20 is a negative active material layer.

[0247] The conductive member 30 can refer to a component for connecting the electrode lead-out portion 2011 and the metal layer 12, and the conductive member 30 can adopt a copper foil or an aluminum foil to improve the current carrying capacity of the conductive member 30.

[0248] The electrode lead-out portion 2011 can refer to a metal component for outputting or inputting electric energy, and the electrode lead-out portion 2011 is connected with an external electronic device to enable the battery monomer 100 to output or input electric energy; the electrode lead-out portion 2011 can also be referred to as a pole post, and the electrode lead-out portion 2011 can be arranged on the shell 202 or the end cover 201.

[0249] The electrode lead-out portion 2011 is electrically connected with the conductive member 30, and the electrode lead-out portion 2011 can be directly connected with the conductive member 30; for example, the electrode lead-out portion 2011 is directly welded on the conductive member 30; or the electrode lead-out portion 2011 can be connected with the conductive member 30 through a conductive piece (for example, a adapter sheet), for example, one end of the conductive piece is welded on the conductive member 30, and the other end of the conductive piece is welded on the electrode lead-out portion 2011.

[0250] The current collector 10 includes the metal layer 12 and the insulating base body 11, and the current collector 10 has a multilayer structure; the insulating base body 11 can refer to a component made of an insulating material (for example, the above-mentioned high polymer base material) in the current collector 10, and the metal layer 12 can refer to a component made of the above-mentioned metal material in the current collector 10.

[0251] The surface of the insulating base body 11 is covered with the metal layer 12, and the surface of the metal layer 12 away from the insulating base body 11 is covered with the active material layer 20, so that the insulating base body 11, the metal layer 12 and the active material layer 20 are arranged in a stacked manner, and the stacking direction of the insulating base body 11, the metal layer 12 and the active material layer 20 is the thickness direction of the current collector 10 (which can be referred to as the Y direction in FIG. 7). Among them, the active material layer 20 can be directly covered on the surface of the metal layer 12, or other substances (for example, the conductive protective layer 13) can be covered on the surface of the metal layer 12 before the active material layer 20 is covered.

[0252] In some examples, one surface of the insulating base body 11 is covered with the metal layer 12.

[0253] In some examples, the insulating base 11 is covered with metal layers 12 on both surfaces, and at least one of the metal layers 12 is covered with an active material layer 20 on the surface facing away from the insulating base 11.

[0254] The first direction can refer to a direction perpendicular to the thickness direction of the current collector 10, or a direction close to perpendicular to the current collector 10; the second direction can refer to a direction perpendicular to the thickness direction and the first direction of the current collector 10, or a direction close to perpendicular to the thickness direction and the first direction of the current collector 10.

[0255] In some examples, the electrode assembly 101 is in a roll structure, and when the first tab 1 is in an unfolded state, the first direction can refer to the width direction of the first tab 1 (see the Z direction in FIG. 6); the second direction can refer to the length direction of the first tab 1 (see the X direction in FIG. 6). When the first tab 1 is in a rolled state, the second direction can also refer to the rolling direction of the first tab 1 (see the direction indicated by the arrow V in FIG. 4).

[0256] In some examples, the electrode assembly 101 is in a stack structure, and the first direction can refer to the width direction of the first tab 1 (see the Z direction in FIG. 6); the second direction can refer to the length direction of the first tab 1 (see the X direction in FIG. 6). The direction in which the first metal part 121 points to the second metal part 122 can refer to the positive direction of the Z direction in FIG. 7; the direction in which the second metal part 122 points to the first metal part 121 can refer to the negative direction of the Z direction in FIG. 7.

[0257] In some examples, along the first direction, the metal layer 12 is divided into two parts, one part covered with the active material layer 20 is the first metal part 121, and the part not covered with the active material layer 20 is the second metal part 122. The first metal part 121 is of an equal-width structure, and the second metal part 122 can be of an equal-width structure with the first metal part 121, or a protruding structure arranged on one side of the first metal part 121, or other structures. The interface between the first metal part 121 and the second metal part 122 can refer to the end surface of the active material layer 20 close to the second metal part 122 (see the dashed line Q in FIG. 7). The end of the active material layer 20 close to the second metal part 122 can be subjected to a thinning process to reduce the rolling pressure on the end of the active material layer 20 close to the second metal part 122 during the rolling of the active material layer 20, thereby reducing the damage to the metal layer 12. The end surface of the active material layer 20 close to the second metal part 122 is a plane, which can also be approximately a straight line.

[0258] In some examples, the conductive member 30 and the electrode lead-out portion 2011 can be electrically connected by welding or conductive glue or the like.

[0259] In some examples, the conductive member 30 is welded to the surface of the second metal portion 122 facing away from the insulating base 11. Compared with the end surface of the second metal portion 122 facing away from the first metal portion 121, the surface of the second metal portion 122 facing away from the insulating base 11 has a larger area, which is conducive to increasing the welding area between the conductive member 30 and the second metal portion 122, improving the flow area between the conductive member 30 and the second metal portion 122, and improving the flow capacity of the first tab 1 and the fast-charging performance of the battery monomer 100.

[0260] The welding mark formed by welding the conductive member 30 to the surface of the second metal portion 122 facing away from the insulating base 11 is a first welding mark 51.

[0261] The electrode assembly 101 includes a first insulating piece 41 covering the surface of the conductive member 30 facing away from the second metal portion 122 and covering the first welding mark 51. The first insulating piece 41 can cover part of the first welding mark 51 or the entire first welding mark 51. The first insulating piece 41 can block burrs of the first welding mark 51, thereby reducing the risk of the burrs of the first welding mark 51 piercing the separator 3 and contacting the second tab 2, reducing the risk of short circuit of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0262] The first insulating piece 41 is made of an insulating material, for example, PP (polypropylene), PET (polyethylene terephthalate), or the like. The first insulating piece 41 can be, but is not limited to, an insulating coating, insulating glue (for example, hot melt glue), or an insulating adhesive tape.

[0263] In some examples, the first insulating piece 41 can be fixed to the first welding mark 51 by pasting or static adsorption or the like.

[0264] By adopting the technical solutions of this embodiment, the first insulating piece 41 covers at least part of the first welding mark 51, the first insulating piece 41 can block burrs of the first welding mark 51, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100. The current collector 10 adopts a composite structure of the insulating base 11 and the metal layer 12. Compared with a pure metal current collector 10, the metal layer 12 has a smaller thickness, and the current collector 10 generates smaller burrs during the manufacturing process, thereby reducing the risk of internal short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0265] In some embodiments, referring to FIGS. 7, 8 and 9, the conductive member 30 includes a first connecting portion 31 and at least one second connecting portion 32, the first connecting portion 31 is welded to the surface of the second metal portion 122 facing away from the insulating substrate 11 and forms the first welding mark 51, and the second connecting portion 32 is connected to the side of the first connecting portion 31 facing away from the active material layer 20, and the second connecting portion 32 is electrically connected to the electrode lead-out portion 2011.

[0266] The first connecting portion 31 can be a portion for welding the conductive member 30 to the second metal portion 122, and the second connecting portion 32 can be a portion for connecting the conductive member 30 to the electrode lead-out portion 2011.

[0267] In some examples, the first connecting portion 31 can be overlaid on the second metal portion 122 and welded to the second metal portion 122, the second connecting portion 32 can extend from the side of the first connecting portion 31 facing away from the active material layer 20 in the first direction and away from the active material layer 20, the second connecting portion 32 protrudes out of the insulating substrate 11, i.e. in the thickness direction of the current collector 10, the projection of the first connecting portion 31 is located within the projection of the second metal portion 122, the projection of the second connecting portion 32 is located outside the projection range of the second metal portion 122, the first connecting portion 31 and the second connecting portion 32 are divided based on the end surface of the second metal portion 122 facing away from the first metal portion 121; the connection positions of the second metal portion 122 and the electrode lead-out portion 2011 on the conductive member 30 are different, which facilitates connection and can reduce the mutual influence between the two connections, and is conducive to connection reliability.

[0268] In some examples, the first connecting portion 31 is overlaid on the surface of the second metal portion 122 facing away from the insulating substrate 11 and is welded to the surface of the second metal portion 122 facing away from the insulating substrate 11, and the welding mark formed by welding is the first welding mark 51.

[0269] In some examples, the second connecting portion 32 and the electrode lead-out portion 2011 can be electrically connected by direct welding, or can be welded through a conductive piece (such as a jumper, etc.), and the welding method is convenient for connection and processing. Of course, other methods can also be used to achieve electrical connection.

[0270] In some examples, when the pole piece is wound to form the electrode assembly 101, the insulating base 11 insulates the adjacent two layers of the metal layer 12, which makes it difficult to directly connect the adjacent two layers of the metal layer 12 to transmit current outward through the insulating base 11, so that the current can be transmitted outward only by the outermost layer of the metal layer 12, resulting in poor conductivity, low fast-charging performance, and easy local overheating, which affects the use reliability of the battery monomer 100. The battery monomer 100 of the embodiment of the application uses the first connecting part 31 of the conductive member 30 to be welded with the second metal part 122, and the second connecting part 32 of the conductive member 30 protrudes out of the insulating base 11, so that the second connecting part 32 can be used to electrically conduct the adjacent two layers of the metal layer 12, thereby breaking the insulation limitation of the insulating base 11, effectively improving the conductivity of the first pole piece 1, improving the fast-charging performance of the battery monomer 100, reducing the heat production of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0271] In some examples, when the pole piece is stacked to form the electrode assembly 101, the insulating base 11 insulates the adjacent two metal layers 12, which makes it difficult to directly connect the adjacent two metal layers 12 to transmit current outward through the insulating base 11, so that the current can be transmitted outward only by the metal layer 12 located at the outermost side, resulting in poor conductivity, low fast-charging performance, and easy local overheating, which affects the use reliability of the battery monomer 100. The battery monomer 100 of the embodiment of the application uses the first connecting part 31 of the conductive member 30 to be welded with the second metal part 122, and the second connecting part 32 of the conductive member 30 protrudes out of the insulating base 11, so that the second connecting part 32 can be used to electrically conduct the adjacent two metal layers 12, thereby breaking the insulation limitation of the insulating base 11, effectively improving the conductivity of the first pole piece 1, improving the fast-charging performance of the battery monomer 100, reducing the heat production of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0272] By adopting the technical solution of the embodiment, the second connecting part 32 is provided, which can facilitate the connection of the second connecting part 32 with the electrode lead-out part 2011, and the manufacturing of the battery monomer 100 is more convenient.

[0273] In some embodiments, referring to FIGS. 8-11, the second metal part 122 includes at least one protruding part 1222; along the second direction, the sum of the sizes of all the protruding parts 1222 is less than the size of the first metal part 121, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10; the first connecting part 31 includes at least one first connecting sub-part 311, the first connecting sub-part 311 is connected with the second connecting part 32, the first connecting sub-part 311 covers the surface of the protruding part 1222 away from the insulating base 11, and the first connecting sub-part 311 corresponds to the protruding part 1222 one by one.

[0274] The protruding portion 1222 can refer to a protruding structure formed by the edge of the metal layer 12, so that the edge of the metal layer 12 is in a stepped structure, and the number of the protruding portion 1222 can be one or more; when the number of the protruding portion 1222 is one, the size of the protruding portion 1222 in the second direction is smaller than the size of the first metal portion 121; when the number of the protruding portion 1222 is more than one, the plurality of protruding portions 1222 are arranged at intervals in the second direction, and the sum of the sizes of all the protruding portions 1222 in the second direction is smaller than the size of the first metal portion 121.

[0275] In some examples, the size of the protruding portion 1222 in the second direction is l1, the size of the first metal portion 121 is L1, and the number of the protruding portion 1222 is N, wherein, when the number of the protruding portion 1222 is one, l1 < L1; when the number of the protruding portion 1222 is more than one, the plurality of protruding portions 1222 have the same structure, and N*l1 < L1.

[0276] In some examples, the second metal portion 122 only includes the protruding portion 1222, which can refer to a protruding structure directly extending from the edge of the first metal portion 121.

[0277] In some examples, the second metal portion 122 includes the protruding portion 1222 and another portion (for example, the transition portion 1221, etc.) connected between the protruding portion 1222 and the first metal portion 121, and the protruding portion 1222 extends outward from the side of the other portion away from the first metal portion 121.

[0278] The first connecting sub-portion 311 can refer to the portion of the first connecting portion 31 covering the surface of the protruding portion 1222 away from the insulating base 11; in some examples, the projection of the first connecting sub-portion 311 in the thickness direction of the current collector 10 is located within the projection of the protruding portion 1222.

[0279] In some examples, the number of the protruding portion 1222 is the same as the number of the first connecting sub-portion 311, and the first connecting sub-portion 311 covers the protruding portion 1222 one by one.

[0280] By adopting the technical solution of this embodiment, the size of all the protruding portions 1222 in the second direction is smaller than the size of the first metal portion 121, and the size of the protruding portion 1222 in the second direction is small, which can save space and be conducive to improving the volume energy density of the battery monomer 100.

[0281] In some embodiments, referring to FIGS. 7-11, the first insulating member 41 includes at least one first insulating portion 4121 covering the surface of the first connecting sub-portion 311 away from the protruding portion 1222, and the first connecting sub-portion 311 corresponds to the first connecting sub-portion 311 one by one.

[0282] The first insulation part 4121 can refer to a part of the first insulation member 41 covering the first connecting sub-part 311. The first insulation part 4121 can cover a part of the first connecting sub-part 311 or the entire first connecting sub-part 311.

[0283] In some examples, the number of the first insulation parts 4121 is the same as the number of the first connecting sub-parts 311, and the first insulation parts 4121 are arranged one-to-one corresponding to the first connecting sub-parts 311.

[0284] By adopting the technical solution of this embodiment, the first insulation part 4121 covers the first connecting sub-part 311, which can realize insulation of the first connecting sub-part 311, and is conducive to reducing the risk of short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0285] In some embodiments, referring to FIGS. 7-11, the first welding mark 51 includes at least one first welding mark part 511, the first connecting sub-part 311 is welded to the surface of the protruding part 1222 away from the insulation base body 11 and forms the first welding mark part 511, and the first insulation part 4121 covers at least part of the first welding mark part 511.

[0286] The first welding mark part 511 can refer to a welding mark formed by welding of the first connecting sub-part 311 and the protruding part 1222.

[0287] The first insulation part 4121 can cover a part of the first welding mark part 511, or the first insulation part 4121 covers the entire first welding mark part 511.

[0288] In the process of manufacturing the first tab 1, the conductive member 30 can be welded to the edge of the equal-length current collector 10 by ultrasonic welding (for example, double-roller continuous ultrasonic welding) or other welding methods, and an equal-width welding mark is formed. Then, the conductive member 30 is cut by laser die cutting or other cutting methods to form a tab, which is convenient for connecting with the electrode lead-out part 2011. In the cutting process, first, cutting is performed along the second direction at a position between the equal-width welding mark and the active material layer 20, and then cutting is performed toward the equal-width welding mark until the equal-width welding mark is left, and then cutting is continuously performed away from the active material layer 20 for a distance, and then cutting is continuously performed along the second direction for a distance, and then cutting is performed toward the equal-width welding mark until the equal-width welding mark is left, and then cutting is performed along the second direction. In this way, a first welding mark part 511 can be obtained, and a plurality of first welding mark parts 511 can be obtained after multiple cutting.

[0289] By adopting the technical scheme of the embodiment, the first connecting sub-portion 311 is welded to the protruding portion 1222, the connection between the first connecting sub-portion 311 and the protruding portion 1222 is achieved, the structure is simple, and the manufacturing is convenient; the first insulating portion 4121 can block burrs on the first welding mark portion 511, reduce the short circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0290] In some embodiments, referring to FIGS. 7-11, the protruding portion 1222 includes a first protruding sub-portion 12221 and a second protruding sub-portion 12222, the first protruding sub-portion 12221 is connected between the second protruding sub-portion 12222 and the first metal portion 121; along the second direction, the size of the first protruding sub-portion 12221 is greater than the size of the second protruding sub-portion 12222; the first welding mark portion 511 includes a first welding mark sub-portion 5111, the first connecting portion 31 is welded to the first protruding sub-portion 12221 and forms the first welding mark sub-portion 5111, and the first insulating portion 4121 covers at least part of the first welding mark sub-portion 5111.

[0291] The protruding portion 1222 has a stepped structure, along the first direction, the protruding portion 1222 is divided into two parts, the part close to the first metal portion 121 is the first protruding sub-portion 12221, and the part away from the first metal portion 121 is the second protruding sub-portion 12222; along the second direction, the size of the first protruding sub-portion 12221 is l2, the size of the second protruding sub-portion 12222 is l3, l2>l3, which is equivalent to increasing the size of the first protruding sub-portion 12221 along the second direction, improving the flow area between the protruding portion 1222 and the first metal portion 121, improving the flow capacity of the first pole piece 1, reducing the heat generation of the battery monomer 100, and improving the fast charging performance of the battery monomer 100.

[0292] The first connecting portion 31 is welded to the surface of the first protruding sub-portion 12221 away from the insulating base body 11, and the welding mark generated by the welding is the first welding mark sub-portion 5111.

[0293] The first insulating portion 4121 can cover part of the first welding mark sub-portion 5111, or cover the entire first welding mark sub-portion 5111.

[0294] By adopting the technical scheme of this embodiment, the size of the first protruding sub-part 12221 is large in the second direction, which is beneficial to increase the welding area of the first protruding sub-part 12221 and the first connecting part 31, increase the flow area between the protruding part 1222 and the first connecting part 31, and improve the flow capacity between the protruding part 1222 and the first connecting part 31, thereby reducing the heat generation of the battery monomer 100 and improving the fast-charging performance and use reliability of the battery monomer 100; the size of the second protruding sub-part 12222 is small relative to the size of the first protruding sub-part 12221 in the second direction, which is beneficial to reduce the occupied space of the protruding part 1222 and improve the energy density of the battery monomer 100; the first insulating part 4121 covers at least part of the first welding sub-part 5111, and the first insulating part 4121 can block burrs of the first welding sub-part 5111, thereby improving the use reliability of the battery monomer 100.

[0295] In some embodiments, referring to FIGS. 7-11, the first welding part 511 includes a second welding sub-part 5112, the first connecting part 31 is welded to the second protruding sub-part 12222 and forms the second welding sub-part 5112, and the first insulating part 4121 covers at least part of the second welding sub-part 5112.

