Battery cell, battery device, and electrical device

Abstract

A battery cell (100), a battery device (1100), and an electrical device. The battery cell (100) comprises 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 accommodated in the housing (200). The electrode assembly (101) comprises a first electrode plate (1) and a first insulating member (41). The first electrode plate (1) comprises a conductive member (30), a current collector (10), and an active material layer (20). 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 a thickness direction of the current collector (10). 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 main body portion (121). The main body portion (121) comprises a transition portion (1212) and a conductive portion (1211) arranged in a first direction and connected to each other, the first direction being perpendicular to the thickness direction of the current collector (10). At least part of the conductive portion (1211) is covered with the active material layer (20), while the transition portion (1212) is not covered with the active material layer (20). The conductive member (30) comprises a first connection portion (31) and at least one second connection portion (32) connected to each other. The first connection portion (31) is connected to the metal layer (12). The second connection portion (32) is electrically connected to the electrode lead-out portion (2011). The first connection portion (31) comprises a first connection sub-portion (311). The first connection sub-portion (311) covers a surface of the transition portion (1212) facing away from the insulating substrate (11). In a direction from the conductive portion (1211) toward the transition portion (1212), the first insulating member (41) protrudes from an edge of the first connection sub-portion (311) away from the active material layer (20).

Description

Battery cell, battery device and electric device

[0001] The present application claims priority from the international patent application PCT / CN2024 / 106988 entitled "Battery cell, battery device and electric device" filed on July 23, 2024, the whole content of the above application is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the technical field of battery, 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] The battery device includes one or more battery cells to meet different capacity usage requirements; but in the technology of battery cells, how to improve the use 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] CONTENT OF THE APPLICATION

[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 use reliability of the battery cell.

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

[0009] In some embodiments of the first aspect, the battery cell comprises a housing and an electrode assembly, the housing is provided with an electrode lead-out portion; at least part of the electrode assembly is accommodated in the housing, the electrode assembly comprises a first electrode tab and a first insulating member, the first electrode tab comprises a conductive member, a current collector and an active material layer, 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 stacked in 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 main body portion, the main body portion comprises a transition portion and a conductive portion arranged and connected in a first direction, the first direction is perpendicular to the thickness direction of the current collector; at least part of the conductive portion is covered with the active material layer, the transition portion is not covered with the active material layer; the conductive member comprises a first connecting portion and at least one second connecting portion connected to each other, the first connecting portion is connected to the metal layer, the second connecting portion is electrically connected to the electrode lead-out portion, the first connecting portion comprises a first connecting sub-portion, the first connecting sub-portion covers a surface of the transition portion away from the insulating base body; in the direction of the conductive portion pointing to the transition portion, the first insulating member protrudes from an edge of the first connecting sub-portion away from the active material layer.

[0010] By adopting the technical scheme of the embodiment, the first insulating member can block burrs, metal debris and other components at the edge of the first connecting sub-portion away from the active material layer, reduce the short circuit risk of the battery cell, and improve the use reliability of the battery cell; in addition, the current collector adopts the composite structure of the insulating base body and the metal layer, the thickness of the metal layer is small compared with the pure metal current collector, the burrs generated in the manufacturing process of the current collector are small, the internal short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

[0011] In some embodiments, in the direction of the transition portion pointing to the conductive portion, the first insulating member protrudes from an edge of the first connecting sub-portion close to the active material layer.

[0012] By adopting the technical scheme of the embodiment, the first insulating member can cover the edge of the first connecting sub-portion close to the active material layer, thereby blocking burrs, metal debris and other components at the edge of the first connecting sub-portion close to the active material layer, reducing the short circuit risk of the battery cell, and improving the use reliability of the battery cell; in addition, the first insulating member can cover the entire first connecting sub-portion, realize the overall insulation of the first connecting sub-portion, effectively reduce the short circuit of the battery cell, and improve the use reliability of the battery cell.

[0013] In some embodiments, in the first direction, the edge of the transition portion away from the conductive portion is flush with the edge of the first connecting sub-portion away from the active material layer.

[0014] By adopting the technical scheme of the embodiment, along the first direction, the edge of the transition portion away from the conductive portion is flush with the edge of the first connecting sub-portion away from the active material layer, the structure of the first pole piece is regular, the manufacturing and processing are facilitated, the redundancy of the first connecting sub-portion or the transition portion can be reduced, the space is saved, and the energy density of the battery monomer is improved; in addition, the first insulating piece also protrudes from the edge of the transition portion away from the active material layer, blocks burrs, metal scraps and other components at the edge of the transition portion away from the active material layer, reduces the short circuit risk of the battery monomer, and improves the use reliability of the battery monomer.

[0015] In some embodiments, along the second direction, the size of the conductive portion is L1, the size of the transition portion is L2, and 0.8≤L2 / L1≤1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0016] 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 improve the connection area between the first connecting sub-portion and the transition portion, improve the current-carrying capacity between the first connecting sub-portion and the transition portion, improve the current-carrying capacity of the first pole piece, reduce the heat generation of the battery monomer, and improve the fast charging performance of the battery monomer.

[0017] In some embodiments, the first connecting portion is welded to the surface of the metal layer away from the insulating base to form a first welding mark, and along the first direction, the first welding mark is located on the side of the active material layer close to the transition portion.

[0018] By adopting the technical scheme of the embodiment, the first connecting portion is welded to the metal layer, the welding operation is simple, and the manufacturing and processing of the first pole piece are facilitated; the first welding mark is located on the side of the active material layer close to the transition portion, so that the first welding mark is spaced from the active material layer, the risk of false welding of the first connecting portion and the metal layer caused by the active material layer is reduced, and the use reliability of the battery monomer is improved.

[0019] In some embodiments, the first insulating piece covers at least part of the first welding mark.

[0020] By adopting the technical scheme of the embodiment, the first insulating piece can block burrs, metal scraps and other components on the first welding mark, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0021] In some embodiments, the first welding mark includes a first welding mark portion, and the first connecting sub-portion is welded to the surface of the transition portion away from the insulating base to form the first welding mark portion.

[0022] By adopting the technical scheme of the embodiment, the first connecting sub-portion and the transition portion are welded, so that the current can directly flow to the conductive member through the transition portion, which is beneficial to improve the current-carrying capacity of the first pole piece and improve the fast charging performance of the battery monomer.

[0023] In some embodiments, along the second direction, the size of the transition portion is L2, the size of the first welding portion is L3, and 0.8≤L3 / L2≤1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0024] By adopting the technical scheme of this embodiment, the design of 0.8≤L3 / L2≤1 makes the size of the first welding portion along the second direction larger, which is beneficial to increase the connection area between the first connecting sub-portion and the transition portion, improve the flow capacity at the connection between the first connecting sub-portion and the transition portion, improve the flow capacity of the first tab, reduce the heat generation of the battery monomer, and improve the fast-charging performance of the battery monomer.

[0025] In some embodiments, the first insulating piece covers at least part of the first welding portion.

[0026] By adopting the technical scheme of this embodiment, the first insulating piece can block burrs, metal debris and other components on the first welding portion, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0027] In some embodiments, along the direction of the transition portion pointing to the conductive portion, the first insulating piece protrudes from the edge of the first welding portion close to the active material layer; and / or, along the direction of the conductive portion pointing to the transition portion, the first insulating piece protrudes from the edge of the first welding portion away from the active material layer.

[0028] By adopting the technical scheme of this embodiment, the first insulating piece can cover the edges of the first welding portion relatively distributed along the first direction, and block burrs, metal debris and other components at the edges of the first welding portion relatively distributed along the first direction, thereby effectively reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0029] In some embodiments, along the first direction, the edge of the first welding portion away from the active material layer is flush with the edge of the first connecting sub-portion away from the active material layer.

[0030] By adopting the technical scheme of this embodiment, along the first direction, the edge of the first welding portion away from the active material layer is flush with the edge of the first connecting sub-portion away from the active material layer, the structure of the first tab is regular, the processing and manufacturing of the first tab are facilitated, the redundancy of the first connecting sub-portion is reduced, the space is saved, and the energy density of the battery monomer is improved; in addition, the first insulating piece also protrudes from the edge of the first welding portion away from the active material layer, and the first insulating piece can cover the edge of the first welding portion away from the active material layer, thereby blocking the burrs at the edge of the first welding portion away from the active material layer, reducing the short circuit risk of the battery monomer, and improving the use reliability of the battery monomer.

[0031] In some embodiments, along the second direction, the opposite edges of the transition portion are flush with the opposite edges of the first connecting sub-portion, and the opposite edges of the first soldering portion are flush with the opposite edges of the first connecting sub-portion.

[0032] By adopting the technical scheme of this embodiment, the structure of the first pole piece at the two side surfaces oppositely distributed along the second direction is regular, which facilitates the processing and manufacturing of the first pole piece, reduces the redundancy of the first connecting sub-portion and the transition portion, saves space, and improves the energy density of the battery monomer. In addition, along the second direction, the size of the first soldering portion is equal to the size of the transition portion, which increases the soldering area between the transition portion and the first connecting sub-portion, and is beneficial to improving the overcurrent capacity of the first pole piece and the fast charging performance of the battery monomer.

[0033] In some embodiments, the metal layer further comprises at least one protruding portion, the transition portion is connected between the protruding portion and the conductive portion; along the second direction, the sum of the sizes of all the protruding portions is less than the size of the transition portion, the second direction is perpendicular to the first direction and the thickness direction of the current collector; the first connecting portion comprises at least one second connecting sub-portion, the second connecting sub-portion is connected between the first connecting sub-portion and the second connecting portion, the second connecting sub-portion covers the surface of the protruding portion away from the insulating base, and the second connecting sub-portion and the protruding portion correspond one-to-one.