[0296] The surface of the second protruding sub-part 12222 away from the insulating base 11 is welded to the first connecting part 31, and the welding produces a second welding sub-part 5112. The first insulating part 4121 can cover part of the second welding sub-part 5112 or cover the entire second welding sub-part 5112.

[0297] By adopting the technical scheme of this embodiment, the second protruding sub-part 12222 is welded to the first connecting part 31, which can realize the welding connection between the protruding part 1222 and the first connecting part 31; the first insulating part 4121 covers at least part of the second welding sub-part 5112, and the first insulating part 4121 can block burrs of the second welding sub-part 5112, thereby improving the use reliability of the battery monomer 100.

[0298] In some embodiments, referring to FIGS. 7-11, the first welding part 511 includes a first welding sub-part 5111, the first connecting part 31 is welded to the first protruding sub-part 12221 and forms the first welding sub-part 5111, and the first insulating part 4121 covers at least part of the first welding sub-part 5111; the first welding part 511 includes a second welding sub-part 5112, the first connecting part 31 is welded to the second protruding sub-part 12222 and forms the second welding sub-part 5112, and the first insulating part 4121 covers at least part of the second welding sub-part 5112.

[0299] By adopting the technical scheme of the embodiment, the first protruding sub-part 12221 and the second protruding sub-part 12222 are both welded with the first connecting part 31, the welding area between the first connecting part 31 and the protruding part 1222 is increased, the flow capacity between the first connecting part 31 and the protruding part 1222 is increased, and the fast charging performance of the battery monomer 100 is improved; in addition, the first insulating part 4121 covers the first welding mark sub-part 5111 and the second welding mark sub-part 5112, the first insulating part 4121 can block the burrs of the first welding mark sub-part 5111 and the second welding mark sub-part 5112, the short circuit risk of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0300] In some embodiments, referring to FIGS. 7-11, the first insulating part 4121 protrudes from the edge of the first welding part 511 farthest from the active material layer 20 in the direction of the first metal part 121 pointing to the second metal part 122.

[0301] In the thickness direction of the current collector 10, the projection of the edge of the first welding part 511 farthest from the active material layer 20 is located within the projection of the first insulating part 4121.

[0302] In some examples, the first insulating part 4121 protrudes from the edge of the first welding part 511 farthest from the active material layer 20 in the direction of the first metal part 121 pointing to the second metal part 122.

[0303] In some examples, the first welding part 511 only includes the first welding sub-part 5111, and the first insulating part 4121 protrudes from the edge of the first welding sub-part 5111 farthest from the active material layer 20 in the direction of the first metal part 121 pointing to the second metal part 122.

[0304] In some examples, the first welding part 511 only includes the second welding sub-part 5112, and the first insulating part 4121 protrudes from the edge of the second welding sub-part 5112 farthest from the active material layer 20 in the direction of the first metal part 121 pointing to the second metal part 122.

[0305] In some examples, the first welding part 511 includes the first welding sub-part 5111 and the second welding sub-part 5112, and the first welding sub-part 5111 and the second welding sub-part 5112 can be directly connected, i.e., the first welding sub-part 5111 and the second welding sub-part 5112 can be a whole welding mark; of course, the first welding sub-part 5111 and the second welding sub-part 5112 can also be arranged at intervals; the first insulating part 4121 protrudes from the edge of the second welding sub-part 5112 farthest from the active material layer 20 in the direction of the first metal part 121 pointing to the second metal part 122.

[0306] In some examples, the first welding portion 511 includes a first welding sub-portion 5111 and a second welding sub-portion 5112, and the first insulating portion 4121 can protrude from an edge of the first welding sub-portion 5111 away from the active material layer 20 in a direction in which the first metal portion 121 points to the second metal portion 122.

[0307] By adopting the technical solutions of this embodiment, the first insulating portion 4121 covers the edge of the first welding 51 away from the active material layer 20, the first insulating portion 4121 can block burrs at the edge of the first welding 51 away from the active material layer 20, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0308] In some embodiments, referring to FIGS. 7-11, the first insulating portion 4121 protrudes from an edge of the first welding portion 511 close to the active material layer 20 in a direction in which the second metal portion 122 points to the first metal portion 121.

[0309] In the thickness direction of the current collector 10, the projection of the edge of the first welding portion 511 away from the active material layer 20 is located within the projection of the first insulating portion 4121.

[0310] In some examples, the first insulating portion 4121 protrudes from an edge of the first welding portion 511 closest to the active material layer 20 in a direction in which the second metal portion 122 points to the first metal portion 121.

[0311] In some examples, the first welding portion 511 only includes the first welding sub-portion 5111, and the first insulating portion 4121 protrudes from an edge of the first welding sub-portion 5111 close to the active material layer 20 in a direction in which the second metal portion 122 points to the first metal portion 121.

[0312] In some examples, the first welding portion 511 only includes the second welding sub-portion 5112, and the first insulating portion 4121 protrudes from an edge of the second welding sub-portion 5112 close to the active material layer 20 in a direction in which the second metal portion 122 points to the first metal portion 121.

[0313] In some examples, the first welding portion 511 includes the first welding sub-portion 5111 and the second welding sub-portion 5112, the first welding sub-portion 5111 and the second welding sub-portion 5112 can be directly connected or spaced apart, and the first insulating portion 4121 protrudes from an edge of the first welding sub-portion 5111 close to the active material layer 20 in a direction in which the second metal portion 122 points to the first metal portion 121.

[0314] In some examples, the first welding portion 511 includes a first welding sub-portion 5111 and a second welding sub-portion 5112, and the first insulating portion 4121 protrudes from an edge of the second welding sub-portion 5112 close to the active material layer 20 in a direction pointing from the second metal portion 122 to the first metal portion 121.

[0315] By adopting the technical solutions of this embodiment, the first insulating portion 4121 covers the edge of the first welding portion 511 close to the active material layer 20, the first insulating portion 4121 can block burrs at the edge of the first welding portion 511 close to the active material layer 20, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0316] In some examples, referring to FIGS. 7-11, the first insulating portion 4121 protrudes from an edge of the first welding portion 511 away from the active material layer 20 in a direction pointing from the first metal portion 121 to the second metal portion 122; and the first insulating portion 4121 protrudes from an edge of the first welding portion 511 close to the active material layer 20 in a direction pointing from the second metal portion 122 to the first metal portion 121.

[0317] In the thickness direction of the current collector 10, a projection of the edge of the first welding portion 511 close to the active material layer 20 is located within a projection of the first insulating portion 4121, and a projection of the edge of the first welding portion 511 away from the active material layer 20 is located within the projection of the first insulating portion 4121.

[0318] In some examples, in the thickness direction of the current collector 10, a projection of the first welding portion 511 is located within a projection of the first insulating portion 4121, so as to achieve full coverage of the first welding portion 511.

[0319] By adopting the technical solutions of this embodiment, in the first direction, the opposite two sides of the first insulating portion 4121 can protrude from the opposite two edges of the first welding portion 511, the coverage area of the first insulating portion 4121 is large, the burr blocking effect on the first welding portion 511 is good, the short circuit risk of the battery monomer 100 is small, and the use reliability of the battery monomer 100 is good.

[0320] In some examples, referring to FIGS. 7-11, in the second direction, the opposite two side surfaces of the protruding portion 1222 are flush with the opposite two side surfaces of the corresponding first connecting sub-portion 311 respectively, and the opposite two edges of the first welding portion 511 are flush with the opposite two side surfaces of the corresponding first connecting sub-portion 311 respectively.

[0321] In the second direction, the protruding portion 1222 coincides with the corresponding connecting sub-portion, the size of the protruding portion 1222 is the same as the size of the corresponding first connecting sub-portion 311, and the size of the first connecting sub-portion 311 is the same as the size of the corresponding first welding mark portion 511. In the second direction, the first welding mark portion 511 extends from one side of the corresponding first connecting sub-portion 311 to the other side of the first connecting sub-portion 311.

[0322] In some examples, the protruding portion 1222 includes a first protruding sub-portion 12221 and a second protruding sub-portion 12222. In the second direction, the opposite two side faces of the portion of the first connecting sub-portion 311 covering the first protruding sub-portion 12221 are flush with the opposite two side faces of the first protruding sub-portion 12221, respectively, the first welding sub-mark extends from one side of the first protruding sub-portion 12221 to the other side of the first protruding sub-portion 12221, in the second direction, the opposite two side faces of the portion of the first connecting sub-portion 311 covering the second protruding sub-portion 12222 are flush with the opposite two side faces of the second protruding sub-portion 12222, respectively, and the second welding sub-mark extends from one side of the second protruding sub-portion 12222 to the other side of the second protruding sub-portion 12222.

[0323] In the process of manufacturing some first pole pieces 1, the protruding portion 1222, the first connecting portion 31, and the second connecting portion 32 are obtained by cutting. In the second direction, the opposite two side faces of the protruding portion 1222, the opposite two side faces of the corresponding first connecting sub-portion 311, and the opposite two edges of the first welding mark portion 511 are cut so that, in the second direction, the opposite two side faces of the protruding portion 1222 are flush with the opposite two side faces of the corresponding first connecting sub-portion 311, respectively, and the opposite two edges of the first welding mark portion 511 are flush with the opposite two side faces of the corresponding first connecting sub-portion 311, respectively.

[0324] By adopting the technical scheme of this embodiment, in the second direction, the opposite two side faces of the protruding portion 1222 are flush with the opposite two side faces of the corresponding first connecting sub-portion 311, respectively, the structure is regular, the manufacturing is convenient, in addition, redundancy can be reduced, space can be saved, and the energy density of the battery monomer 100 can be improved; in the second direction, the first welding mark portion 511 extends from one side of the first connecting sub-portion 311 to the other side of the second connecting sub-portion 312, in the second direction, the size of the first welding mark portion 511 is large, which is conducive to improving the welding area of the protruding portion 1222 and the first connecting portion 31, improving the flow area between the protruding portion 1222 and the first connecting portion 31, improving the flow capacity, reducing the heat generation of the battery monomer 100, and improving the fast-charging performance and use reliability of the battery monomer 100.

[0325] In some embodiments, referring to FIG. 7, in the second direction, at least one of the opposite two side portions of the first insulating portion 4121 protrudes from the side face on the same side of the corresponding first connecting sub-portion 311.

[0326] In the second direction, one side of the first insulating portion 4121 protrudes from the side surface of the first connecting sub-portion 311 on the same side as the side surface.

[0327] In some battery monomers 100, after the first connecting sub-portion 311 is cut, a sharp end protrusion can be generated at the side surface of the first connecting sub-portion 311 in the second direction, and the distance between the first connecting sub-portion 311 and the active material layer 20 is close, the distance between the first connecting sub-portion 311 and the second pole piece 2 is close, and the sharp end protrusion can be overlapped with the second pole piece 2, thereby causing a short circuit of the battery monomer 100; in particular, in the second direction, opposite edges of the first welding mark portion 511 are cut, and a large sharp end protrusion can be generated at the edge of the first welding mark portion 511; and in the second direction, the side of the first insulating portion 4121 protrudes from the corresponding edge of the first welding mark portion 511, which can block the sharp end protrusion, and can better improve the use reliability of the battery monomer 100.

[0328] By adopting the technical scheme of the embodiment, the first insulating portion 4121 can block the sharp end protrusion at the side surface of the first connecting sub-portion 311 distributed in the second direction, reduce the short circuit risk of the battery monomer 100, and be conducive to improving the use reliability of the battery monomer 100.

[0329] In some embodiments, in the direction of the first metal portion 121 pointing to the second metal portion 122, the first insulating portion 4121 protrudes from the side of the corresponding first connecting sub-portion 311 away from the active material layer 20.

[0330] In the thickness direction of the current collector 10, the projection of the side surface of the first connecting sub-portion 311 away from the active material layer 20 falls within the projection of the first insulating portion 4121.

[0331] In some examples, the side surface of the first connecting sub-portion 311 away from the active material layer 20 can refer to the interface between the first connecting sub-portion 311 and the second connecting portion 32, and the interface between the second connecting sub-portion 312 and the second connecting portion 32 can refer to the end surface of the protruding portion 1222 facing away from the first metal portion 121 (which can refer to the dashed line M in FIG. 7). In the direction of the first metal portion 121 pointing to the second metal portion 122, the first insulating portion 4121 protrudes from the interface between the first connecting sub-portion 311 and the second connecting portion 32, and the first insulating portion 4121 can extend to the second connecting portion 32.

[0332] In some examples, a portion of the first insulating portion 4121 can cover a partial area of the second connecting portion 32 near the first connecting sub-portion 311 or cover the entire first connecting sub-portion 311, and another portion of the first insulating portion 4121 can cover a partial area of the second connecting portion 32 near the first connecting sub-portion 311, and a partial area of the second connecting portion 32 away from the first connecting sub-portion 311 is not covered by the first insulating portion 4121, so as to facilitate electrical connection between the partial area of the second connecting portion 32 away from the first connecting sub-portion 311 and the electrode lead-out portion 2011.

[0333] In some examples, when the first welding portion 511 is covered by the first insulating portion 4121, the first insulating portion 4121 can cover an edge of the first welding portion 51 away from the active material layer 20, and the first insulating portion 4121 can block burrs at the edge of the first welding portion 51 near the active material layer 20, so as to reduce the risk of short circuit of the battery monomer 100.

[0334] By adopting the technical solutions of the embodiment, the first insulating portion 4121 can extend from the first welding portion 51 to the second connecting portion 32, so that the first insulating portion 4121 can cover an edge of the first welding portion 51 away from the active material layer 20, and the first insulating portion 4121 can block burrs at the edge of the first welding portion 51 away from the active material layer 20, so as to reduce the risk of short circuit of the battery monomer 100; in addition, the first insulating portion 4121 can cover at least part of the second connecting portion 32, so as to at least achieve insulation of at least part of the second connecting portion 32, which is conducive to reducing the risk of short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0335] In some embodiments, in a direction from the second metal portion 122 to the first metal portion 121, the first insulating portion 4121 protrudes from a side of the corresponding first connecting sub-portion 311 near the active material layer 20.

[0336] In a thickness direction of the current collector 10, a projection of the side of the first connecting sub-portion 311 near the active material layer 20 falls within a projection of the corresponding first insulating portion 4121.

[0337] In some examples, in a direction from the second metal portion 122 to the first metal portion 121, the first insulating portion 4121 protrudes from a side of the first connecting sub-portion 311 near the active material layer 20.

[0338] In some examples, when the first welding portion 511 is covered by the first insulating portion 4121, the first insulating portion 4121 can cover an edge of the first welding portion 51 near the active material layer 20, and the first insulating portion 4121 can block burrs at the edge of the first welding portion 51 near the active material layer 20, so as to reduce the risk of short circuit of the battery monomer 100.

[0339] By adopting the technical solutions of this embodiment, the first insulating portion 4121 can cover the side of the first connecting sub-portion 311 close to the active material layer 20, can block burrs at the side of the first connecting sub-portion 311 close to the active material layer 20, and can reduce the risk of short circuit of the battery monomer 100.

[0340] In some embodiments, referring to FIGS. 7-11, in a direction in which the second metal portion 122 points to the first metal portion 121, the first insulating portion 4121 protrudes from a side of the corresponding first connecting sub-portion 311 close to the active material layer 20, and in the direction in which the second metal portion 122 points to the first metal portion 121, the first insulating portion 4121 protrudes from a side of the corresponding first connecting sub-portion 311 close to the active material layer 20.

[0341] In the first direction, opposite sides of the first insulating portion 4121 protrude from opposite sides of the first connecting sub-portion 311, respectively.

[0342] In some examples, the first connecting sub-portion 311 is welded to the protruding portion 1222 to form a first welding mark portion 511, and in the first direction, the first insulating portion 4121 can cover the entire first welding mark portion 511, the first insulating portion 4121 can block burrs at edges of the first welding mark 51 close to the active material layer 20, and the risk of short circuit of the battery monomer 100 can be reduced.

[0343] By adopting the technical solutions of this embodiment, in the first direction, the first insulating portion 4121 can completely cover the first connecting sub-portion 311, the insulation effect of the first connecting sub-portion 311 is improved, the risk of short circuit of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0344] In some embodiments, referring to FIGS. 7-11, the number of the protruding portions 1222 is multiple, the first connecting portion 31 includes multiple first connecting sub-portions 311, the multiple protruding portions 1222 are arranged at intervals in a second direction, and the multiple first connecting sub-portions 311 are arranged at intervals in the second direction; the number of the second connecting portions 32 is multiple, the multiple second connecting portions 32 are arranged at intervals in the second direction, and the first connecting sub-portion 311 and the second connecting portion 32 correspond to each other in connection.

[0345] In the case where the number of the protruding portions 1222 is multiple, the multiple protruding portions 1222 are arranged at intervals in the second direction, each protruding portion 1222 corresponds to cover one first connecting sub-portion 311, each first connecting sub-portion 311 corresponds to connect one second connecting portion 32, the multiple second connecting portions 32 are arranged at intervals in the second direction, and each first connecting sub-portion 311 corresponds to cover one first insulating portion 4121. After the pole piece is wound, the multiple protruding portions 1222 can be stacked together, so that the multiple second connecting portions 32 are also stacked together, to facilitate electrical connection with the electrode lead-out portion 2011.

[0346] By adopting the technical solutions of this embodiment, the plurality of protrusions 1222 are arranged at intervals along the second direction, which facilitates the division of the first metal part 121 into a plurality of regions along the second direction, and one region can correspond to one protrusion 1222. The electrons in each region can be transmitted to the electrode lead-out part 2011 through the corresponding protrusion 1222, and the regional transmission of the electrons of the first metal part 121 can be achieved. The transmission path of the electrons in each region is short to the corresponding protrusion 1222, which facilitates the reduction of the transmission distance of the electrons and the overall resistance of the first electrode sheet 1, and improves the fast-charging performance and use reliability of the battery monomer 100.

[0347] In some embodiments, the two adjacent first insulating parts 4121 are arranged to be disconnected.

[0348] By adopting the technical solutions of this embodiment, the two adjacent first insulating parts 4121 are arranged at intervals, which can save space and facilitate the improvement of the energy density of the battery monomer 100.

[0349] In some embodiments, referring to FIGS. 6 and 12, the two adjacent first insulating parts 4121 are connected.

[0350] In some examples, referring to FIG. 6, the first insulating part 41 extends along the second direction and has an equal-width structure. The first insulating part 41 is divided into a plurality of first insulating parts 4121 along the second direction, and the plurality of first insulating parts 4121 are connected in sequence along the second direction and form an overall structure.

[0351] In some examples, referring to FIG. 12, the first insulating part 41 extends along the second direction and has an equal-width structure. The first insulating part 41 is divided into two parts along the first direction, wherein the part close to the active material layer 20 is a second insulating part 4122, and the part away from the active material layer 20 can be divided into a plurality of first insulating parts 4121 along the second direction. The plurality of first insulating parts 4121 are connected in sequence along the second direction and form an overall structure.

[0352] By adopting the technical solutions of this embodiment, the two adjacent first insulating parts 4121 can be directly connected to form an overall structure, which facilitates the installation of the first insulating part 4121. At the same time, the first insulating part 4121 can also cover the opposite two side surfaces of the first connecting sub-part 311 along the second direction, block the sharp protrusions at the opposite two side surfaces of the first connecting sub-part 311 along the second direction, improve the short-circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0353] In some embodiments, referring to FIGS. 12-16, the second metal part 122 includes a transition part 1221 and at least one protruding part 1222, the transition part 1221 is connected between the protruding part 1222 and the first metal part 121, and the size of the transition part 1221 is greater than the sum of the sizes of all the protruding parts 1222 along the second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0354] Along the first direction, the second metal part 122 is divided into two parts, the part close to the first metal part 121 is the transition part 1221, the part away from the first metal part 121 is the first metal part 121, and the protruding part 1222 protrudes away from the edge of the transition part 1221 away from the first metal part 121 and faces away from the first metal part 121; the first metal part 121 is covered with the active material layer 20, and the transition part 1221 and the protruding part 1222 are not covered with the active material layer 20. Along the second direction, the size of the transition part 1221 is greater than the sum of the sizes of all the protruding parts 1222, so that the size of the transition part 1221 can be close to the size of the first metal part 121.

[0355] In some examples, the protruding part 1222 extends outward along the first direction from the side of the transition part 1221 facing away from the first metal part 121; the number of the protruding part 1222 is one, the protruding part 1222 forms a stepped structure with the transition part 1221, along the second direction, the size of the transition part 1221 is L2, L2>l1; the number of the protruding part 1222 is multiple, the multiple protruding parts 1222 protrude from the edge of the same side of the transition part 1221, the multiple protruding parts 1222 are arranged at intervals along the second direction, the multiple protruding parts 1222 have the same structure, and L2>N*l1.

[0356] By adopting the technical scheme of this embodiment, the size of the transition part 1221 along the second direction is large, so that the transition part 1221 can have a larger area to connect with the first connecting part 31, thereby the electrons of the first metal part 121 and the active material layer 20 can flow directly to the first connecting part 31 through the transition part 1221, the overcurrent pressure between the protruding part 1222 and the transition part 1221 can be reduced, the heat at the connection between the protruding part 1222 and the transition part 1221 is reduced, and the fast-charging performance of the battery monomer 100 is improved.

[0357] In some embodiments, referring to FIGS. 12-16, along the second direction, the size of the first metal part 121 is L1, the size of the transition part 1221 is L2, and 0.8≤L2 / L1≤1.

[0358] 0.8≤L2 / L1≤1, along the second direction, the size of the transition portion 1221 is less than or equal to the size of the first metal portion 121, and the size of the transition portion 1221 is greater than or equal to 0.8 times the size of the first metal portion 121, so that the size of the transition portion 1221 is not much different from or equal to the size of the first metal portion 121, wherein the larger the size of the transition portion 1221, the larger the connection area of the transition portion 1221 and the first connecting portion 31 can be set, and the better the flow capacity between the transition portion 1221 and the first connecting portion 31.

[0359] The value of L2 / L1 can be, but is not limited to, 0.8, 1, or any value between 0.8 and 1. For example, the value of L2 / L1 can be, but is not limited to, 0.8, 0.85, 0.9, 0.95, or 1.

[0360] In some examples, 0.8≤L2 / L1<1, along the second direction, the transition portion 1221 can be located at the middle position of the first metal portion 121, and the two ends of the transition portion 1221 are flush with the first metal portion 121.

[0361] In some examples, 0.8≤L2 / L1<1, along the second direction, the transition portion 1221 can be located at the middle position of the first metal portion 121, and the two ends of the transition portion 1221 are flush with the first metal portion 121.

[0362] In some examples, L2=L1, along the second direction, the size of the transition portion 1221 is equal to the size of the first metal portion 121, along the second direction, the two ends of the transition portion 1221 are flush with the first metal portion 121, and the transition portion 1221 and the first metal portion 121 are equal-length structures.

[0363] By adopting the technical solutions of this embodiment, the design of 0.8≤L2 / L1≤1 makes the size of the transition portion 1221 along the second direction larger, which is beneficial to increasing the connection area between the first connecting portion 31 and the transition portion 1221, improving the flow capacity at the connection between the first connecting portion 31 and the transition portion 1221, improving the flow capacity of the first pole piece 1, reducing the heat generation of the battery monomer 100, and improving the fast-charging performance of the battery monomer 100.

[0364] In some embodiments, please refer to FIGS. 12-16, the first welding mark 51 includes a second welding mark portion 512, and the first connecting portion 31 includes a second connecting sub-portion 312 connected with the second connecting portion 32, and the second connecting sub-portion 312 is welded to the transition portion 1221 and forms the second welding mark portion 512.

[0365] The second connecting sub-portion 312 can refer to a portion where the first connecting portion 31 is connected to the transition portion 1221; the welding mark generated by welding the surface of the transition portion 1221 away from the insulating base 11 is the second welding mark portion 512.

[0366] In some examples, the first connecting portion 31 includes a first connecting sub-portion 311 and a second connecting sub-portion 312, the first connecting sub-portion 311 is connected between the second connecting sub-portion 312 and the second connecting portion 32, and the interface between the first connecting sub-portion 311 and the second connecting sub-portion 312 can refer to the end surface of the transition portion 1221 leading to the protruding portion 1222 (which can refer to the dashed line N in FIG. 18).

[0367] In some examples, the first connecting sub-portion 311 is welded to the protruding portion 1222 to form the first welding mark portion 511, and the second connecting sub-portion 312 is welded to the transition portion 1221 to form the second welding mark portion 512; the first welding mark portion 511 and the second welding mark portion 512 together form the first welding mark 51, and the first welding mark portion 511 is located between the second welding mark portion 512 and the active material layer 20, that is, the first connecting portion 31 is welded to both the transition portion 1221 and the protruding portion 1222.

[0368] In some examples, the second connecting sub-portion 312 is welded to the transition portion 1221 to form the second welding mark portion 512, and the protruding portion 1222 is not welded to the first connecting sub-portion 311; the second welding mark portion 512 is the first welding mark 51.

[0369] In the process of manufacturing some first pole piece 1, cutting is first performed on the equal-width welding mark in the second direction, then cutting is performed in the direction away from the active material layer 20 until the equal-width welding mark is left, then cutting is continued in the direction away from the active material layer 20 for a distance, then cutting is continued in the second direction for a distance, then cutting is performed in the direction toward the active material layer 20 until the equal-width welding mark is cut for a distance, and then cutting is continued in the second direction on the equal-width welding mark, so as to obtain the second welding mark portion 512 and one first welding mark portion 511; after multiple cutting, multiple first welding mark portions 511 can be obtained; wherein, based on the cutting position in the second direction on the equal-width welding mark as a reference, in the first direction, the portion of the first welding mark 51 on the side of the cutting position toward the active material layer 20 is the second welding mark portion 512, and the portion on the side of the cutting position away from the active material layer 20 is the first welding mark portion 511; the first welding mark portion 511 can be a protruding structure extending out from the side of the second welding mark portion 512 away from the active material layer 20; and after the cutting is completed, the metal layer 12 of the current collector 10 cuts out the protruding portion 1222, and the portion of the metal layer 12 between the protruding portion 1222 and the active material layer 20 forms the transition portion 1221.

[0370] By adopting the technical scheme of the embodiment, the surface of the transition portion 1221 away from the insulating base body 11 is welded with the first connecting portion 31, so that part of the current can directly flow into or out of the first connecting portion 31 through the transition portion 1221, the overcurrent pressure between the protruding portion 1222 and the transition portion 1221 is reduced, the heat generation at the connection between the protruding portion 1222 and the transition portion 1221 is reduced, and the fast-charging performance of the battery monomer 100 is improved.

[0371] In some embodiments, referring to FIGS. 12-16, the second connecting sub-portion 312 is not welded with the transition portion 1221, and the protruding portion 1222 is welded with the first connecting sub-portion 311 to form a first welding mark portion 511, and the first welding mark portion 511 is the first welding mark 51.

[0372] In some embodiments, along the second direction, the size of the transition portion 1221 is L2, and the size of the second welding mark portion 512 is L3, and 0.8≤L3 / L2≤1.

[0373] 0.8≤L3 / L2≤1, along the second direction, the size L3 of the second welding mark portion 512 can be less than or equal to the size L2 of the transition portion 1221, the size L3 of the second welding mark portion 512 is greater than or equal to 0.8 times the size L2 of the transition portion 1221, the size L3 of the second welding mark portion 512 exceeds more than half the size L2 of the transition portion 1221, the longer the size L3 of the second welding mark portion 512, the greater the welding area of the transition portion 1221 and the second connecting sub-portion 312, and the better the overcurrent capacity at the connection between the transition portion 1221 and the second connecting sub-portion 312.

[0374] In some examples, 0.8≤L3 / L2<1, along the second direction, the second welding mark portion 512 can be located at the middle position of the transition portion 1221, and the opposite two edges of the second welding mark portion 512 are not flush with the opposite two side surfaces of the transition portion 1221.

[0375] In some examples, 0.8≤L3 / L2<1, along the second direction, the second welding mark portion 512 can be located at the middle position of the transition portion 1221, and the opposite two edges of the second welding mark portion 512 are not flush with the opposite two side surfaces of the transition portion 1221.

[0376] In some examples, L3=L2, along the second direction, the size L3 of the second welding mark portion 512 is equal to the size L2 of the transition portion 1221, and the opposite two edges of the second welding mark portion 512 are flush with the opposite two side surfaces of the transition portion 1221.

[0377] The value of L3 / L2 can be, but is not limited to, 0.8, 1, or any value between 0.8 and 1. For example, the value of L3 / L2 can be, but is not limited to, 0.8, 0.85, 0.9, 0.95, or 1.

[0378] By adopting the technical solution of this embodiment, the design of 0.8≤L3 / L2≤1 makes the size of the second welding portion 512 in the second direction larger, which is conducive to increasing the connection area between the second connecting sub-portion 312 and the transition portion 1221, improving the flow capacity at the connection between the second connecting sub-portion 312 and the transition portion 1221, improving the flow capacity of the first tab 1, reducing the heat generation of the battery monomer 100, and improving the fast-charging performance of the battery monomer 100.

[0379] In some embodiments, as shown in FIGS. 12-16, the side of the transition portion 1221 facing away from the first metal portion 121, the edge of the second welding portion 512 away from the active material layer 20, and the side of the second connecting sub-portion 312 facing away from the active material layer 20 are flush.

[0380] In the thickness direction of the current collector 10, the side of the transition portion 1221 facing away from the first metal portion 121, the edge of the second welding portion 512 away from the active material layer 20, and the side of the second connecting sub-portion 312 facing away from the active material layer 20 coincide.

[0381] In the manufacturing process of the first tab 1, after the equal-width welding is cut in the second direction, the side of the transition portion 1221 facing away from the first metal portion 121, the edge of the second welding portion 512 away from the active material layer 20, and the side of the second connecting sub-portion 312 facing away from the active material layer 20 are flush.

[0382] By adopting the technical solution of this embodiment, the second welding portion 512, the second connecting sub-portion 312, and the transition portion 1221 have regular structures and are easy to manufacture. In addition, the redundancy of the second connecting sub-portion 312 and the transition portion 1221 can be reduced, space can be saved, and the energy density of the battery monomer 100 can be improved.

[0383] In some embodiments, as shown in FIGS. 12-16, the first insulating member 41 includes a second insulating portion 4122, and the second insulating portion 4122 covers at least part of the second welding portion 512.

[0384] The second insulating portion 4122 can refer to the part of the first insulating member 41 covering the second welding portion 512. The second insulating portion 4122 can cover part of the second welding portion 512, or the second insulating portion 4122 can cover the entire second welding portion 512.

[0385] By adopting the technical solutions of the embodiment, the second insulating portion 4122 can block burrs on the second welding pad portion 512, reduce the short circuit risk of the battery monomer 100, and help improve the use reliability of the battery monomer 100.

[0386] In some embodiments, along a direction in which the first metal portion 121 points to the second metal portion 122, the second insulating portion 4122 protrudes from an edge of the second welding pad portion 512 away from the active material layer 20.

[0387] Along a thickness direction of the current collector 10, a projection of the edge of the second welding pad portion 512 away from the active material layer 20 is located within a projection of the second insulating portion 4122.

[0388] By adopting the technical solutions of the embodiment, the second insulating portion 4122 can block burrs at the edge of the second welding pad portion 512 away from the active material layer 20, reduce the short circuit risk of the battery monomer 100, and help improve the use reliability of the battery monomer 100.

[0389] In some embodiments, please refer to FIGS. 12-16, along a direction in which the second metal portion 122 points to the first metal portion 121, the second insulating portion 4122 protrudes from an edge of the second welding pad portion 512 close to the active material layer 20.

[0390] Along a thickness direction of the current collector 10, a projection of the edge of the second welding pad portion 512 close to the active material layer 20 is located within a projection of the second insulating portion 4122.

[0391] By adopting the technical solutions of the embodiment, the second insulating portion 4122 can block burrs at the edge of the second welding pad portion 512 close to the active material layer 20, reduce the short circuit risk of the battery monomer 100, and help improve the use reliability of the battery monomer 100.

[0392] In some embodiments, please refer to FIGS. 12-16, along a direction in which the first metal portion 121 points to the second metal portion 122, the second insulating portion 4122 protrudes from an edge of the second welding pad portion 512 away from the active material layer 20; along a direction in which the second metal portion 122 points to the first metal portion 121, the second insulating portion 4122 protrudes from an edge of the second welding pad portion 512 close to the active material layer 20.

[0393] In some examples, along a thickness direction of the current collector 10, a projection of the second welding pad portion 512 is located within a projection of the second insulating portion 4122, and the second welding pad portion 512 can be completely covered.

[0394] By adopting the technical solutions of the embodiment, the second insulating portion 4122 can block burrs at the edges of the second welding pad portion 512 in the first direction, reduce the short circuit risk of the battery monomer 100, and help improve the use reliability of the battery monomer 100.

[0395] In some embodiments, referring to Figs. 12-16, the second insulating portion 4122 protrudes from the side of the second connecting sub-portion 312 away from the active material layer 20 in the direction from the first metal portion 121 to the second metal portion 122.

[0396] In the thickness direction of the current collector 10, the projection of the side of the second connecting sub-portion 312 away from the active material layer 20 is within the projection of the second insulating portion 4122.

[0397] In some battery monomers 100, burrs can be generated on the side of the second connecting sub-portion 312 away from the active material layer 20 during the manufacturing process, which can cause short circuit of the battery monomer 100. In addition, the side of the second connecting sub-portion 312 away from the active material layer 20 is prone to impact and the like during the manufacturing and use of the battery monomer 100, which can generate metal debris, and the metal debris can fall between the first and second electrode plates 1 and 2, thereby causing short circuit of the battery monomer 100. In particular, the edge of the second solder print portion 512 away from the active material layer 20 is obtained by cutting, so that the side of the transition portion 1221 away from the first metal portion 121, the edge of the second solder print portion 512 away from the active material layer 20, and the side of the second connecting sub-portion 312 away from the active material layer 20 are flush, and large burrs can be generated on the side of the second connecting sub-portion 312 away from the active material layer 20, which can cause short circuit risk of the battery monomer 100.

[0398] By adopting the technical scheme of the embodiment, the second insulating portion 4122 can block burrs, metal debris, and the like on the side of the second connecting sub-portion 312 away from the active material layer 20, thereby reducing the risk of short circuit of the battery monomer 100, and facilitating improvement of the use reliability of the battery monomer 100.

[0399] In some embodiments, in the second direction, the opposite two side surfaces of the transition portion 1221 are flush with the opposite two side surfaces of the second connecting sub-portion 312, and the opposite two edges of the second solder print portion 512 are flush with the opposite two side surfaces of the second connecting sub-portion 312.

[0400] In the thickness direction of the current collector 10, the projections of the two side surfaces of the transition portion 1221 oppositely arranged in the second direction coincide with the projections of the two side surfaces of the second connecting sub-portion 312 oppositely arranged in the second direction, and the projections of the two edges of the second solder print portion 512 oppositely arranged in the second direction coincide with the projections of the two side surfaces of the second connecting sub-portion 312 oppositely arranged in the second direction. In the second direction, the second solder print portion 512 extends from one side edge of the second connecting sub-portion 312 to the other side edge of the second connecting sub-portion 312.

[0401] In some manufacturing processes of the first pole piece 1, the pole piece sheet has the welding marks arranged continuously along the second direction, and the pole piece sheet is cut at intervals along the second direction, so as to obtain the plurality of first pole pieces 1. In this process, the opposite two side surfaces of the transition part 1221 and the opposite two side surfaces of the second connecting sub-part 312 are cut to be flush with each other along the second direction, and the welding marks arranged continuously along the second direction are cut into a plurality of second welding mark parts 512, so that in the first pole piece 1 obtained by cutting, the opposite two edges of the second welding mark part 512 are flush with the opposite two side surfaces of the second connecting sub-part 312 along the second direction.

[0402] By adopting the technical scheme of this embodiment, the edge part structure of the first pole piece 1 is relatively regular along the second direction, which facilitates the processing and manufacturing of the first pole piece 1, reduces the redundancy of the second connecting sub-part 312 and the transition part 1221, saves space, and improves the energy density of the battery monomer 100. In addition, along the second direction, the size of the second welding mark part 512 is equal to the size of the transition part 1221, the first welding mark part 51 extends from one side surface of the transition part 1221 to the other side surface along the second direction, and the welding area between the transition part 1221 and the first connecting sub-part 311 is large, which is beneficial to improve the overcurrent capacity of the first pole piece 1 and improve the fast charging performance of the battery monomer 100.