[0034] By adopting the technical scheme of this embodiment, along the second direction, the size of the protruding portion is smaller than the size of the transition portion, which can remove the edge redundancy of the current collector, save space, and improve the energy density of the battery monomer. In addition, the protruding portion can also be connected with the second connecting sub-portion, thereby increasing the connection area between the metal layer and the first connecting portion, improving the overcurrent capacity between the metal layer and the first connecting portion, and improving the fast charging performance of the battery monomer.

[0035] In some embodiments, the first soldering portion comprises at least one second soldering portion, and the second connecting sub-portion is soldered with the corresponding protruding portion to form a second soldering portion.

[0036] By adopting the technical scheme of this embodiment, the second connecting sub-portion is soldered with the protruding portion, which can realize the connection between the first connecting portion and the metal layer.

[0037] In some embodiments, the first insulating piece covers at least part of the second soldering portion.

[0038] By adopting the technical scheme of this embodiment, the first insulating piece can block burrs, metal debris and other components on the second soldering portion, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0039] In some embodiments, the first insulating member protrudes the second solder part to be close to the edge of the active material layer in the direction from the transition part to the conductive part; and / or, the first insulating member protrudes the second solder part to be away from the edge of the active material layer in the direction from the conductive part to the transition part.

[0040] By adopting the technical scheme of this embodiment, the first insulating member can cover the edges of the second solder part that are relatively distributed in the first direction, and can block burrs, metal debris and other components at the edges of the second solder part that are relatively distributed in the first direction, thereby effectively reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0041] In some embodiments, the first insulating member protrudes the second connecting sub-part to be close to the edge of the active material layer in the direction from the transition part to the conductive part; and / or, the first insulating member protrudes the second connecting sub-part to be away from the edge of the active material layer in the direction from the conductive part to the transition part.

[0042] By adopting the technical scheme of this embodiment, the first insulating member can cover the edges of the second connecting sub-part that are relatively distributed in the first direction, and can block burrs, metal debris and other components at the edges of the second connecting sub-part that are relatively distributed in the first direction, thereby effectively reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0043] In some embodiments, the first insulating member includes a first insulating part and at least one second insulating part, the first insulating part covers the first connecting sub-part, and the second insulating part covers the second connecting sub-part, and the second insulating part corresponds to the second connecting sub-part one by one.

[0044] By adopting the technical scheme of this embodiment, the first insulating member can cover the first connecting sub-part and the second connecting sub-part, increase the coverage area of the first insulating member, improve the insulation effect of the first insulating member, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0045] In some embodiments, in the second direction, at least one side of the first insulating part protrudes from the corresponding side of the first connecting sub-part.

[0046] By adopting the technical scheme of this embodiment, the first insulating part can block burrs at the side of the first connecting sub-part in the second direction, thereby reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0047] In some embodiments, the number of protrusions is multiple, the number of second connecting sub-parts is multiple, the multiple protrusions are arranged at intervals along the second direction, the multiple second connecting sub-parts are arranged at intervals along the second direction, the multiple protrusions and the multiple second connecting sub-parts are arranged one-to-one, the number of second connecting parts is multiple, the multiple second connecting parts are arranged at intervals along the second direction, the second connecting sub-parts are connected one-to-one with the second connecting parts, and the multiple second connecting sub-parts are connected to the edge of the first connecting sub-part away from the active material layer; the first connecting sub-part is arranged continuously along the second direction; the number of second insulating parts is multiple, the multiple second insulating parts are arranged along the second direction, and the second insulating parts correspond one-to-one with the second connecting sub-parts.

[0048] By adopting the technical scheme of this embodiment, the first connecting sub-part is arranged continuously along the second direction, the multiple second connecting sub-parts can be connected as a whole, the first connecting sub-part can provide good support for the second connecting sub-part, the risk of the second connecting sub-part bending and being inserted between the first and second pole pieces can be reduced, the short circuit risk of the battery monomer can be reduced, and the use reliability of the battery monomer can be improved; along the second direction, the size of the first connecting sub-part is large, which is conducive to increasing the welding area between the first connecting sub-part and the transition part, increasing the overcurrent capacity between the first connecting part and the transition part, increasing the overcurrent capacity of the first pole piece, and improving the fast charging performance and use reliability of the battery monomer; the multiple protrusions are arranged at intervals along the second direction, which is conducive to dividing the main body part into multiple regions along the second direction, and one region can correspond to one protrusion, the electrons in each region can be transmitted to the electrode lead-out part through the corresponding protrusion, the regional transmission of the electrons of the main body part can be realized, the transmission path of the electrons in each region is short to the corresponding protrusion, which is conducive to reducing the transmission distance of the electrons, reducing the overall resistance of the first pole piece, and improving the fast charging performance and use reliability of the battery monomer.

[0049] In some embodiments, two adjacent second insulating parts are connected.

[0050] By adopting the technical scheme of this embodiment, the two adjacent second insulating parts can be directly connected to form a whole structure, and the installation of the first insulating part can be facilitated; at the same time, the second insulating part can also cover the opposite edges of the second connecting sub-part along the second direction, block the sharp protrusions, metal debris and other components at the opposite side surfaces of the second connecting sub-part along the second direction, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0051] In some embodiments, along the first direction, the first welding mark and the active material layer are arranged at intervals.