[0403] In some embodiments, please refer to FIGS. 12-16, at least one of the opposite two side parts of the second insulation part 4122 protrudes from the corresponding side surface of the second connecting sub-part 312 along the second direction.

[0404] In the two side parts of the second insulation part 4122 distributed along the second direction, one side part protrudes from the side surface of the second connecting sub-part 312 on the same side, and the other side part protrudes or does not protrude from the other side surface of the second connecting sub-part 312.

[0405] In some manufacturing processes of the first pole piece 1, burrs may be generated on the side surface of the second connecting sub-part 312 along the second direction after the pole piece sheet is cut, thereby causing short circuit of the battery monomer 100. In particular, the second welding mark part 512 obtained by cutting causes large burrs on the side surface of the second connecting sub-part 312 along the second direction, thereby increasing the risk of short circuit of the battery monomer 100.

[0406] By adopting the technical scheme of this embodiment, the second insulation part 4122 can block the burrs on the side surface of the second connecting sub-part 312 along the second direction, thereby reducing the risk of short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0407] In some embodiments, referring to FIGS. 12-16, the second insulating portion 4122 protrudes from the side of the second connecting sub-portion 312 facing away from the active material layer 20 in the direction from the first metal portion 121 to the second metal portion 122.

[0408] In the thickness direction of the current collector 10, the projection of the side of the second connecting sub-portion 312 facing away from the active material layer 20 falls within the projection of the second insulating portion 4122.

[0409] In some examples, the protruding portion 1222 is covered with a first connecting sub-portion 311 connected between the second connecting portion 32 and the second connecting sub-portion 312, and the side of the first connecting sub-portion 311 facing away from the active material layer 20 can refer to the interface between the first connecting sub-portion 311 and the second connecting sub-portion 312, which can refer to the side of the transition portion 1221 facing away from the first metal portion 121, i.e., the side of the transition portion 1221 leading to the protruding portion 1222.

[0410] By adopting the technical solution of this embodiment, the second insulating portion 4122 can block burrs at the side of the second connecting sub-portion 312 facing away from the active material layer 20, reducing the risk of short circuit of the battery monomer 100.

[0411] In some embodiments, referring to FIGS. 12-16, the second insulating portion 4122 protrudes from the side of the second connecting sub-portion 312 facing the active material layer 20 in the direction from the second metal portion 122 to the first metal portion 121.

[0412] In the thickness direction of the current collector 10, the projection of the side of the second connecting sub-portion 312 facing the active material layer 20 falls within the projection of the second insulating portion 4122.

[0413] By adopting the technical solution of this embodiment, the second insulating portion 4122 can block burrs at the side of the second connecting sub-portion 312 facing the active material layer 20, reducing the risk of short circuit of the battery monomer 100.

[0414] In some embodiments, the second insulating portion 4122 protrudes from the side of the second connecting sub-portion 312 facing away from the active material layer 20 in the direction from the first metal portion 121 to the second metal portion 122, and protrudes from the side of the second connecting sub-portion 312 facing the active material layer 20 in the direction from the second metal portion 122 to the first metal portion 121.

[0415] In the thickness direction of the current collector 10, the projection of the second connecting sub-portion 312 falls within the projection of the second insulating portion 4122, which can cover the entire second connecting sub-portion 312 or the second welding mark portion 512 on the second connecting sub-portion 312.

[0416] By adopting the technical solutions of this embodiment, the second insulation part 4122 can realize the overall insulation of the second connecting sub-part 312, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0417] In some embodiments, referring to FIGS. 12-16, the first connecting part 31 includes at least one first connecting sub-part 311, the first connecting sub-part 311 is connected between the second connecting part 32 and the second connecting sub-part 312, the first connecting sub-part 311 covers the surface of the protruding part 1222 away from the insulation base 11, and the first connecting sub-part 311 corresponds to the protruding part 1222 one by one; the first insulation part 41 includes at least one first insulation part 4121, the first insulation part 4121 is connected with the second insulation part 4122, the first insulation part 4121 covers the surface of the first connecting sub-part 311 away from the protruding part 1222, and the first insulation part 4121 corresponds to the first connecting sub-part 311 one by one.

[0418] In some examples, the protruding structure of the second connecting sub-part 312 away from the side of the active material layer 20, the side of the second connecting sub-part 312 away from the active material layer 20 extends outwardly along the first direction to form the first connecting sub-part 311; the first sub-part 1211 is covered with the first insulation part 4121, the second insulation part 4122 is connected with the first insulation part 4121, and the interface between the first insulation part 4121 and the second insulation part 4122 can refer to the interface between the second connecting sub-part 312 and the first connecting sub-part 311 (see the dashed line N in FIG. 18).

[0419] By adopting the technical solutions of this embodiment, the first insulation part 4121 covers the first connecting sub-part 311, the second insulation part 4122 covers the second connecting sub-part 312, the first insulation part 4121 covers the first connecting sub-part 311 and the second connecting sub-part 312, the first insulation part 41 has a large coverage area, the insulation effect of the first insulation part 41 is good, the short circuit risk of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0420] In some embodiments, the number of protruding parts 1222 is multiple, and the multiple protruding parts 1222 are arranged at intervals along the second direction; the number of first connecting sub-parts 311 is multiple, and the multiple first connecting sub-parts 311 are arranged at intervals along the second direction; the number of second connecting parts 32 is multiple, and the multiple second connecting parts 32 are arranged at intervals along the second direction; the first connecting sub-part 311 is connected with the second connecting part 32 one by one, and the multiple first connecting sub-parts 311 are connected to one side of the second connecting sub-part 312 away from the active material layer 20; the second connecting sub-part 312 is arranged continuously along the second direction.

[0421] By adopting the technical scheme of this embodiment, the second connecting sub-parts 312 are arranged continuously along the second direction, the plurality of first connecting sub-parts 311 can be connected as a whole, the second connecting sub-parts 312 can play a good supporting role on the first connecting sub-parts 311, the risk of the first connecting sub-parts 311 bending to be inserted between the first and second pole pieces 1 and 2 can be reduced, the short circuit risk of the battery monomer 100 can be reduced, and the use reliability of the battery monomer 100 is improved; in addition, along the second direction, the size of the second connecting sub-parts 312 is large, which is beneficial to improve the welding area between the second connecting sub-parts 312 and the transition part 1221, improve the overcurrent capacity of the connection between the first connecting part 31 and the transition part 1221, improve the overcurrent capacity of the first pole piece 1, and improve the fast charging performance and use reliability of the battery monomer 100.

[0422] In some embodiments, referring to FIG. 5, the electrode assembly 101 further includes a second pole piece 2 opposite in polarity to the first pole piece 1, the second pole piece 2 includes a main functional part 210 arranged along a first direction and a tab part 220, the main functional part 210 has a first end face 2101 close to an end of the second metal part 122, and the tab part 220 extends outward from the first end face 2101; along a direction of the first metal part 121 towards the second metal part 122, a side of the second connecting sub-part 312 away from the active material layer 20 does not protrude the first end face 2101.

[0423] The main functional part 210 can refer to a main structure of the second pole piece 2, and the tab part 220 can refer to a protruding structure extending from an end of the main functional part 210 close to the second metal part 122, the tab part 220 is used for electrical connection with the electrode lead-out part 2011, and the conductive member 30 and the tab part 220 are electrically connected to the electrode lead-out parts 2011 different in polarity to realize charging and discharging of the battery monomer 100.

[0424] Among two end faces of the main functional part 210 relatively distributed along the first direction, one end face close to the second metal part 122 forms the first end face 2101.

[0425] Along a thickness direction of the current collector 10, a projection of the side of the second connecting sub-part 312 away from the active material layer 20 falls within a projection range of the main functional part 210, so that the first end face 2101 is arranged opposite to the hollow area of the conductive member 30 which does not extend out of the second connecting part 32 or the first connecting sub-part 311.

[0426] By adopting the technical scheme of this embodiment, the first end face 2101 is arranged opposite to the hollow area of the conductive member 30, which can reduce the short circuit risk of the battery monomer 100, and is beneficial to improve the use reliability of the battery monomer 100.

[0427] In some embodiments, referring to FIG. 5, along the thickness direction of the current collector 10, the projection of the first end surface 2101 is located within the projection of the second connecting sub-portion 312.

[0428] In the direction of the first metal portion 121 toward the second metal portion 122, the second connecting sub-portion 312 protrudes the first end surface 2101 away from the side of the active material layer 20, so that the side of the second connecting sub-portion 312 facing away from the active material layer 20 is not arranged opposite to the main functional portion 210, which can reduce the risk of short circuit of the battery monomer 100 and is conducive to improving the use reliability of the battery monomer 100.

[0429] In some embodiments, referring to FIGS. 12-16, along the direction of the first metal portion 121 toward the second metal portion 122, the first insulating piece 41 protrudes the edge of the first solder print 51 away from the active material layer 20.

[0430] Along the thickness direction of the current collector 10, the projection of the edge of the first solder print 51 away from the active material layer 20 is located within the projection range of the first insulating piece 41, and the first insulating piece 41 can cover the edge of the first solder print 51 away from the active material layer 20.

[0431] In some examples, the first solder print 51 includes a first solder print portion 511, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the first solder print portion 511 away from the active material layer 20.

[0432] In some examples, the first solder print 51 includes a second solder print portion 512, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the second solder print portion 512 away from the active material layer 20.

[0433] In some examples, the first solder print 51 includes a first solder print portion 511 and a second solder print portion 512, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the first solder print portion 511 away from the active material layer 20.

[0434] In some examples, the first solder print 51 includes a first solder print portion 511 and a second solder print portion 512, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the second solder print portion 512 away from the active material layer 20.

[0435] By adopting the technical scheme of this embodiment, the first insulating piece 41 can cover the edge of the first solder print 51 away from the active material layer 20, block the burr at the edge of the first solder print 51 away from the active material layer 20, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0436] In some embodiments, referring to FIGS. 12-16, the first insulating member 41 protrudes from the first solder print 51 away from the edge of the active material layer 20 in a direction from the first metal portion 121 to the second metal portion 122.

[0437] In the thickness direction of the current collector 10, the projection of the edge of the first solder print 51 near the active material layer 20 is within the projection range of the first insulating member 41, and the first insulating member 41 can cover the edge of the first solder print 51 near the active material layer 20.

[0438] In some examples, the first solder print 51 includes a first solder print portion 511, and the edge of the first solder print 51 near the active material layer 20 can refer to the edge of the first solder print portion 511 near the active material layer 20.

[0439] In some examples, the first solder print 51 includes a second solder print portion 512, and the edge of the first solder print 51 near the active material layer 20 can refer to the edge of the second solder print portion 512 near the active material layer 20.

[0440] In some examples, the first solder print portion 511 includes the first solder print portion 511 and the second solder print portion 512, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the second solder print portion 512 near the active material layer 20.

[0441] In some examples, the first solder print portion 511 includes the first solder print portion 511 and the second solder print portion 512, and the edge of the first solder print 51 away from the active material layer 20 can refer to the edge of the first solder print portion 511 near the active material layer 20.

[0442] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edge of the first solder print 51 near the active material layer 20, block the burr at the edge of the first solder print 51 near the active material layer 20, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0443] In some embodiments, referring to FIGS. 12-16, the first insulating member 41 protrudes from the first solder print 51 away from the edge of the active material layer 20 in a direction from the first metal portion 121 to the second metal portion 122; and the first insulating member 41 protrudes from the first solder print 51 near the edge of the active material layer 20 in a direction from the second metal portion 122 to the first metal portion 121.

[0444] In some examples, in the thickness direction of the current collector 10, the projection of the first solder print 51 is within the projection range of the first insulating member 41, and the first insulating member 41 can cover the entire first solder print 51.

[0445] By adopting the technical scheme of the embodiment, the coverage area of the first insulating part 41 is increased, the short circuit risk of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0446] In some embodiments, as shown in FIGS. 12-16, along the direction in which the first metal part 121 points to the second metal part 122, the first insulating part 41 protrudes from the side of the first connecting part 31 away from the active material layer 20.

[0447] Along the thickness direction of the current collector 10, the projection of the side of the first connecting part 31 away from the active material layer 20 falls within the projection range of the first insulating part 41, and the first insulating part 41 can cover the second connecting part 32.

[0448] In some examples, the first connecting part 31 only includes the first connecting subpart 311, and the side of the first connecting part 31 away from the active material layer 20 can refer to the side of the first connecting subpart 311 away from the active material layer 20.

[0449] In some examples, the first connecting part 31 only includes the second connecting subpart 312, and the side of the first connecting part 31 away from the active material layer 20 can refer to the side of the second connecting subpart 312 away from the active material layer 20.

[0450] In some examples, the first connecting part 31 includes the first connecting subpart 311 and the second connecting subpart 312, the first connecting subpart 311 is connected between the second connecting subpart 312, and the side of the first connecting part 31 away from the active material layer 20 can refer to the side of the first connecting subpart 311 away from the active material layer 20.

[0451] In some examples, the first connecting part 31 includes the first connecting subpart 311 and the second connecting subpart 312, the first connecting subpart 311 is connected between the second connecting subpart 312, and the side of the first connecting part 31 away from the active material layer 20 can refer to the side of the second connecting subpart 312 away from the active material layer 20.

[0452] By adopting the technical scheme of the embodiment, the first insulating part 41 can extend from the first welding mark 51 to the second connecting part 32, the coverage area of the first insulating part 41 is increased, the insulation effect of the first insulating part 41 is improved, the short circuit risk of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0453] In some embodiments, as shown in FIGS. 12-16, along the direction in which the first metal part 121 points to the second metal part 122, the first insulating part 41 protrudes from the side of the first connecting part 31 away from the active material layer 20.

[0454] In the thickness direction of the current collector 10, the side of the first connecting portion 31 close to the active material layer 20 falls within the projection range of the first insulating member 41, and the first insulating member 41 can cover the portion of the metal layer 12 between the first connecting portion 31 and the active material layer 20, or even the active material layer 20.

[0455] In some examples, the first connecting portion 31 only includes the first connecting sub-portion 311, and the side of the first connecting portion 31 close to the active material layer 20 can refer to the side of the first connecting sub-portion 311 close to the active material layer 20.

[0456] In some examples, the first connecting portion 31 only includes the second connecting sub-portion 312, and the side of the first connecting portion 31 close to the active material layer 20 can refer to the side of the second connecting sub-portion 312 close to the active material layer 20.

[0457] In some examples, the first connecting portion 31 includes the first connecting sub-portion 311 and the second connecting sub-portion 312, and the first connecting sub-portion 311 is connected between the second connecting sub-portion 312, and the side of the first connecting portion 31 close to the active material layer 20 can refer to the side of the second connecting sub-portion 312 close to the active material layer 20.

[0458] In some examples, the first connecting portion 31 includes the first connecting sub-portion 311 and the second connecting sub-portion 312, and the first connecting sub-portion 311 is connected between the second connecting sub-portion 312, and the side of the first connecting portion 31 close to the active material layer 20 can refer to the side of the first connecting sub-portion 311 close to the active material layer 20.

[0459] By adopting the technical scheme of this embodiment, the first insulating member 41 can cover the side of the first connecting portion 31 close to the active material layer 20, block burrs at this side, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0460] In some embodiments, as shown in FIGS. 12-16, in the direction of the first metal portion 121 pointing to the second metal portion 122, the first insulating member 41 protrudes from the side of the first connecting portion 31 away from the active material layer 20, and in the direction of the second metal portion 122 pointing to the first metal portion 121, the first insulating member 41 protrudes from the side of the first connecting portion 31 close to the active material layer 20.

[0461] In some examples, in the thickness direction of the current collector 10, the projection of the first connecting portion 31 falls within the projection range of the first insulating member 41, and the first insulating member 41 can cover the entire first connecting portion 31 or completely cover the first welding mark 51 on the first connecting portion 31.

[0462] By adopting the technical scheme of the embodiment, the first insulating piece 41 can cover the entire first connecting portion 31, the coverage area of the first insulating piece 41 is increased, the short circuit risk of the battery monomer 100 is reduced, and the use reliability of the battery monomer 100 is improved.

[0463] In some embodiments, referring to FIG. 7, along the first direction, the first welding mark 51 is spaced apart from the active material layer 20.

[0464] Along the thickness direction of the current collector 10, the projection of the first welding mark 51 does not coincide with the projection of the active material layer 20.

[0465] In some examples, the first pole piece 1 is a positive pole piece, and a gap exists between the first welding mark 51 and the active material layer 20. The gap can be used to provide a spacing space between the first connecting portion 31 and the active material layer 20, so as to reduce the risk of lithium precipitation caused by the contact between the first connecting portion 31 and the active material layer 20. In addition, the gap can also provide a spacing space for the side of the first welding mark 51 and the first connecting portion 31 close to the active material layer 20, so that the first welding mark 51 does not extend to the side of the first connecting portion 31 close to the active material layer 20, reducing the risk of being welded through or cracked at the side of the first connecting portion 31 close to the active material layer 20, and facilitating the reduction of burrs, metal debris and other components generated by welding, thereby improving the use reliability of the battery monomer 100.

[0466] In some examples, the first pole piece 1 is a negative pole piece, and a gap exists between the first welding mark 51 and the active material layer 20. The gap can provide a spacing space for the side of the first welding mark 51 and the first connecting portion 31 close to the active material layer 20, so that the first welding mark 51 does not extend to the side of the first connecting portion 31 close to the active material layer 20, reducing the risk of being welded through or cracked at the side of the first connecting portion 31 close to the active material layer 20, and facilitating the reduction of burrs, metal debris and other components generated by welding, thereby improving the use reliability of the battery monomer 100. The first connecting portion 31 can be in contact with the active material layer 20 or be spaced apart from the active material layer 20.

[0467] By adopting the technical scheme of the embodiment, the gap between the first welding mark 51 and the active material layer 20 makes the welding of the first connecting portion 31 and the metal layer 12 not welded to the active material layer 20, reducing the risk of false welding of the first connecting portion 31 and the metal layer 12, and improving the use reliability of the battery monomer 100.

[0468] In some embodiments, referring to FIG. 7, the electrode assembly 101 further comprises a second insulating piece 42, the second insulating piece 42 covers the surface of the second metal portion 122 away from the insulating base body 11, and the second insulating piece 42 is located between the first welding mark 51 and the active material layer 20.

[0469] The second insulating member 42 can be a component made of an insulating material, such as polypropylene (PP), polyethylene terephthalate (PET), or the like. The second insulating member 42 can be, but is not limited to, an insulating coating, an insulating adhesive (e.g., a hot melt adhesive), or an insulating adhesive tape.

[0470] The second insulating member 42 covers the portion of the metal layer 12 between the first welding mark 51 and the active material layer 20.

[0471] In some examples, a portion of the second insulating member 42 is located between the first connecting portion 31 and the metal layer 12, and another portion of the second insulating member 42 is located between the first connecting portion 31 and the active material layer 20; or the entire second insulating member 42 is located between the first connecting portion 31 and the active material layer 20.

[0472] By adopting the technical solution of this embodiment, the second insulating member 42 covers the portion of the metal layer 12 between the first welding mark 51 and the active material layer 20, which can achieve insulation of this portion and is conducive to reducing the risk of short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0473] In some embodiments, as shown in FIG. 7, along the first direction, the first connecting portion 31 is spaced apart from the active material layer 20.

[0474] Along the thickness direction of the current collector 10, the projection of the first connecting portion 31 does not coincide with the projection of the active material layer 20.

[0475] By adopting the technical solution of this embodiment, the first connecting portion 31 is not in contact with the active material layer 20, which can reduce mutual influence between the two and is conducive to improving the performance of the battery monomer 100.

[0476] In some embodiments, as shown in FIG. 7, at least a portion of the second insulating member 42 is located between the first connecting portion 31 and the active material layer 20.

[0477] A portion of the second insulating member 42 is located between the first connecting portion 31 and the active material layer 20, or the entire second insulating member 42 is located between the first connecting portion 31 and the active material layer 20.

[0478] In some examples, the first connecting portion 31 only includes the first connecting sub-portion 311, along the first direction, the first connecting sub-portion 311 is spaced apart from the transition portion 1221, and the second insulating member 42 can cover the portion of the protruding portion 1222 close to the transition portion 1221, the transition portion 1221, or both the portion of the protruding portion 1222 close to the transition portion 1221 and the transition portion 1221.

[0479] In some examples, the first connecting portion 31 includes a first connecting sub-portion 311 and a second connecting sub-portion 312, and the second insulating member 42 covers the transition portion 1221 and is located between the second connecting sub-portion 312 and the active material layer 20.

[0480] In some battery monomers 100, the second connecting portion 32 is connected to the electrode lead-out portion 2011 after being bent, and the second metal portion 122 is bent during the process of bending the second connecting portion 32, which may cause cracks in the part of the second metal portion 122 located between the first connecting portion 31 and the active material layer 20. The second insulating member 42 covers the part of the second metal portion 122 located between the first connecting portion 31 and the active material layer 20, and the second insulating member 42 can support this part, thereby reducing the risk of cracks in this part. In addition, the second insulating member 42 covers the part of the second metal portion 122 located between the first connecting portion 31 and the active material layer 20, which can also achieve insulation of this part, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0481] In some embodiments, referring to FIG. 5, the electrode assembly 101 further includes a second pole piece 2 opposite to the first pole piece 1 in polarity, and the second pole piece 2 includes a main functional portion 210 arranged along the first direction and a tab portion 220, the main functional portion 210 has a first end face 2101 near an end of the second metal portion 122, and the tab portion 220 extends outward from the first end face 2101; along the thickness direction of the current collector 10, the projection of the first end face 2101 is located within the projection of the second insulating member 42.

[0482] By adopting the technical scheme of this embodiment, the first end face 2101 is arranged opposite to the second insulating member 42, and the second insulating member 42 can block burrs at the first end face 2101, thereby reducing the risk of short circuit of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0483] In some embodiments, referring to FIG. 7, along the first direction, one side of the first insulating member 41 covers the first welding mark 51, and the other side of the first insulating member 41 covers at least part of the second insulating member 42.

[0484] Along the thickness direction of the current collector 10, the projection of the first insulating member 41 partially overlaps with the projection of the second insulating member 42.

[0485] The first insulating member 41 can cover part of the second insulating member 42, or cover the entire second insulating member 42.

[0486] In some examples, the first insulation member 41 can be fixed to the second insulation member 42 by means of adhesion or static adsorption. Of course, in other examples, the first insulation member 41 can also be fixed to the second insulation member 42 by other means.

[0487] By adopting the technical solutions of this embodiment, the first insulation member 41 and the second insulation member 42 can realize double-layer insulation, reduce the risk of short circuit of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0488] In some examples, referring to FIG. 7, the second insulation member 42 includes a first phase change heat storage layer, and the first phase change heat storage layer covers the surface of the second metal part 122 away from the insulation base 11.

[0489] The second insulation member 42 includes the first phase change heat storage layer or other layer structures. For example, the second insulation member 42 includes a second insulation base layer and a second adhesive layer, and the first phase change heat storage layer is connected between the second insulation base layer and the second adhesive layer. The second adhesive layer is bonded between the second metal part 122 and the first phase change heat storage layer. The second insulation base layer and the second adhesive layer can support the first phase change heat storage layer, so as to maintain the stable structure of the second insulation member 42 and reduce the risk of falling off of the second insulation member 42.

[0490] The second insulation member 42 only includes the first phase change heat storage layer, that is, the second insulation member 42 is the first phase change heat storage layer.

[0491] The first phase change heat storage layer can be a layer structure made of a phase change heat storage material. The phase change heat storage material is a kind of material that can store and release a large amount of heat energy through phase change (such as from solid to liquid or from liquid to gas) within a specific temperature range. The latent heat absorbed or released by such material during phase change is much greater than the heat stored by them through heat conduction or convection within the same temperature range. The phase change heat storage material can have stable properties of not reacting with the electrolyte and not dissolving, so that the second phase change heat storage layer 4113 can stably play a role in the battery monomer 100. The phase change heat storage material can be, but is not limited to, fatty acid, paraffin, nitrate, carbonate, etc.

[0492] In the charging and discharging process of the battery monomer 100, the second metal part 122 is easy to heat, and the temperature of the second metal part 122 rises, which may increase the risk of cracks and fractures of the second metal part 122, and affect the electron transport capacity of the second metal part 122.

[0493] By adopting the technical solutions of the embodiment, in the charging and discharging process of the battery monomer 100, the first phase change heat storage layer can absorb the heat of the second metal part 122, reduce the temperature of the second metal part 122, reduce the risk of cracks and fractures of the second metal part 122, and help improve the electron transport capability of the second metal part 122 and the fast charging performance and use reliability of the battery monomer 100.

[0494] In some embodiments, the material of the first phase change heat storage layer includes at least one of an organic heat storage material and an inorganic heat storage material.

[0495] In some examples, the material of the first phase change heat storage layer includes an organic heat storage material, the first phase change heat storage layer is made of the organic heat storage material, the organic heat storage material has good cycle stability and thermal stability, which helps maintain the stable structure of the second insulating part 42, improve the stability of the second insulating part 42 fixed on the second metal part 122, reduce the risk of falling of the second insulating part 42, and improve the use reliability of the battery monomer 100.

[0496] In some examples, the material of the first phase change heat storage layer includes an inorganic heat storage material, the first phase change heat storage layer is made of the inorganic heat storage material, and the inorganic heat storage material has strong heat storage capacity, which helps reduce the temperature of the second metal part 122, improve the use reliability of the battery monomer 100, and in addition, the inorganic heat storage material has low cost, which helps reduce the manufacturing cost of the battery monomer 100.

[0497] In some examples, the material of the first phase change heat storage layer includes an organic heat storage material and an inorganic heat storage material.

[0498] By adopting the technical solutions of the embodiment, the first phase change heat storage layer can have the performance of both the organic heat storage material and the inorganic heat storage material, which helps improve the performance and use reliability of the battery monomer 100.

[0499] In some embodiments, the material of the first phase change heat storage layer includes an organic heat storage material, and the organic heat storage material includes at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

[0500] The organic heat storage material can include one or more of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance; for example, some of these materials can maintain a stable structure below 200°C.

[0501] By adopting the technical scheme of the embodiment, the organic heat storage material adopts the above material, in the charging and discharging process of the battery monomer 100, the first phase change heat storage layer can better absorb the heat of the second metal part 122, reduce the temperature of the second metal part 122, and improve the use reliability of the battery monomer 100; in addition, the first phase change heat storage layer can also maintain a stable structure form, reduce the risk of falling off of the second insulating part 42, and is beneficial to improve the use reliability of the battery monomer 100.

[0502] In some embodiments, the material of the first phase change heat storage layer includes an inorganic heat storage material, and the inorganic heat storage material includes at least one of nitrate, carbonate, fluoride and hydrochloride.

[0503] The inorganic heat storage material includes one or more of nitrate, carbonate, fluoride and hydrochloride, for example: some of these materials can maintain a stable structure form in the range of 200-900 DEG C.

[0504] By adopting the technical scheme of the embodiment, the inorganic heat storage material adopts the above material, in the charging and discharging process of the battery monomer 100, the first phase change heat storage layer can better absorb the heat of the second metal part 122, reduce the temperature of the second metal part 122, and improve the use reliability of the battery monomer 100; in addition, the first phase change heat storage layer can also maintain a stable structure form, reduce the risk of falling off of the second insulating part 42, and is beneficial to improve the use reliability of the battery monomer 100.

[0505] In some embodiments, please refer to FIG. 17, along the first direction, one side of the first insulating part 41 covers the first solder print 51, and the other side of the first insulating part 41 covers the active material layer 20.

[0506] It can be understood that, among the two sides of the first insulating part 41 distributed along the first direction, one side covers the first solder print 51, and the other side covers at least part of the active material layer 20, wherein the first insulating part 41 can cover the end of the active material layer 20 towards the first connecting part 31, or can cover the entire active material layer 20.

[0507] Along the first direction, the first insulating part 41 extends from the first solder print 51 to the active material layer 20, so that the metal layer 12 and the first connecting part 31 located between the first solder print 51 and the active material layer 20 are covered by the first insulating part 41. Among them, the part of the metal layer 12 located between the first solder print 51 and the active material layer 20 can be covered with the second insulating part 42, or can not be covered with the second insulating part 42.

[0508] In some examples, the part of the metal layer 12 located between the first solder print 51 and the active material layer 20 can be covered with the second insulating part 42, and the first insulating part 41 can completely cover the second insulating part 42.

[0509] In some examples, the portion of the metal layer 12 between the first solder joint 51 and the active material layer 20 can not be covered by the second insulating member 42, and the first insulating member 41 extends from the first solder joint 51 to the active material layer 20, so as to cover the portion of the metal layer 12 between the first connecting portion 31 and the active material layer 20, insulate this portion, and improve the use reliability of the battery monomer 100. In addition, the second insulating member 42 can be omitted to save costs, and the active material layer 20 can be used to cover the position of the original second insulating member 42, so as to increase the coverage area of the active material layer 20 on the metal layer 12, and improve the energy density of the battery monomer 100.

[0510] By adopting the technical scheme of the embodiment, the first insulating member 41 extends from the first solder joint 51 to the active material layer 20, the coverage area of the first insulating member 41 is wide, the insulation effect is good, and the use reliability of the battery monomer 100 is improved. The first insulating member 41 can cover the end of the active material layer 20 close to the second metal portion 122, block the burr of the active material layer 20 close to the second metal portion 122, reduce the short circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0511] In some embodiments, please refer to FIG. 7, the number of metal layers 12 is two, the two metal layers 12 cover opposite sides of the insulating substrate 11 along the thickness direction of the current collector 10, the number of active material layers 20 is two, the two active material layers 20 cover the first metal portions 121 of the two metal layers 12 respectively; the number of conductive members 30 is two, the first connecting portions 31 of the two conductive members 30 are respectively soldered to the second metal portions 122 of the two metal layers 12 and form two first solder joints 51; the number of first insulating members 41 is two, the two first insulating members 41 cover the two first solder joints 51 respectively.

[0512] The number of metal layers 12, the number of first insulating members 41, the number of active material layers 20, and the number of conductive members 30 are all two, the two metal layers 12 cover opposite sides of the insulating substrate 11 along the thickness direction respectively, the two active material layers 20 cover the first metal portions 121 of the two metal layers 12 respectively; the first connecting portion 31 of one conductive member 30 is soldered to the second metal portion 122 of one metal layer 12 away from the surface of the insulating substrate 11 and forms one first solder joint 51, the first connecting portion 31 of the other conductive member 30 is soldered to the second metal portion 122 of the other metal layer 12 away from the surface of the insulating substrate 11 and also forms one first solder joint 51, and the two first insulating members 41 are located on opposite sides of the insulating substrate 11 along the thickness direction and cover the two first solder joints 51 respectively.

[0513] By adopting the technical scheme of the embodiment, the first connecting portions 31 of the two conductive members 30 are welded with the metal layers 12 located on the opposite sides of the insulating base body 11, so that the second connecting portions 32 of the two conductive members 30 are connected, thereby electrically connecting the two metal layers 12, breaking the insulation limitation of the insulating base body 11, effectively improving the conductive capacity of the first pole piece 1, improving the fast charging performance of the battery monomer 100, reducing the heating risk of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0514] In some embodiments, referring to FIG. 18, along the direction of the first metal portion 121 pointing to the second metal portion 122, the part of the first insulating member 41 protruding from the metal layer 12 forms a blocking portion 4131, and along the second direction, the blocking portion 4131 is located on the side of the second connecting portion 32, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0515] The blocking portion 4131 can refer to the part of the first insulating member 41 protruding from the side of the metal layer 12 away from the active material layer 20, and the blocking portion 4131 is located on one side of the second connecting portion 32 along the second direction.

[0516] In some examples, along the thickness direction of the current collector 10, the blocking portion 4131 can refer to the part of the first insulating member 41 located outside the projection of the metal layer 12.

[0517] In some examples, the first connecting portion 31 only includes a first connecting sub-portion 311, along the first direction, one side of the first insulating member 41 can cover the first metal portion 121, and the other side of the first insulating member 41 covers the first welding mark portion 511 on the first connecting sub-portion 311, along the direction of the first metal portion 121 pointing to the second metal portion 122, the first insulating member 41 protrudes from the first metal portion 121 and forms a blocking portion 4131 corresponding to the region of the first metal portion 121 where the protruding portion 1222 is not led out; during the production or use of the battery monomer 100, the region of the first metal portion 121 where the protruding portion 1222 is not led out can generate burrs, metal debris and other components, thereby increasing the short circuit risk of the battery monomer 100, and the blocking portion 4131 can block the burrs, metal debris and other components in these regions, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0518] In some examples, the first connecting part 31 includes a first connecting sub-part 311 and a second connecting sub-part 312, the first insulating part 41 covers the first connecting sub-part 311 and the second connecting sub-part 312, and in the direction from the first metal part 121 to the second metal part 122, the first insulating part 41 protrudes from the second connecting sub-part 312 and forms a blocking part 4131 corresponding to the part of the second connecting sub-part 312 that does not lead to the first connecting sub-part 311. During the production or use of the battery monomer 100, the part of the second connecting sub-part 312 that does not lead to the first connecting sub-part 311 may generate burrs, metal debris and other components, which increases the short circuit risk of the battery monomer 100, and the blocking part 4131 can block the burrs, metal debris and other components in these areas, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0519] By adopting the technical scheme of this embodiment, the blocking part 4131 can block the burrs, metal debris and other components at the edge of the metal layer 12, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0520] In some embodiments, as shown in FIG. 18, the blocking parts 4131 of the two first insulating parts 41 are attached.

[0521] In the thickness direction of the current collector 10, the two first insulating parts 41 are located on opposite sides of the first electrode tab 1, and the blocking parts 4131 of the two first insulating parts 41 are staggered with the protruding part 1222 of the metal layer 12, so that the blocking parts 4131 of the two first insulating parts 41 can be directly attached, wherein the blocking parts 4131 of the two first insulating parts 41 can be attached by means of adhesion or static adsorption, but are not limited thereto.

[0522] By adopting the technical scheme of this embodiment, after the blocking parts 4131 of the two first insulating parts 41 are attached, the burrs, metal debris and other components at the edge of the metal layer 12 can be wrapped, thereby reducing the risk of metal debris falling and reducing the short circuit risk of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0523] In some embodiments, as shown in FIG. 7, the second connecting parts 32 of the two conductive members 30 are welded and form second welding marks 52.

[0524] In some examples, in the direction from the first metal part 121 to the second metal part 122, the conductive member 30 protrudes from the part of the protruding part 1222 away from the side surface of the active material layer 20 to form the second connecting part 32, so that the second connecting parts 32 of the two conductive members 30 can be directly close to each other and thus welded together, and the traces left by welding are the second welding marks 52. The second connecting parts 32 of the two conductive members 30 can be welded by ultrasonic welding, laser welding or the like.

[0525] By adopting the technical scheme of this embodiment, the second connecting part 32 of the two conductive members 30 can be welded to electrically connect the metal layer 12 on the opposite sides of the insulating base body 11, thereby breaking the insulation limitation of the insulating base body 11, effectively improving the conductive capacity of the first tab 1, improving the fast-charging performance of the battery monomer 100, reducing the heat production of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0526] In some embodiments, referring to FIG. 7, the first insulating member 41 covers at least part of the second welding mark 52.

[0527] The first insulating member 41 can cover part of the second welding mark 52, and the first insulating member 41 can also cover the entire second welding mark 52.

[0528] By adopting the technical scheme of this embodiment, the first insulating member 41 can cover the second welding mark 52, block the components such as the sharp protrusions and metal debris on the second welding mark 52, reduce the short-circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0529] In some embodiments, along the direction of the first metal part 121 towards the second metal part 122, the first insulating member 41 protrudes from the edge of the second welding mark 52 away from the active material layer 20.

[0530] Among the two edges of the second welding mark 52 relatively distributed along the first direction, the edge away from the active material layer 20 is the edge of the second welding mark 52 away from the active material layer 20.