[0052] By adopting the technical scheme of the embodiment, the gap between the first welding mark and the active material layer makes the welding of the first connecting part and the metal layer not welded on the active material layer, reduces the risk of false welding of the first connecting part and the metal layer, and improves the use reliability of the battery monomer.

[0053] In some embodiments, along the first direction, the distance between the first welding mark and the active material layer is S1, where 0.3mm≤S1≤5mm, and optionally, 0.5mm≤S1≤2.8mm.

[0054] By adopting the technical scheme of the embodiment, the design of 0.3mm≤S1≤5mm makes the first welding mark not welded on the active material layer, reduces the risk of false welding of the first connecting part and the metal layer, is conducive to improving the connection reliability of the first connecting part and the metal layer, and improves the use reliability of the battery monomer. In addition, the distance between the active material layer and the first welding mark is reasonable. The active material layer is relatively close to the first welding mark. Under the condition that the size of the metal layer in the first direction is certain, the active material layer can cover a larger area, which is conducive to improving the energy density of the battery monomer.

[0055] In some embodiments, the electrode assembly includes a second insulating piece, the second insulating piece covers the surface of the metal layer away from the insulating base, and the entire second insulating piece is located between the first welding mark and the active material layer.

[0056] 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, which can realize the insulation of this part, is conducive to reducing the short circuit risk of the battery monomer, and improves the use reliability of the battery monomer.

[0057] In some embodiments, along the first direction, the first connecting sub-part is arranged to be spaced apart from the active material layer.

[0058] By adopting the technical scheme of the embodiment, the first connecting sub-part is not in contact with the active material layer, which can reduce the mutual influence between the two, and is conducive to improving the performance of the battery monomer.

[0059] In some embodiments, at least part of the second insulating piece is located between the first connecting sub-part and the active material layer.

[0060] By adopting the technical scheme of the embodiment, the second insulating piece covers the part of the transition part between the first connecting sub-part and the active material layer, and the second insulating piece can play a supporting role on this part, thereby reducing the risk of cracks in this part. In addition, the second insulating piece covers the part of the transition part between the first connecting sub-part and the active material layer, which can also realize the insulation of this part, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0061] In some embodiments, the electrode assembly further comprises a second tab opposite to the first tab in polarity, the second tab comprises a main functional part and a tab part arranged along the first direction, the main functional part has a first end face close to the end of the transition part, and the tab part extends outward from the first end face; along the thickness direction of the current collector, the projection of the first end face is located within the projection of the second insulating piece.

[0062] By adopting the technical scheme of this embodiment, the first end face is arranged opposite to the second insulating piece, the second insulating piece can block burrs at the first end face, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0063] In some embodiments, along the first direction, one side of the first insulating piece covers the first connecting sub-part, and the other side of the first insulating piece covers at least part of the second insulating piece.

[0064] By adopting the technical scheme of this embodiment, the first insulating piece and the second insulating piece can realize double-layer insulation, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0065] In some embodiments, along the first direction, one side of the first insulating piece covers the first connecting sub-part, and the other side of the first insulating piece covers at least part of the second insulating piece.

[0066] By adopting the technical scheme of this embodiment, the first insulating piece has a wide coverage area and good insulation effect, which is conducive to improving the use reliability of the battery monomer; the first insulating piece can cover the end of the active material layer close to the transition part, block burrs of the active material layer close to the transition part, reduce the short circuit risk of the battery monomer, and improve the use reliability of the battery monomer.

[0067] In some embodiments, along the first direction, the size of the part of the active material layer covered by the first insulating piece is H, where 0.2mm≤H≤1.0mm, and optionally, 0.3mm≤H≤0.8mm.

[0068] By adopting the technical scheme of this embodiment, along the first direction, the size of the part of the active material layer covered by the first insulating piece is reasonable, which can simultaneously take into account blocking burrs at the end of the active material layer close to the transition part and the energy density of the battery monomer.

[0069] In some embodiments, the electrode assembly further comprises a second tab opposite to the first tab in polarity, the second tab comprises a main functional part and a tab part arranged along the first direction, the main functional part has a first end face close to the end of the transition part, and the tab part extends outward from the first end face; along the direction of the conductive part towards the transition part, the side of the first 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 first connecting sub-part.

[0070] By adopting the technical scheme of this embodiment, the side of the first connecting sub away from the active material layer does not protrude the first end face, so that the first end face is arranged opposite the hollowed-out area of the conductive member, which can reduce the short circuit risk of the battery monomer and is conducive to improving the use reliability of the battery monomer. In the thickness direction of the current collector, the projection of the first end face is located within the projection of the first connecting sub, so that the edge of the first connecting sub away from the active material layer is not arranged opposite the main functional part, which can reduce the short circuit risk of the battery monomer and is conducive to improving the use reliability of the battery monomer.