[0531] Along the thickness direction of the current collector 10, the projection of the second welding mark 52 falls within the projection of the first insulating member 41, so that the first insulating member 41 can completely cover the second welding mark 52.

[0532] By adopting the technical scheme of this embodiment, the first insulating member 41 can cover the entire second welding mark 52, block the components such as burrs and metal debris on the second welding mark 52, reduce the short-circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0533] In some embodiments, referring to FIG. 5, the electrode assembly 101 further includes a second tab 2 opposite in polarity to the first tab 1, the second tab 2 includes a main functional part 210 and a tab part 220 arranged along the first direction, the main functional part 210 has a first end face 2101 at the end part close to the second metal part 122, and the tab part 220 extends outward from the first end face 2101; along the thickness direction of the current collector 10, the projection of the first end face 2101 falls within the projection of the first insulating member 41.

[0534] In some examples, the first insulating member 41 includes a first insulating portion 4121, a projection of the first end surface 2101 is located within a projection of the first insulating portion 4121 along a thickness direction of the current collector 10, the first end surface 2101 is arranged opposite to the first insulating portion 4121, and the first insulating portion 4121 can block the pointed protrusion at the first end surface 2101, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0535] In some examples, the first insulating member 41 includes a second insulating portion 4122, a projection of the first end surface 2101 is located within a projection of the second insulating portion 4122 along a thickness direction of the current collector 10, the first end surface 2101 is arranged opposite to the second insulating portion 4122, and the second insulating portion 4122 can block the pointed protrusion at the first end surface 2101, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100. The projection of the first end surface 2101 can be located within a projection of the second connecting sub-portion 312 along the thickness direction of the current collector 10.

[0536] In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122, a projection of the first end surface 2101 is located within a projection of the first insulating portion 4121 along a thickness direction of the current collector 10, the first end surface 2101 is arranged opposite to the first connecting sub-portion 311, and along a direction in which the first metal portion 121 points to the second metal portion 122, the main body functional portion 210 protrudes the second connecting sub-portion 312 away from an edge of the active material layer 20; or, a projection of the first end surface 2101 is located within a projection of the second insulating portion 4122, the first end surface 2101 is arranged opposite to the second insulating portion 4122, and along a direction in which the first metal portion 121 points to the second metal portion 122, the main body functional portion 210 does not protrude a side of the second connecting sub-portion 312 away from the active material layer 20.

[0537] By adopting the technical scheme of the embodiment, the first insulating member 41 can block the pointed protrusion at the first end surface 2101, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0538] In some embodiments, the glass transition temperature of the first insulating member 41 is greater than or equal to 150°C.

[0539] The glass transition temperature can refer to a temperature at which a material changes from a glass state to a high-elasticity state; when the temperature is lower than the glass transition temperature, the first insulating member 41 has a stable structure form; when the temperature is higher than the glass transition temperature, the first insulating member 41 melts. The higher the glass transition temperature of the first insulating member 41, the better the high-temperature resistance of the first insulating member 41, and the better the structure stability of the first insulating member 41 in a high-temperature environment.

[0540] The glass transition temperature of the first insulating member 41 can be measured according to the method described in GB / T 19466.1-2004.

[0541] In some examples, the glass transition temperature of the first insulating member 41 can be 150°C or any value greater than 150°C, for example, the glass transition temperature of the first insulating member 41 can be, but is not limited to, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 220°C, 250°C, 300°C, 350°C.

[0542] During the charging and discharging process of the battery monomer 100, heat may be generated at the first welding mark 51, the temperature at the first welding mark 51 may rise, which may cause the first insulating member 41 to melt, thereby exposing the burrs, metal debris and other components on the first welding mark 51, thereby increasing the short circuit risk of the battery monomer 100 and reducing the use reliability of the battery monomer 100.

[0543] By adopting the technical scheme of this embodiment, the glass transition temperature of the first insulating member 41 is greater than or equal to 150°C, so that the first insulating member 41 can maintain a stable structure during the charging and discharging process of the battery monomer 100, reducing the risk of melting of the first insulating member 41, reducing the risk of exposure of burrs, metal debris and other components on the first welding mark 51, reducing the short circuit risk of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0544] In some embodiments, the glass transition temperature of the first insulating member 41 is greater than or equal to 200°C.

[0545] By adopting the technical scheme of this embodiment, the glass transition temperature of the first insulating member 41 is greater than or equal to 200°C, so that the first insulating member 41 can better maintain a stable structure during the charging and discharging process of the battery monomer 100, the first insulating member 41 is not prone to melting, and the first insulating member 41 can stably block the burrs of the first welding mark 51, which is conducive to reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0546] In some embodiments, the specific heat capacity of the first insulating member 41 is greater than or equal to 1.2 J / g·℃.

[0547] Specific heat capacity refers to the heat absorbed (or released) by unit mass of a substance when the temperature rises (or falls) by 1°C. Specific heat capacity is an important thermal property of a substance, which reflects the ability of a substance to store heat energy. Under the condition that the temperature rise is constant, the greater the specific heat capacity of the substance, the more heat the substance absorbs.

[0548] The greater the specific heat capacity of the first insulating piece 41, the smaller the temperature rise of the first insulating piece 41 after absorbing more heat, so that the first insulating piece 41 exhibits better heat resistance.

[0549] The specific heat capacity of the first insulating piece 41 can be measured in the manner described in the national standard GB / T 5990-2021.

[0550] In some examples, the value of the specific heat capacity of the first insulating piece 41 can be 1.2 J / g·℃ or any value above 1.2 J / g·℃. For example, the value of the specific heat capacity of the first insulating piece 41 can be, but is not limited to, 1.2 J / g·℃, 1.5 J / g·℃, 2 J / g·℃, or 3 J / g·℃.

[0551] By adopting the technical solution of this embodiment, the design that the specific heat capacity of the first insulating piece 41 is greater than or equal to 1.2 J / g·℃ makes the first insulating piece 41 absorb heat at the first weld mark 51, reduces the temperature of the first weld mark 51, and the temperature rise of the first insulating piece 41 is small, reducing the risk of melting of the first insulating piece 41. The first insulating piece 41 can stably block the burrs of the first weld mark 51, reduce the short circuit risk of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0552] In some embodiments, the glass transition temperature of the first insulating piece 41 is greater than or equal to 150℃, and the specific heat capacity of the first insulating piece 41 is greater than or equal to 1.2 J / g·℃.

[0553] By adopting the technical solution of this embodiment, the design that the specific heat capacity of the first insulating piece 41 is greater than or equal to 1.2 J / g·℃ makes the first insulating piece 41 absorb heat at the first weld mark 51 and produce a small temperature rise. The design that the glass transition temperature of the first insulating piece 41 is greater than or equal to 150℃ makes the temperature of the first insulating piece 41 not easily exceed the glass transition temperature of the first insulating piece 41 after absorbing heat and rising in temperature, so that the first insulating piece 41 can maintain reliable mechanical strength and structural integrity. Thus, in the whole life cycle of the battery monomer 100, the first insulating piece 41 can effectively cover the burrs, metal debris and other components of the first weld mark 51, reduce the risk of insulation failure caused by heat at the first weld mark 51, and improve the use reliability of the battery monomer 100.

[0554] In some embodiments, referring to FIGS. 19-21, the first insulating piece 41 includes a first insulating base layer 4111 and a first adhesive layer 4112, and the first adhesive layer 4112 is bonded between the first weld mark 51 and the first insulating base layer 4111.

[0555] The first insulating element 41 adopts a tape structure; the first insulating base layer 4111 can refer to the main body of the first insulating element 41, and the first adhesive layer 4112 can refer to the structure formed by the adhesive covering the surface of the first insulating base layer 4111. The material of the first insulating base layer 4111 can be polyethylene terephthalate, polypropylene, etc. The material of the first adhesive layer 4112 can be acrylic, rubber, latex, etc. The first insulating base layer 4111 and the second insulating base layer can be the same or different. The first adhesive layer 4112 and the second adhesive layer can be the same or different.

[0556] In some battery cells 100, insulating adhesive (e.g., hot melt adhesive) can be applied to the first solder mark 51 to form the first insulating component 41. However, the coating operation may result in the risk of missed coating. In addition, the insulating adhesive needs to be applied thickly to cover the burrs, metal debris and other components on the first solder mark 51, which is not conducive to improving the volumetric energy density of the battery cell 100.

[0557] By adopting the technical solution of this embodiment, the first insulating component 41 adopts the structure of tape, which can directly attach the first insulating component 41 to the first solder mark 51, reducing the risk of incomplete coverage; the first insulating base layer 4111 and the first adhesive layer 4112 cover the first solder mark 51, blocking the burrs of the first solder mark 51. The thickness of the first insulating base layer 4111 and the thickness of the first adhesive layer 4112 do not need to be large, which is beneficial to improving the energy density of the battery cell 100; the first insulating base layer 4111 has good structural strength and can stably block the burrs of the first solder mark 51, improving the reliability of the battery cell 100; the first adhesive layer 4112 can stably fix the first insulating base layer 4111 to the first solder mark 51, reducing the risk of the first insulating component 41 falling off; the metal debris of the first solder mark 51 can also be adhered to the first adhesive layer 4112, which can effectively reduce the risk of metal debris falling off the first solder mark 51 and reduce the short circuit risk of the battery cell 100.

[0558] In some embodiments, as shown in Figures 19-21, the first insulating member 41 further includes a second phase change heat storage layer 4113, which is connected between the first insulating base layer 4111 and the first adhesive layer 4112, and the first adhesive layer 4112 is bonded between the second phase change heat storage layer 4113 and the first solder mark 51.

[0559] The second phase change thermal storage layer 4113 can refer to a component made of a phase change thermal storage material. The phase change thermal storage material can possess stable properties, such as not reacting with or dissolving in the electrolyte, allowing the second phase change thermal storage layer 4113 to function stably within the battery cell 100. The phase change thermal storage material can be, but is not limited to, fatty acids, paraffin wax, nitrates, carbonates, etc. The first phase change thermal storage layer and the second phase change thermal storage layer 4113 can be the same or different.

[0560] The insulating base 11, the second phase change heat storage layer 4113, and the first adhesive layer 4112 are stacked, the second phase change heat storage layer 4113 is connected between the insulating base 11 and the first adhesive layer 4112, and in the case where the first insulating member 41 covers the first solder print 51, the insulating base 11, the second phase change heat storage layer 4113, and the first adhesive layer 4112 are stacked in the thickness direction of the current collector 10, and the first adhesive layer 4112 is located between the first solder print 51 and the second phase change heat storage layer 4113.

[0561] By adopting the technical scheme of this embodiment, the second phase change heat storage layer 4113 can absorb heat at the first solder print 51 during phase change, reduce the temperature rise of the first insulating base layer 4111 and the first adhesive layer 4112, reduce the risk of melting of the first insulating base layer 4111 and the first adhesive layer 4112, and help maintain the structural stability of the first insulating member 41 and improve the use reliability of the battery monomer 100.

[0562] In some embodiments, the material of the second phase change heat storage layer 4113 includes at least one of an organic heat storage material and an inorganic heat storage material.

[0563] In some examples, the material of the second phase change heat storage layer 4113 includes an organic heat storage material, and the second phase change heat storage layer 4113 is made of the organic heat storage material. The organic heat storage material has good cycle stability and thermal stability, which helps maintain the stable structure of the first insulating member 41, improves the stability of the first insulating member 41 fixed on the first solder print 51, reduces the risk of falling off of the first insulating member 41, and improves the use reliability of the battery monomer 100.

[0564] In some examples, the material of the second phase change heat storage layer 4113 includes an inorganic heat storage material, and the second phase change heat storage layer 4113 is made of the inorganic heat storage material. The inorganic heat storage material has strong heat storage capacity, which helps reduce the temperature at the first solder print 51 and improve the use reliability of the battery monomer 100. In addition, the inorganic heat storage material has low cost, which helps reduce the manufacturing cost of the battery monomer 100.

[0565] In some examples, the material of the second phase change heat storage layer 4113 includes an organic heat storage material and an inorganic heat storage material.

[0566] By adopting the technical scheme of this embodiment, the second phase change heat storage layer 4113 can have the performance of both organic heat storage material and inorganic heat storage material, which helps improve the performance and use reliability of the battery monomer 100.

[0567] In some embodiments, the material of the second phase-change heat storage layer 4113 comprises an organic heat storage material, and the organic heat storage material comprises at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

[0568] The organic heat storage material can comprise one or more of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance; for example, some of these materials are capable of maintaining a stable structural morphology below 200°C.

[0569] By adopting the technical solution of this embodiment, the organic heat storage material adopts the above-mentioned material, and in the charging and discharging process of the battery monomer 100, the second phase-change heat storage layer 4113 can better absorb the heat at the first welding mark 51, reduce the temperature rise of the first insulating base layer 4111 and the first adhesive layer 4112, help the first insulating base layer 4111 maintain a stable structural morphology, and can stably block the burrs, metal debris and other components on the first welding mark 51, reduce the risk of falling of the first insulating piece 41, and improve the use reliability of the battery monomer 100.

[0570] In some embodiments, the material of the second phase-change heat storage layer 4113 comprises an inorganic heat storage material, and the inorganic heat storage material comprises at least one of a nitrate, a carbonate, a fluoride, and a hydrochloride.

[0571] By adopting the technical solution of this embodiment, the inorganic heat storage material adopts the above-mentioned material, and in the charging and discharging process of the battery monomer 100, the second phase-change heat storage layer 4113 can better absorb the heat at the first welding mark 51, reduce the temperature rise of the first insulating base layer 4111 and the first adhesive layer 4112, help the first insulating base layer 4111 maintain a stable structural morphology, and can stably block the burrs, metal debris and other components on the first welding mark 51, reduce the risk of falling of the first insulating piece 41, and improve the use reliability of the battery monomer 100.

[0572] In some embodiments, referring to FIGS. 19-21, the thickness of the second phase-change heat storage layer 4113 ranges from 1 μm to 5 μm.

[0573] The thickness of the second phase-change heat storage layer 4113 is T1, where 1 μm≤T1≤5 μm.

[0574] The value of T1 can be 1 μm, 5 μm, or any value between 1 μm and 5 μm; for example, the value of T1 can be, but is not limited to, 1 μm, 2 μm, 3 μm, 4 μm, or 5 μm.

[0575] By adopting the technical solutions of this embodiment, the design that the layer thickness of the second phase change heat storage layer 4113 is greater than or equal to 1 μm enables the second phase change heat storage layer 4113 to absorb heat at the first solder print 51, reduces the temperature at the first solder print 51, and is conducive to maintaining the mechanical strength and structural stability of the first insulating member 41 and improving the use reliability of the battery monomer 100; the design that the layer thickness of the second phase change heat storage layer 4113 is less than or equal to 5 μm is conducive to reducing the occupied space and weight of the phase change heat storage and improving the energy density of the battery monomer 100.

[0576] In some embodiments, the glass transition temperature of the first adhesive layer 4112 is greater than the phase change temperature of the second phase change heat storage layer 4113, and / or the glass transition temperature of the first insulating base layer 4111 is greater than the phase change temperature of the second phase change heat storage layer 4113.

[0577] The phase change temperature can refer to the phase change temperature in the heat absorption process, which generally refers to a specific temperature that needs to be absorbed in heat when a substance changes from one phase state to another phase state. The following are some common heat absorption phase change types and their corresponding phase change temperatures:

[0578] Melting: the heat needs to be absorbed when a solid melts into a liquid, and the phase change temperature is called the melting point.

[0579] Evaporation: the heat needs to be absorbed when a liquid evaporates into a gas, and the boiling point of the liquid can be regarded as an example of the heat absorption phase change temperature.

[0580] Sublimation: the heat needs to be absorbed when a solid sublimates directly into a gas, and the phase change temperature is called the sublimation point.

[0581] In some examples, the glass transition temperature of the first adhesive layer 4112 is greater than the phase change temperature of the second phase change heat storage layer 4113, and in the case of heat absorption phase change of the second phase change heat storage layer 4113, the first adhesive layer 4112 has a stable structural form, which is conducive to maintaining the mechanical strength, structural stability and adhesion of the first insulating member 41, so that the first insulating member 41 can be stably fixed to the first solder print 51, reducing the risk of insulation failure of the first insulating member 41, and improving the use reliability of the battery monomer 100.

[0582] In some examples, the glass transition temperature of the first insulating base layer 4111 is greater than the phase change temperature of the second phase change heat storage layer 4113, and in the case of heat absorption phase change of the second phase change heat storage layer 4113, the first insulating base layer 4111 is in a stable structural form, which is conducive to maintaining the mechanical strength and structural stability of the first insulating member 41 and reducing the risk of insulation failure of the first insulating member 41, and improving the use reliability of the battery monomer 100.

[0583] In some examples, the glass transition temperature of the first adhesive layer 4112 is greater than the phase transition temperature of the second phase change heat storage layer 4113, and the glass transition temperature of the first insulating base layer 4111 is greater than the phase transition temperature of the second phase change heat storage layer 4113; the glass transition temperature of the first insulating base layer 4111 is greater than the phase transition temperature of the second phase change heat storage layer 4113, and the first insulating base layer 4111 and the first adhesive layer 4112 are in a stable structural form in the case of endothermic phase transition of the second phase change heat storage layer 4113, which is conducive to maintaining the mechanical strength, structural stability and adhesion of the first insulating part 41, so that the first insulating part 41 can be stably fixed on the first solder print 51, reducing the risk of insulation failure of the first insulating part 41, and being conducive to improving the use reliability of the battery monomer 100.

[0584] By adopting the technical scheme of this embodiment, the mechanical strength and structural stability of the first insulating part 41 can be maintained, and the risk of insulation failure of the first insulating part 41 can be reduced, which is conducive to improving the use reliability of the battery monomer 100.

[0585] In some embodiments, the material of the first insulating base layer 4111 includes at least one of polypropylene, polyethylene terephthalate, aramid 1313, polyvinylidene fluoride and cellulose.

[0586] The material of the first insulating base layer 4111 includes one or more of polypropylene, polyethylene terephthalate, aramid 1313, polyvinylidene fluoride and cellulose.

[0587] By adopting the technical scheme of this embodiment, the first insulating base layer 4111 adopts the above-mentioned material, and in the charging and discharging process of the battery monomer 100, the first insulating base layer 4111 can maintain a stable structural form and is not prone to melting, the first insulating part 41 has good high-temperature resistance, and the use reliability of the battery monomer 100 is improved.