[0071] 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 in the first direction and a tab part, the main functional part having a first end face near an end of the transition 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 first insulating piece.

[0072] By adopting the technical scheme of this embodiment, the first insulating piece 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.

[0073] In some embodiments, the number of metal layers is two, the two metal layers covering opposite sides of the insulating base in the thickness direction of the current collector, the number of active material layers is two, the two active material layers covering the conductive parts of the two metal layers respectively; the number of conductive members is two, the first connecting parts of the two conductive members being connected to the two metal layers respectively; the number of first insulating pieces is two, the two first insulating pieces covering the first connecting sub parts of the two conductive members respectively.

[0074] By adopting the technical scheme of this embodiment, the first connecting parts of the two conductive members are welded to the metal layers located on opposite sides of the insulating base, so that the second connecting 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 conductivity of the first tab, 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.

[0075] In some embodiments, in the direction of the conductive part pointing to the transition part, the part of the first insulating piece protruding from the first connecting sub forms a blocking part, and in the second direction, the blocking part is located at the side of the second connecting part, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

[0076] By adopting the technical scheme of this embodiment, the blocking part can block burrs, metal debris and other components at the edge of the first connecting sub away from the active material layer, reducing the short circuit risk of the battery monomer and improving the use reliability of the battery monomer.

[0077] In some embodiments, the blocking portions of the two first insulating pieces are in abutment.

[0078] By adopting the technical scheme of this embodiment, the blocking portions of the two first insulating pieces are in abutment, so that the first connecting sub-portions can be wrapped around the burrs, metal debris and other components at the edges of the active material layer, the burrs at the edges of the active material layer are blocked, the risk of falling of the metal debris is reduced, the risk of short circuit of the battery monomer is reduced, and the use reliability of the battery monomer is improved.

[0079] In some embodiments, the second connecting portions of the two conductive members are welded and form a second welding mark.

[0080] By adopting the technical scheme of this embodiment, the second connecting portions of the two conductive members are welded to electrically connect the metal layers on the 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, reducing the heat generation of the battery monomer, and improving the use reliability of the battery monomer.

[0081] In some embodiments, the first insulating piece covers at least part of the second welding mark.

[0082] By adopting the technical scheme of this embodiment, the first insulating piece can cover the second welding mark, block the sharp protrusions, metal debris and other components on the second welding mark, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0083] In some embodiments, in the direction of the conductive portion pointing to the transition portion, the first insulating piece protrudes from the edge of the second welding mark away from the active material layer.

[0084] By adopting the technical scheme of this embodiment, the first insulating piece can cover the entire second welding mark, block the burrs, metal debris and other components on the second welding mark, reduce the risk of short circuit of the battery monomer, and improve the use reliability of the battery monomer.

[0085] In some embodiments, the current collector comprises a conductive protective layer, and at least part of the conductive protective layer is located between the active material layer and the conductive portion.

[0086] By adopting the technical scheme of this embodiment, the conductive protective layer can separate the active material layer and the conductive portion, play a protective role on the conductive portion, reduce the risk of cracks of the conductive portion caused by rolling the active material layer, be conducive to improving the electronic transmission capacity of the conductive portion, and improve the fast charging performance of the battery monomer.

[0087] In some embodiments, in the direction of the conductive portion pointing to the transition portion, the conductive protective layer protrudes from the end of the active material layer close to the first connecting sub-portion.

[0088] 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 capability of the first tab is better, and the fast charging performance and use reliability of the battery monomer are improved.

[0089] In some embodiments, the protruding length of the conductive protective layer protruding from the active material layer ranges from 0.3 mm to 0.8 mm in the direction of the conductive part pointing to the transition part.

[0090] By adopting the technical scheme of the embodiment, the overcurrent capability and the energy density of the battery monomer can be better balanced.

[0091] In some embodiments, the first connecting part is welded to the surface of the metal layer away from the insulating base to form a first welding mark, and the conductive protective layer and the first welding mark are arranged at intervals in the first direction.

[0092] By adopting the technical scheme of the embodiment, the first connecting part will not be welded to the conductive protective layer, which can reduce the risk of false welding of the first connecting part and the metal layer, and improve the reliability of welding of the first connecting part and the metal layer.

[0093] In some embodiments, the first insulating piece is connected with the first tab.

[0094] By adopting the technical scheme of the embodiment, the first insulating piece is connected to the first tab, and the first insulating piece can be fixed, so as to stably block burrs, metal debris and other components away from the edge of the active material layer, thereby improving the use reliability of the battery monomer.

[0095] In some embodiments, the first insulating piece includes an insulating base layer and an adhesive layer, and the adhesive layer is bonded between the insulating base layer and the first tab.