[0588] In some embodiments, the material of the first adhesive layer 4112 includes at least one of acrylic acid, ethylene acrylic acid copolymer, rubber and latex.

[0589] The material of the first adhesive layer 4112 includes one or more of acrylic acid, ethylene acrylic acid copolymer, rubber and latex.

[0590] By adopting the technical scheme of this embodiment, the first adhesive layer 4112 adopts the above-mentioned material, and in the charging and discharging process of the battery monomer 100, the first adhesive layer 4112 can maintain a stable structural form and is not prone to melting, the first insulating part 41 can be stably adhered to the first solder print 51, reducing the risk of falling off of the first insulating part 41, and the use reliability of the battery monomer 100 is improved.

[0591] In some embodiments, referring to FIGS. 19-21, the first adhesive layer 4112 has a thickness in a range from 1 μm to 7 μm.

[0592] The first adhesive layer 4112 has a thickness T2, where 1 μm≤T2≤7 μm.

[0593] The value of T2 can be 1 μm, 7 μm, or any value in a range from 1 μm to 7 μm; for example, but not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, or 7 μm.

[0594] By adopting the technical solution of this embodiment, the first adhesive layer 4112 has a thickness greater than or equal to 1 μm, which allows the first adhesive layer 4112 to stably bond the second phase change heat storage layer 4113 and the first solder print 51 together, reduces the risk of the first insulating member 41 falling off, and improves the use reliability of the battery monomer 100; the first adhesive layer 4112 has a thickness less than or equal to 7 μm, which reduces the risk of overflow of the first adhesive layer 4112.

[0595] In some embodiments, referring to FIGS. 19-21, the first insulating base layer 4111 has a thickness in a range from 1 μm to 10 μm.

[0596] The first insulating base layer 4111 has a thickness T3, where 1 μm≤T3≤10 μm.

[0597] The value of T3 can be 1 μm, 10 μm, or any value in a range from 1 μm to 10 μm; for example, but not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm.

[0598] By adopting the technical solution of this embodiment, the first insulating base layer 4111 has a thickness greater than or equal to 1 μm, which allows the first insulating base layer 4111 to better block burrs of the first solder print 51, and improves the use reliability of the battery monomer 100; the first insulating base layer 4111 has a thickness less than or equal to 10 μm, which reduces the occupied space and weight of the first insulating base layer 4111, and is conducive to improving the energy density of the battery monomer 100.

[0599] In some embodiments, referring to FIG. 7, the current collector 10 further includes a conductive protective layer 13, at least a portion of the conductive protective layer 13 is located between the active material layer 20 and the first metal portion 121.

[0600] In some examples, the conductive protective layer 13 can refer to a conductive structure arranged between the active material layer 20 and the first metal part 121, which can conduct electricity so that electrons can be transmitted between the active material layer 20 and the metal layer 12 to realize the input or output of electrical energy of the battery monomer 100. The conductive protective layer 13 can be an equal-thickness structure or a non-equal-thickness structure.

[0601] For example, part of the conductive protective layer 13 is located between the active material layer 20 and the first metal part 121, and the other part covers the transition part 1221 and protrudes out of the active material layer 20.

[0602] For example, the entire conductive protective layer 13 is located between the active material layer 20 and the first metal part 121.

[0603] In some examples, the conductive protective layer 13 can contain conductive carbon black and a binder, which can play a role in buffering and lubrication between the active material layer 20 and the metal layer 12, and can alleviate the damage of particles in the active material layer 20 to the metal layer 12 during the rolling process of the first electrode plate 1. On the other hand, the conductive carbon black can reduce the contact resistance between the particles in the active material layer 20 and the metal layer 12, which is conducive to improving the electron transmission capacity of the metal layer 12 and improving the fast-charging performance of the battery monomer 100.

[0604] During the rolling process of the first electrode plate 1, the thickness of the metal layer 12 is relatively thin, and the particles in the active material layer 20 can damage the metal layer 12, thereby causing the metal layer 12 to be prone to cracks and other problems. The conductive protective layer 13 of the present application can separate the active material layer 20 and the metal layer 12, and protect the metal layer 12, thereby reducing the risk of cracks in the metal layer 12 caused by rolling the active material layer 20, and improving the overcurrent capacity of the metal layer 12.

[0605] In some examples, as shown in FIG. 7, the conductive protective layer 13 protrudes from the end of the active material layer 20 close to the second metal part 122 along the direction from the first metal part 121 to the second metal part 122.

[0606] In some examples, part of the conductive protective layer 13 covers the first metal part 121, and the other part covers the transition part 1221. The conductive protective layer 13 protrudes out of the active material layer 20, and the conductive protective layer 13 can completely separate the metal layer 12 and the active material layer 20. In addition, it can also provide an extension space for the rolling process of the active material layer 20, which is conducive to reducing the risk of direct contact between the active material layer 20 and the metal layer 12.

[0607] By adopting the technical scheme of the embodiment, the conductive protective layer 13 can completely separate the active material layer 20 and the metal layer 12, the conductive protective layer 13 has better protection capability for the metal layer 12, the overcurrent capability of the first tab 1 is better, and the fast charging performance and use reliability of the battery monomer 100 are improved.

[0608] In some embodiments, referring to FIG. 7, the first metal part 121 has a thickness less than that of the second metal part 122 at least in part.

[0609] The minimum thickness of the first metal part 121 is t1, and the thickness of the second metal part 122 is t2, t1 < t2.

[0610] In some examples, the second metal part 122 has an equal thickness structure or a substantially equal thickness structure, the first metal part 121 also has an equal thickness structure or a substantially equal thickness structure, and the thickness of the second metal part 122 is greater than the minimum thickness of the first metal part 121.

[0611] In some examples, the second metal part 122 has an equal thickness structure or a substantially equal thickness structure, and the first metal part 121 can have a non-equal thickness structure. In the direction of the first metal part 121 pointing to the second metal part 122, the thickness of the first metal part 121 is arranged in an increasing manner, which can be in a stepped increasing manner or a slow increasing manner. The thickness of the part of the first metal part 121 away from the transition part 1221 is less than the thickness of the second metal part 122.

[0612] By adopting the technical scheme of the embodiment, the thickness of the second metal part 122 can be greater than the thickness of the first metal part 121 at least in part. The thickness of the second metal part 122 is large, the overcurrent capability of the second metal part 122 is improved, the heat generation of the second metal part 122 is reduced, the melting risk of the first insulating part 41 is reduced, the use reliability of the battery monomer 100 is improved, in addition, the overcurrent capability of the second metal part 122 is also improved, which is also conducive to improving the fast charging performance of the battery monomer 100.

[0613] In some embodiments, referring to FIG. 7, the first metal part 121 includes a first sub-part 1211 and a second sub-part 1212. The first sub-part 1211 is connected between the second sub-part 1212 and the second metal part 122. The first sub-part 1211 and the second sub-part 1212 are covered with the active material layer 20. The thickness of the first sub-part 1211 is greater than that of the second sub-part 1212. The thickness of the second metal part 122 is greater than or equal to the thickness of the first sub-part 1211.

[0614] The first metal part 121 can be a non-uniform thickness structure. In a direction of the first metal part 121 pointing to the second metal part 122, the first metal part 121 is divided into two parts. A part close to the second metal part 122 is a first sub-part 1211, and a part away from the second metal part 122 is a second sub-part 1212. Both the first sub-part 1211 and the second sub-part 1212 are covered with the active material layer 20.

[0615] In some examples, the first sub-part 1211 can be a uniform thickness structure, and the second sub-part 1212 can be a uniform thickness structure. The thickness of the first sub-part 1211 is greater than the thickness of the second sub-part 1212, and the thickness of the second metal part 122 is greater than or equal to the thickness of the first sub-part 1211. The thickness of the first sub-part 1211 is t3, the thickness of the second sub-part 1212 is t4, t3>t4, t2≥t3, and t1=t4. The first sub-part 1211 and the second sub-part 1212 form a stepped structure. The thickness of the second metal part 122 can be equal to the thickness of the first sub-part 1211, so that the second metal part 122 and the first sub-part 1211 form a uniform thickness structure. Alternatively, the thickness of the second metal part 122 can be greater than the thickness of the second sub-part 1212, so that the first sub-part 1211 and the second metal part 122 form a stepped structure.

[0616] In some examples, the first sub-part 1211 can also be a multi-segment structure. In a direction of the first metal part 121 pointing to the second metal part 122, the thickness of each segment gradually increases. For example, the first sub-part 1211 includes a first segment and a second segment. The first segment is located between the second segment and the second sub-part 1212. In a direction of the first metal part 121 pointing to the second metal part 122, the thickness of the first segment gradually increases. The second segment is a uniform thickness structure. The thickness of the second segment is equal to the thickness of the second metal part 122, that is, t3 can be equal to the thickness of the second segment. The thickness of the first segment gradually increases from the thickness of the second sub-part 1212 to the thickness of the second segment. In this way, the first segment can smoothly connect the second segment and the second sub-part 1212, which is beneficial to reduce stress concentration and improve structural strength. The thickness of the first segment can be equal to the thickness of the second metal part 122. The thickness of the second metal part 122 can also be greater than the thickness of the first segment.

[0617] In the use of the battery cell 100, in a direction of the first metal part 121 pointing to the second metal part 122, the electrons generated by the active material layer 20 gradually converge on the second metal part 122 through the first metal part 121. The number of electrons flowing through the first sub-part 1211 is greater than the number of electrons flowing through the second sub-part 1212. Therefore, the flow capacity of the first sub-part 1211 needs to be greater than the flow capacity of the second sub-part 1212.

[0618] The thickness of the first sub-portion 1211 is greater than the thickness of the second sub-portion 1212, so that the overcurrent capacity of the first sub-portion 1211 is greater than the overcurrent capacity of the second sub-portion 1212, which can reduce the current limitation, improve the overcurrent capacity of the first tab 1, reduce the heat generation of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0619] In some embodiments, referring to FIG. 7, the current collector 10 further comprises a conductive protective layer 13, the conductive protective layer 13 comprises a first protective portion 131 and a second protective portion 132, the first protective portion 131 is located between the first sub-portion 1211 and the active material layer 20, and the second protective portion 132 is located between the second sub-portion 1212 and the active material layer 20; wherein the thickness of the first protective portion 131 is less than the thickness of the second protective portion 132.

[0620] In some examples, along the first direction, the part of the conductive protective layer 13 between the first sub-portion 1211 and the active material layer 20 can be the first protective portion 131, and the part of the conductive protective layer 13 between the second sub-portion 1212 and the active material layer 20 can be the second protective portion 132, wherein the thickness of the first protective portion 131 is t5, the thickness of the second protective portion 132 is t6, and t5 < t6, which can reduce the thickness difference of the current collector 10 at the first protective portion 131 and the second protective portion 132.

[0621] In some examples, the first protective portion 131 can be an equal-thickness structure or an unequal-thickness structure, and t5 can be the maximum thickness of the first protective portion 131; the second protective portion 132 can be an equal-thickness structure or an unequal-thickness structure, and t6 can be the minimum thickness of the second protective portion 132.

[0622] For example, the first protective portion 131 comprises a first part and a second part, the first part is located between the first segment and the active material layer 20, and the second part is located between the second segment and the active material layer 20; the second protective portion 132 is located between the second sub-portion 1212 and the active material layer 20; along the direction of the first metal portion 121 pointing to the second metal portion 122, the thickness of the first part gradually decreases, and the second part is generally an equal-thickness structure, so that the thickness of the first protective portion 131 can be adapted to the thickness of the first sub-portion 1211, and the surface of the conductive protective layer 13 away from the insulating substrate 11 is close to a plane. Wherein t5 is equal to the thickness of the second part.

[0623] By adopting the technical scheme of the embodiment, the surface of the conductive protective layer 13 away from the insulating substrate 11 is close to a plane, which can reduce the roll damage and improve the overcurrent capacity of the metal layer 12; in addition, the winding bulging problem of the current collector 10 can also be reduced.

[0624] In some embodiments, referring to FIG. 7, the conductive protective layer 13 further comprises a third protective portion 133, the third protective portion 133 covers the surface of the second metal portion 122 away from the insulating substrate 11, and the thickness of the third protective portion 133 is less than or equal to the thickness of the first protective portion 131.

[0625] In some examples, along the first direction, the conductive protective layer 13 can be divided into three portions, a portion close to the conductive member 30 is the third protective portion 133, a portion away from the conductive member 30 is the second protective portion 132, and a portion in the middle is the first protective portion 131, wherein the thickness of the third protective portion 133 is t7, t7≤t5<t6; in addition, the thickness of the second metal portion 122 is greater than or equal to the thickness of the first sub-portion 1211, which can reduce the thickness difference of the current collector 10 at the first protective portion 131 and the third protective portion 133, and is conducive to the surface of the conductive protective layer 13 away from the metal layer 12 being close to a plane. The third protective portion 133 can cover the transition portion 1221.

[0626] For example, the second protective portion 132, the third protective portion 133, the second metal portion 122, and the second sub-portion 1212 are all equal-thickness structures, and the first sub-portion 1211 and the first protective portion 131 are both unequal-thickness structures; the thickness of the first sub-portion 1211 and the thickness of the first protective portion 131 are matched to make the surface of the conductive protective layer 13 away from the insulating substrate 11 close to a plane.

[0627] By adopting the technical scheme of this embodiment, the third protective portion 133 is provided, which can make the conductive protective layer 13 protrude from the active material layer 20, so that the active material layer 20 and the metal layer 12 can be better separated, in addition, the thickness of the third protective portion 133 is not too large, which is conducive to reducing the waste of materials and saving the manufacturing cost of the battery monomer 100.

[0628] The battery monomer 100 of the present application will be described below in combination with some embodiments.

[0629] Embodiment One

[0630] Referring to FIGS. 3-11 and 18, in this embodiment, the battery monomer 100 comprises a cover 201, a shell 202, and an electrode assembly 101, the electrode assembly 101 is installed in the shell 202, the cover 201 covers the opening of the shell 202 to seal the shell 202, and the cover 201 is provided with an electrode lead-out portion 2011.

[0631] In this embodiment, the electrode assembly 101 comprises a first electrode sheet 1, a second electrode sheet 2, and a separator 3, the separator 3 is located between the first electrode sheet 1 and the second electrode sheet 2, and the polarities of the first electrode sheet 1 and the second electrode sheet 2 are opposite, wherein the first electrode sheet 1 can be a positive electrode sheet, and the second electrode sheet 2 is a negative electrode sheet.

[0632] In the embodiment, the first tab 1 includes the current collector 10, the active material layer 20 and the conductive member 30, the current collector 10 includes the insulating base body 11, the metal layer 12 and the conductive protective layer 13, the insulating base body 11 is covered with the metal layer 12 on opposite surfaces in the thickness direction, the surface of the metal layer 12 away from the insulating base body 11 is covered with the conductive protective layer 13, and the surface of the conductive protective layer 13 away from the insulating base body 11 is covered with the active material layer 20.

[0633] In the embodiment, the metal layer 12 includes the first metal part 121 and the second metal part 122, the second metal part 122 includes the transition part 1221 and at least one protruding part 1222, the protruding part 1222, the transition part 1221 and the first metal part 121 are arranged in the first direction, the transition part 1221 is connected between the first metal part 121 and the protruding part 1222, the active material layer 20 covers the first metal part 121, the protruding part 1222 and the transition part 1221 are not covered with the active material layer 20, and the first direction is perpendicular to the thickness direction of the current collector 10.

[0634] In the embodiment, the two metal layers 12 are welded with the conductive member 30, the conductive member 30 includes the first connecting part 31 and the second connecting part 32 connected with each other, the first connecting part 31 is welded with the second metal part 122 to form the first welding mark 51, and the second connecting parts 32 of the two conductive members 30 are welded to form the second welding mark 52.

[0635] In the embodiment, the first welding mark 51 includes the first welding mark part 511, the protruding part 1222 includes the first protruding sub-part 12221 and the second protruding sub-part 12222, the first protruding sub-part 12221 is connected between the second protruding sub-part 12222 and the transition part 1221, the size of the second protruding sub-part 12222 in the second direction is smaller than the size of the first protruding sub-part 12221 in the second direction, the first protruding sub-part 12221 is welded with the first connecting part 31 to form the first welding sub-part 5111, the second protruding sub-part 12222 is welded with the first connecting part 31 to form the second welding sub-part 5112, and the first welding sub-part 5111 and the second welding sub-part 5112 form the first welding mark part 511. The second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0636] In the embodiment, the number of the protruding parts 1222 is multiple, and the multiple protruding parts 1222 are arranged at intervals in the second direction, and the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0637] In the embodiment, the electrode assembly 101 includes the first insulating part 41, and the first insulating part 41 covers the first welding mark 51 and the second welding mark 52.

[0638] In the embodiment, the first insulating member 41 comprises a plurality of first insulating portions 4121, one side of the first insulating portions 4121 covers the second solder print 52 along the first direction, the other side of the first insulating portions 4121 covers the transition portion 1221, the plurality of first insulating portions 4121 are sequentially connected to form an entirety along the second direction, the first insulating portions 4121 correspondingly cover the protruding portions 1222, the portions corresponding to the regions of the transition portion 1221 without the protruding portions 1222 between two adjacent first insulating portions 4121 form blocking portions 4131; the blocking portions 4131 of the two first insulating members 41 are in abutment.

[0639] In the embodiment, the electrode assembly 101 further comprises a second insulating member 42, the second insulating member 42 covers the surface of the second metal portion 122 away from the insulating substrate 11, the second insulating member 42 is located between the first connecting portion 31 and the active material layer 20, and the first insulating member 41 covers the second insulating member 42. The second insulating member 42 is a first phase change heat storage layer.

[0640] Embodiment Two

[0641] The difference between this embodiment and Embodiment One is that, as shown in FIGS. 12-16, the first solder print 51 comprises a first solder print portion 511 and a second solder print portion 512, the first connecting portion 31 further comprises a second connecting sub-portion 312, the first connecting sub-portion 311 is connected to the second connecting portion 32 and the second connecting sub-portion 312, the first connecting sub-portion 311 is soldered to the protruding portion 1222 to form the first solder print portion 511, and the second connecting sub-portion 312 is soldered to the transition portion 1221 to form the second solder print portion 512.