[0096] By adopting the technical scheme of the embodiment, the first insulating piece adopts the structure of the adhesive tape, which can be directly pasted on the first tab to reduce the risk of missing coverage; the insulating base layer and the adhesive layer cover the first tab to block the burrs on the first tab, and the thickness of the insulating base layer and the thickness of the adhesive layer do not need to be set too large, thereby improving the energy density of the battery monomer; the insulating base layer has good structural strength and can stably block the burrs on the first tab, thereby improving the use reliability of the battery monomer; the adhesive layer can stably fix the insulating base layer on the first tab to reduce the risk of falling off of the first insulating piece; the metal debris on the first tab can also be bonded on the adhesive layer, which can effectively reduce the risk of falling of the metal debris on the first tab and reduce the short circuit risk of the battery monomer.

[0097] In some embodiments, the thickness of the insulating base layer ranges from 6 μm to 15 μm; and / or, the thickness of the adhesive layer ranges from 0.5 μm to 3 μm.

[0098] By adopting the technical solutions of the embodiment, the internal insulation and the energy density of the battery monomer can be considered at the same time.

[0099] In some embodiments, the size of the first insulating piece in the first direction is W, where 3mm≤W≤9mm, and optionally, 4.5mm≤W≤6.5mm.

[0100] By adopting the technical solutions of the embodiment, the insulation reliability and the energy density of the battery monomer can be considered at the same time.

[0101] In some embodiments, the thickness of the conductive part is less than the thickness of the transition part.

[0102] By adopting the technical solutions of the embodiment, the thickness of the transition part can be greater than the thickness of the conductive part at least in part, the thickness of the transition part is large, which improves the current-carrying capacity of the transition part, reduces the heat generation of the transition part, reduces the risk of melting of the first insulating piece, improves the use reliability of the battery monomer, in addition, also improves the current-carrying capacity of the transition part, which is also conducive to improving the fast-charging performance of the battery monomer.

[0103] In some embodiments, the conductive part includes a first sub-part and a second sub-part, the first sub-part is connected between the second sub-part and the transition part, the first sub-part and the second sub-part are covered with an active material layer, the thickness of the first sub-part is greater than the thickness of the second sub-part, and the thickness of the transition part is greater than or equal to the thickness of the first sub-part.

[0104] By adopting the technical solutions of the embodiment, the thickness of the first sub-part is greater than the thickness of the second sub-part, so that the current-carrying capacity of the first sub-part is greater than the current-carrying capacity of the second sub-part, which can reduce the limitation of the current, improve the current-carrying 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.

[0105] 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 sub-part and the active material layer, and the second protective part is located between the second sub-part and the active material layer; wherein the thickness of the first protective part is less than the thickness of the second protective part.

[0106] By adopting the technical solutions 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 current-carrying capacity of the metal layer; in addition, the winding bulging problem of the current collector can also be reduced.

[0107] In some embodiments, the conductive protective layer further includes a third protective part, the third protective part covers the surface of the transition 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.

[0108] 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.

[0109] In some embodiments, the metal layer further comprises at least one protruding part, the transition part is connected between the protruding part and the conductive part; along the second direction, the sum of the sizes of all the protruding parts is less than the size of the transition part, the second direction is perpendicular to the first direction and the thickness direction of the current collector; the thickness of the protruding part is greater than or equal to the thickness of the transition part.

[0110] By adopting the technical scheme of the embodiment, the thickness of the protruding part is large, which can improve the flow capacity of the protruding part, is beneficial to improve the flow capacity of the first pole piece, reduce the heating of the battery monomer, and is beneficial to improve the fast charging performance and use reliability of the battery monomer.

[0111] In the second aspect, in some embodiments, the battery device comprises the battery monomer of the above-mentioned embodiments.

[0112] The battery device of the embodiments of the present application adopts the above-mentioned battery monomer, and the use reliability of the battery monomer is good, and the use reliability of the battery device is good.

[0113] In the third aspect, in some embodiments, the electric device comprises the battery device of the above-mentioned embodiments.

[0114] The electric device of the embodiments of the present application adopts the above-mentioned battery device, and the use reliability of the battery device is good, which is beneficial to improve the use reliability of the electric device.

[0115] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0116] In order to more clearly illustrate the technical scheme in the embodiments of the present 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 present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0117] Fig. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0118] Fig. 2 is a structural schematic diagram of a battery device provided by some embodiments of the present application.

[0119] FIG. 3 is a structural schematic diagram of a battery cell according to some embodiments of the present application.

[0120] FIG. 4 is a structural schematic diagram of an electrode assembly according to some embodiments of the present application.

[0121] FIG. 5 is a sectional view along line A-A in FIG. 4.

[0122] FIG. 6 is a structural schematic diagram of a first electrode tab, a first insulating member, and a second insulating member according to some embodiments of the present application.

[0123] FIG. 7 is a sectional view along line B-B in FIG. 6.

[0124] FIG. 8 is a structural schematic diagram of a first electrode tab and a second insulating member according to some embodiments of the present application.

[0125] FIG. 9 is an enlarged view of a portion D in FIG. 8.

[0126] FIG. 10 is a structural schematic diagram of a first electrode tab with a conductive member hidden according to some embodiments of the present application.