[0642] In the embodiment, the first insulating member 41 further comprises a second insulating portion 4122, the second insulating portion 4122 is connected to the first insulating portion 4121 and covers the second solder print portion 512.

[0643] Embodiment Three

[0644] The difference between this embodiment and Embodiment One is that, as shown in FIG. 17, the electrode assembly 101 does not comprise the second insulating member 42, one side of the first insulating member 41 covers the first solder print 51, and the other side of the first insulating member 41 covers the active material layer 20.

[0645] Embodiment Four

[0646] The difference between this embodiment and Embodiment One is that, as shown in FIGS. 19 and 20, the first insulating member 41 comprises a first insulating substrate 11 and a first adhesive layer 4112, the first adhesive layer 4112 is bonded between the first solder print 51 and the first insulating substrate 11.

[0647] Embodiment Five

[0648] The embodiment is different from the embodiment four in that, referring to Figure 21, the first insulating member 41 comprises a second phase change heat storage layer 4113, which is located between the first adhesive layer 4112 and the second insulating base layer, and the adhesive layer is bonded between the first solder print 51 and the second phase change heat storage layer 4113.

[0649] In some embodiments, referring to Figure 2, a battery device 1100 is provided, comprising the battery cell 100 of the above embodiments.

[0650] The battery device 1100 of the embodiments of the present application adopts the battery cell 100 described above, and the battery cell 100 has good use reliability, and the battery device 1100 has good use reliability.

[0651] In some embodiments, referring to Figure 1, a power consumption device is provided, comprising the battery device 1100 of the above embodiments.

[0652] The power consumption device of the embodiments of the present application adopts the battery device 1100 described above, and the battery device 1100 has good use reliability, which is conducive to improving the use reliability of the power consumption device.

[0653] The above description of the various embodiments tends to emphasize the differences between the various embodiments, and the same or similar parts can be referred to each other, and for the sake of brevity, the details are not described herein.

[0654] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The application relates to a battery electrode assembly. The battery electrode assembly comprises: a housing provided with an electrode lead-out portion; an electrode assembly at least partially arranged in the housing, the electrode assembly comprising a first electrode tab, the first electrode tab comprising a current collector, a conductive member and an active material layer, the conductive member being electrically connected to the electrode lead-out portion; the current collector comprises an insulating base body and a metal layer, the insulating base body, the metal layer and the active material layer are arranged in a stacking manner along the thickness direction of the current collector, at least part of the metal layer is located between the insulating base body and the active material layer; the metal layer comprises a first metal portion and a second metal portion arranged in a connected manner along a first direction, the first direction being perpendicular to the thickness direction of the current collector; at least part of the first metal portion is covered with the active material layer, at least part of the second metal portion is not covered with the active material layer; the conductive member is welded to the surface of the second metal portion away from the insulating base body and forms a first welding mark; 2. The battery cell of claim 1, wherein: the electrode assembly comprises a first insulating member, the first insulating member covers at least part of the first welding mark.

3. The battery cell according to claim 1 or 2, characterized in that: In the direction of the first metal portion pointing to the second metal portion, the first insulating member protrudes from the edge of the first welding mark away from the active material layer; and / or, in the direction of the second metal portion pointing to the first metal portion, the first insulating member protrudes from the edge of the first welding mark close to the active material layer.

4. The battery cell of claim 3, wherein: The conductive member comprises a first connecting portion and at least one second connecting portion, the first connecting portion and the second connecting portion are connected, the second connecting portion is electrically connected to the electrode lead-out portion, and the first connecting portion is welded to the surface of the second metal portion away from the insulating base body and forms the first welding mark. The second metal portion comprises at least one protruding portion; In a second direction, the sum of the sizes of all the protruding portions is smaller than the size of the first metal portion, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector; 5. The battery cell of claim 4, wherein: The first connecting portion comprises at least one first connecting sub-portion, the first connecting sub-portion is connected to the second connecting portion, the first connecting sub-portion covers the surface of the protruding portion away from the insulating base body, and the first connecting sub-portion corresponds to the protruding portion in a one-to-one manner.

6. The battery cell of claim 5, wherein: The first insulating member comprises at least one first insulating portion, the first insulating portion covers the surface of the first connecting sub-portion away from the protruding portion, and the first connecting sub-portion corresponds to the first connecting sub-portion in a one-to-one manner. The first welding mark comprises at least one first welding mark portion, the first connecting sub-portion is welded to the surface of the protruding portion away from the insulating base body and forms the first welding mark portion; 7. The battery cell of claim 6, wherein: The first insulating portion covers at least part of the first welding mark portion. The protruding portion comprises a first protruding sub-portion and a second protruding sub-portion, the first protruding sub-portion is connected between the second protruding sub-portion and the first metal portion; in the second direction, the size of the first protruding sub-portion is greater than the size of the second protruding sub-portion; The first welding part includes a first welding sub-part, the first connecting part is welded to the first protruding sub-part and forms the first welding sub-part, and the first insulating part covers at least part of the first welding sub-part; And / or, the first welding part includes a second welding sub-part, the first connecting part is welded to the second protruding sub-part and forms the second welding sub-part, and the first insulating part covers at least part of the second welding sub-part.

8. The battery cell of claim 6 or 7, wherein: In a direction from the first metal part to the second metal part, the first insulating part protrudes from the first welding part away from the edge of the active material layer; and / or, in a direction from the second metal part to the first metal part, the first insulating part protrudes from the first welding part close to the edge of the active material layer.

9. The battery cell of any one of claims 6-8, wherein: In the second direction, opposite sides of the protruding part are flush with opposite sides of the corresponding first connecting sub-part, and opposite edges of the first welding part are flush with opposite sides of the corresponding first connecting sub-part.

10. The battery cell of any one of claims 5-9, wherein: In the second direction, at least one side of the opposite sides of the first insulating part protrudes from the side of the corresponding first connecting sub-part.

11. The battery cell of any one of claims 5-10, wherein: In a direction from the first metal part to the second metal part, the first insulating part protrudes from the corresponding first connecting sub-part away from the active material layer; and / or, in a direction from the second metal part to the first metal part, the first insulating part protrudes from the corresponding first connecting sub-part close to the active material layer.

12. The battery cell of any one of claims 5-11, wherein: The number of protruding parts is multiple, the first connecting part includes multiple first connecting sub-parts, multiple protruding parts are arranged in the second direction, and multiple first connecting sub-parts are arranged in the second direction; the number of second connecting parts is multiple, multiple second connecting parts are arranged in the second direction, and the first connecting sub-part and the second connecting part are connected one by one.

13. The battery cell of claim 12, wherein: The adjacent two first insulating parts are arranged separately or connected.

14. The battery cell of any one of claims 2-13, wherein: The second metal part includes a transition part and at least one protruding part, the transition part is connected between the protruding part and the first metal part; In the second direction, the size of the transition part is greater than the sum of the sizes of all the protruding parts, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

15. The battery cell of claim 14, wherein: In the second direction, the size of the first metal part is L1, the size of the transition part is L2, and 0.8≤L2 / L1≤1.

16. The battery cell of claim 14 or 15, wherein: The first welding part includes a second welding sub-part, the first connecting part includes a second connecting sub-part connected with the second connecting part, the second connecting sub-part is welded to the transition part and forms the second welding sub-part.

17. The battery cell of claim 16, wherein: In the second direction, the size of the transition part is L2, the size of the second welding sub-part is L3, and 0.8≤L3 / L2≤1.

18. The battery cell of claim 16 or 17, wherein: The side of the transition part facing away from the first metal part, the edge of the second welding sub-part facing away from the active material layer, and the side of the second connecting sub-part facing away from the active material layer are flush.

19. The battery cell of any one of claims 16-18, wherein: The first insulating member includes a second insulating portion covering at least part of the second welding portion.

20. The battery cell of claim 19, wherein: In a direction from the first metal portion to the second metal portion, the second insulating portion protrudes from the second welding portion away from an edge of the active material layer; and / or, in a direction from the second metal portion to the first metal portion, the second insulating portion protrudes from the second welding portion close to an edge of the active material layer.

21. The battery cell of claim 19 or 20, wherein: In a direction from the first metal portion to the second metal portion, the second insulating portion protrudes from the second connecting sub-portion away from a side of the active material layer.

22. The battery cell of any one of claims 19-21, wherein: In the second direction, opposite sides of the transition portion are flush with opposite sides of the second connecting sub-portion, and opposite edges of the second welding portion are flush with opposite sides of the second connecting sub-portion.

23. The battery cell of any one of claims 19-22, wherein: In the second direction, at least one of opposite sides of the second insulating portion protrudes from a corresponding side of the second connecting sub-portion.

24. The battery cell of any one of claims 19-23, wherein: In a direction from the first metal portion to the second metal portion, the second insulating portion protrudes from a side of the second connecting sub-portion away from the active material layer; and / or, in a direction from the second metal portion to the first metal portion, the second insulating portion protrudes from a side of the second connecting sub-portion toward the active material layer.

25. The battery cell of any one of claims 19-24, wherein: The first connecting portion includes at least one first connecting sub-portion connected between the second connecting portion and the second connecting sub-portion, the first connecting sub-portion covering a surface of the protruding portion away from the insulating base, and the first connecting sub-portion corresponding to the protruding portion one by one; The first insulating member includes at least one first insulating portion connected with the second insulating portion, the first insulating portion covering a surface of the first connecting sub-portion away from the protruding portion, and the first insulating portion corresponding to the first connecting sub-portion one by one.

26. The battery cell of claim 25, wherein: The number of the protruding portions is plural, and the plural protruding portions are arranged at intervals in the second direction; the number of the first connecting sub-portions is plural, and the plural first connecting sub-portions are arranged at intervals in the second direction; the number of the second connecting portions is plural, and the plural second connecting portions are arranged at intervals in the second direction; the first connecting sub-portion and the second connecting portion correspond to each other one by one, and the plural first connecting sub-portions are connected to a side of the second connecting sub-portion away from the active material layer; and the second connecting sub-portion is arranged continuously in the second direction.

27. The battery cell of any one of claims 16-26, wherein: The electrode assembly further includes a second tab opposite in polarity to the first tab, the second tab including a main functional portion arranged in the first direction and a tab portion, the main functional portion having a first end face at an end portion close to the second metal portion, and the tab portion extending outwardly from the first end face; In a direction from the first metal portion to the second metal portion, a side of the second connecting sub-portion away from the active material layer does not protrude the first end face; Or, in a thickness direction of the current collector, a projection of the first end face is located within a projection of the second connecting sub-portion.

28. The battery cell of any one of claims 2-27, wherein: The first insulating member protrudes from a side of the first connecting portion away from the active material layer in a direction in which the first metal portion points to the second metal portion; and / or, the first insulating member protrudes from a side of the first connecting portion close to the active material layer in a direction in which the second metal portion points to the first metal portion.

29. The battery cell of any one of claims 2-28, wherein: The first welding mark is spaced apart from the active material layer in the first direction.

30. The battery cell of claim 29, wherein: The electrode assembly further comprises a second insulating member covering a surface of the second metal portion away from the insulating substrate, the second insulating member being located between the first welding mark and the active material layer.

31. The battery cell of claim 30, wherein: The first connecting portion is spaced apart from the active material layer in the first direction.

32. The battery cell of claim 31, wherein: At least part of the second insulating member is located between the first connecting portion and the active material layer.

33. The battery cell of claim 32, wherein: The electrode assembly further comprises a second tab opposite to the first tab in polarity, the second tab comprising a main functional portion arranged in the first direction and a tab portion, the main functional portion having a first end face at an end portion close to the second metal portion, the tab portion extending outwardly from the first end face; In a thickness direction of the current collector, a projection of the first end face is located within a projection of the second insulating member.

34. The battery cell of any one of claims 30-33, wherein: In the first direction, one side of the first insulating member covers the first welding mark, and the other side of the first insulating member covers at least part of the second insulating member.

35. The battery cell of any one of claims 30-34, wherein: The second insulating member comprises a first phase change heat storage layer covering a surface of the second metal portion away from the insulating substrate.

36. The battery cell of claim 35, wherein: The material of the first phase change heat storage layer comprises at least one of an organic heat storage material and an inorganic heat storage material.

37. The battery cell of claim 35 or 36, wherein: The material of the first phase change heat storage layer comprises an organic heat storage material, and the organic heat storage material comprises at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

38. The battery cell of any one of claims 35-37, wherein: The material of the first phase change heat storage layer comprises an inorganic heat storage material, and the inorganic heat storage material comprises at least one of a nitrate, a carbonate, a fluoride, and a hydrochloride.

39. The battery cell of any one of claims 2-38, wherein: In the first direction, one side of the first insulating member covers the first welding mark, and the other side of the first insulating member covers the active material layer.

40. The battery cell of any one of claims 2-39, wherein: The number of the metal layers is two, the two metal layers cover opposite sides of the insulating substrate in a thickness direction of the current collector, and the number of the active material layers is two, the two active material layers cover the first metal portions of the two metal layers respectively; The number of the conductive members is two, the first connecting portions of the two conductive members are welded to the second metal portions of the two metal layers respectively and form the two first welding marks; The number of the first insulating members is two, and the two first insulating members cover the two first welding marks respectively.

41. The battery cell of claim 40, wherein: In a direction in which the first metal portion points to the second metal portion, the first insulating member protrudes from a part of the metal layer to form a blocking portion, and in a second direction, the blocking portion is located at a side portion of the second connecting portion, wherein the second direction is perpendicular to the first direction and a thickness direction of the current collector.

42. The battery cell of claim 41, wherein: The blocking portions of the two first insulating members are in abutment.

43. The battery cell of any one of claims 40-42, wherein: The second connecting portions of the two conductive members are welded and form a second welding mark.

44. The battery cell of claim 43, wherein: The first insulating member covers at least part of the second welding mark.

45. The battery cell of claim 44, wherein: In a direction from the first metal portion to the second metal portion, the first insulating member protrudes from an edge of the second welding mark away from the active material layer.

46. The battery cell of any one of claims 1-45, wherein: The electrode assembly further includes a second tab opposite to the first tab in polarity, the second tab includes a main body functional portion arranged in the first direction and a tab portion, the main body functional portion has a first end face at an end portion close to the second metal portion, and the tab portion extends outward from the first end face; in a thickness direction of the current collector, a projection of the first end face is located within a projection of the first insulating member.

47. The battery cell of any one of claims 1-46, wherein: The glass transition temperature of the first insulating member is greater than or equal to 150°C, and optionally, the glass transition temperature of the first insulating member is greater than or equal to 200°C.

48. The battery cell of any one of claims 1-47, wherein: The specific heat capacity of the first insulating member is greater than or equal to 1.2 J / g·℃.

49. The battery cell of any one of claims 1-48, wherein: The first insulating member includes a first insulating base layer and a first adhesive layer, and the first adhesive layer is bonded between the first welding mark and the first insulating base layer.

50. The battery cell of claim 49, wherein: The first insulating member further includes a second phase change heat storage layer, and the second phase change heat storage layer is connected between the first insulating base layer and the first adhesive layer, and the first adhesive layer is bonded between the second phase change heat storage layer and the first welding mark.

51. The battery cell of claim 50, wherein: The material of the second phase change heat storage layer includes at least one of an organic heat storage material and an inorganic heat storage material.

52. The battery cell of either claim 50 or 51, wherein: The material of the second phase change heat storage layer includes an organic heat storage material, and the organic heat storage material includes at least one of a fatty acid, a paraffin, a straight-chain alkane, a fatty alcohol, and an ester substance.

53. The battery cell of any one of claims 50-52, wherein: The material of the second phase change heat storage layer includes an inorganic heat storage material, and the inorganic heat storage material includes at least one of a nitrate, a carbonate, a fluoride, and a hydrochloride.

54. The battery cell of any one of claims 50-53, wherein: The layer thickness of the second phase change heat storage layer ranges from 1 μm to 5 μm.

55. The battery cell of any one of claims 50-54, wherein: The glass transition temperature of the first adhesive layer is greater than the phase transition temperature of the second phase change heat storage layer, and / or the glass transition temperature of the first insulating base layer is greater than the phase transition temperature of the second phase change heat storage layer.

56. The battery cell of any one of claims 50-55, wherein: The material of the first insulating base layer includes at least one of polypropylene, polyethylene terephthalate, aramid 1313, polyvinylidene fluoride, and cellulose.

57. The battery cell of any one of claims 50-56, wherein: The material of the first adhesive layer includes at least one of acrylic acid, ethylene acrylic acid copolymer, rubber, and latex.

58. The battery cell of any one of claims 50-57, wherein: The layer thickness of the first adhesive layer ranges from 1 μm to 7 μm.

59. The battery cell of any one of claims 50-58, wherein: The layer thickness of the first insulating base layer ranges from 1 μm to 10 μm.

60. The battery cell of any one of claims 1-59, wherein: The current collector further includes a conductive protective layer, and at least part of the conductive protective layer is located between the active material layer and the first metal portion.

61. The battery cell of claim 60, wherein: In a direction from the first metal portion to the second metal portion, the conductive protective layer protrudes from an end portion of the active material layer close to the second metal portion.

62. The battery cell of any one of claims 1-61, wherein: The thickness of at least part of the first metal portion is less than the thickness of the second metal portion.

63. The battery cell of claim 62, wherein: The first metal portion includes a first sub-portion and a second sub-portion, the first sub-portion is connected between the second sub-portion and the second metal portion, the first sub-portion and the second sub-portion are covered with the active material layer, the thickness of the first sub-portion is greater than the thickness of the second sub-portion, and the thickness of the second metal portion is greater than or equal to the thickness of the first sub-portion.

64. The battery cell of claim 63, wherein: The current collector further includes a conductive protective layer, the conductive protective layer includes a first protective portion and a second protective portion, the first protective portion is located between the first sub-portion and the active material layer, and the second protective portion is located between the second sub-portion and the active material layer; wherein the thickness of the first protective portion is less than the thickness of the second protective portion.

65. The battery cell of claim 64, wherein: The conductive protective layer further includes a third protective portion, the third protective portion covers a surface of the second metal portion away from the insulating base body, and the thickness of the third protective portion is less than or equal to the thickness of the first protective portion.

66. A battery device, comprising: The battery cell includes any one of claims 1-65.

67. An electrical device, comprising: The battery device includes claim 66.

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