[0127] FIG. 11 is an enlarged view of a portion E in FIG. 10.

[0128] FIG. 12 is a sectional view along line C-C in FIG. 6.

[0129] FIG. 13 is a sectional view along line B-B in FIG. 6 of a first electrode tab, a first insulating member, and a second insulating member according to some embodiments of the present application.

[0130] FIG. 14 is a structural schematic diagram of a first insulating member according to some embodiments of the present application.

[0131] FIG. 15 is a sectional view along line F-F in FIG. 14.

[0132] In the drawings, reference numerals:

[0133] 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, main body portion; 1211, conductive portion; 12111, first sub-portion; 12112, second sub-portion; 1212, transition portion; 122, protruding 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, insulating base layer; 4112, adhesive 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; 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, separator; 200, housing; 201, end cap; 2011, electrode lead-out portion; 202, case; 300, box; 301, first box portion; 302, second box portion. DETAILED DESCRIPTION

[0134] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application more clearly understood, the following will be further described in detail in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not intended to limit the present application.

[0135] 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 terms "include" and "have" and any variations thereof used in the specification and claims of this application and the above description of the drawings are intended to cover not exclusive inclusion.

[0136] 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.

[0137] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least some embodiments. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. As will be apparent to those of ordinary skill in the art, embodiments described herein can be combined with other embodiments in any way deemed useful.

[0138] In the description of the embodiments of the present application, the term“and / or” only means an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character“ / ” herein generally means that the front and rear associated objects are in an“or” relationship.

[0139] 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.

[0140] In the description of the embodiments of the present application, the technical terms“center”,“longitudinal”,“transverse”,“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.

[0141] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms“mounting”,“connecting”,“connecting”,“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 of ordinary skill 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.

[0142] In the description of the embodiments of the present application, unless specifically defined and limited otherwise, when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or indirectly on the other element with intervening elements present. 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 with intervening elements present.

[0143] 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, etc.

[0144] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, or a battery cell of other shapes, the prismatic battery cell including a square cell, a blade cell, a multi-prismatic battery cell, for example, a hexagonal prismatic battery cell, etc.

[0145] The battery device referred to in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0146] In some embodiments, the battery device can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0147] In some embodiments, the battery device can be a battery pack, and the battery pack includes a box body and battery cells, and the battery cells or battery modules are accommodated in the box body.

[0148] In some embodiments, the box body can be part of the chassis structure of the vehicle. For example, part of the box body can be at least part of the floor of the vehicle, or part of the box body can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0149] 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, etc.

[0150] The battery cell generally includes an electrode assembly and a case, and the electrode assembly is accommodated in the case. The electrode assembly includes a positive electrode and a negative electrode. During the charging and discharging of the battery cell, active ions (for example, lithium ions) are inserted and extracted between the positive electrode and the negative electrode.

[0151] In some embodiments, the electrode assembly further includes a separator, which is arranged 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.

[0152] The shell is used to encapsulate the electrode assembly and other components such as electrolyte. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0153] In some embodiments, the positive electrode can be a positive electrode sheet, which 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, which 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.

[0154] 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, pure metal foil material is prone to produce metal burrs, and the burrs can pierce the separator, causing internal short circuit and posing a great risk of fire and explosion of the battery cell.

[0155] 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, thereby reducing the risk of short circuit of the battery cell. The edge of the metal layer is usually connected with a conductive member, which includes a first connecting part and a second connecting part connected with each other, the first connecting part is connected with the metal layer, and the second connecting part is electrically connected with an electrode lead-out part, thereby realizing the input or output of the battery cell electric energy. However, during the use of the battery cell, the first connecting part includes a first connecting sub-part, which covers the edge of the main part of the metal layer. The edge of the first connecting sub-part away from the active material layer is prone to generate burrs during the manufacturing process, thereby increasing the risk of short circuit of the battery cell and being not conducive to improving the use reliability of the battery cell.

[0156] Based on this, the embodiments of the present application provide a technical scheme. The conductive member of the battery cell includes a first connecting part and at least one second connecting part connected with each other, the first connecting part includes a first connecting sub-part, which covers the transition part of the main part of the metal layer, the battery cell further includes a first insulating part, which covers the first connecting sub-part and protrudes from the edge of the first connecting sub-part away from the active material layer in the direction of the conductive part pointing to the transition part. The first insulating part can block the burrs at the edge of the first connecting sub-part away from the active material layer, thereby reducing the risk of short circuit of the battery cell and improving the use reliability of the battery cell.

[0157] The battery cell described in the embodiments of the present application is suitable for a battery device and a power utilization device using the battery device.

[0158] The battery device disclosed in the embodiments of the present application can be used in a power consumption device using the battery device as a power source or a variety of energy storage systems using the battery device as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0159] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0160] As shown in FIG. 1, the vehicle 1000 is internally 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 source of the vehicle 1000.

[0161] The vehicle 1000 can further include a controller 1200 and a motor 1300, the controller 1200 being used to control the battery device 1100 to supply power to the motor 1300, for example, for the working power consumption demand of the vehicle 1000 during starting, navigation, and driving.

[0162] In some embodiments of the present application, the battery device 1100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000. FIG. 2 is an exploded schematic view of the battery device 1100 provided in some embodiments of the present application. As shown in FIG. 2, the battery device 1100 includes a box body 300 and a battery cell, and the battery cell is contained in the box body 300.

[0163] The box body 300 is used to contain the battery cell, and the box body 300 can be of various structures. In some embodiments, the box body 300 can include a first box body part 301 and a second box body part 302, the first box body part 301 and the second box body part 302 are mutually covered, and the first box body part 301 and the second box body part 302 jointly define a containing space for containing the battery cell. The second box body part 302 can be a hollow structure with one end open, and the first box body part 301 is a plate-shaped structure, which is covered on the open side of the second box body part 302 to form the box body 300 with the containing space; or the first box body part 301 and the second box body part 302 can both be a hollow structure with one side open, and the open side of the first box body part 301 is covered on the open side of the second box body part 302 to form the box body 300 with the containing space. Of course, the first box body part 301 and the second box body part 302 can be of various shapes, such as a cylinder, a cuboid, and the like.

[0164] To improve the sealing performance of the first box part 301 and the second box part 302 after being connected, a sealing member such as sealing glue, sealing ring, etc. can be arranged between the first box part 301 and the second box part 302.

[0165] Suppose the first box part 301 is covered on the top of the second box part 302, the first box part 301 can also be called an upper box cover, and the second box part 302 can also be called a lower box 300.

[0166] In the battery device 1100, the battery cell can be one or multiple. If the battery cell is multiple, the multiple battery cells can be connected in series, in parallel, or in a mixed connection. The mixed connection means that there are both series connection and parallel connection among the multiple battery cells.

[0167] The multiple battery cells can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery cells is accommodated in the box 300. Of course, the multiple battery cells can be first connected in series, in parallel, or in a mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box 300.

[0168] Exemplarily, the battery cell can be the smallest unit constituting the battery device 1100.

[0169] As shown in FIG. 3, in some embodiments, the battery cell includes a housing 200 and an electrode assembly 101 accommodated in the housing 200. The electrode assembly 101 includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode and the negative electrode. Optionally, the electrode assembly 101 further includes a separator 3 arranged between the positive electrode and the negative electrode, which can reduce the risk of short circuit of the positive electrode and the negative electrode, and at the same time allow the active ions to pass through.

[0170] The housing 200 is used to encapsulate the electrode assembly 101 and other components such as electrolyte.

[0171] In some embodiments, the housing 200 includes a shell 202 and an end cover 201, and the shell 202 has an opening, and the end cover 201 is used to cover the opening.

[0172] The shell 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.

[0173] The shell 202 and the end cover 201 can be independent components. Exemplarily, an opening can be arranged on the shell 202, and the end cover 201 is used to cover the opening to form the internal cavity of the battery cell.

[0174] The shell 202 can be in various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the shell 202 can be determined according to the specific shape and size of the electrode assembly 101. The material of the shell 202 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, aluminum plastic film, steel plastic film, etc.

[0175] The shape of the end cover 201 can be adapted to the shape of the shell 202 to fit the shell 202. The material of the end cover 201 can be the same as or different from the material of the shell 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 monomer can have higher structural strength and reliable performance can also be improved.

[0176] The end cover 201 is connected to the shell 202 by welding, bonding, clamping or other means.

[0177] The shell 202 can be open at one end or both ends. In some examples, the shell 202 can be a one-side open structure, and the end cover 201 is provided as one and covers the shell 202. In other examples, the shell 202 can also be a two-side open structure, and the end cover 201 is provided as two, and the two end covers 201 cover the two openings of the shell 202, respectively.

[0178] In some embodiments, the battery monomer includes an electrode lead-out portion 2011. The number of electrode lead-out portions 2011 is two, and the two electrode lead-out portions 2011 are connected to the positive and negative electrode sheets, respectively, for outputting or inputting the electrical energy of the battery monomer.

[0179] In some embodiments, the battery monomer further includes an electrolyte contained in the shell 200. The electrolyte plays a role of conducting ions between the positive and negative electrodes. The electrolyte can be in a liquid state, a gel state or a solid state.

[0180] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0181] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonylimide, lithium bis-trifluoromethanesulfonylimide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoroboric oxalate, lithium boric oxalate, lithium difluorophosphoric oxalate, and lithium tetrafluorophosphoric oxalate.

[0182] In some embodiments, the solvent can include at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, butyl sulfone, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0183] The solvent can also be selected from ether solvents. 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.

[0184] In some embodiments, the gel-state electrolyte includes a polymer as a backbone network of the electrolyte, in combination with an ionic liquid-lithium salt.

[0185] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0186] 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.

[0187] 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 sulfide, argyrodite), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0188] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0189] Referring to FIGS. 4 and 5, the electrode assembly 101 according to an embodiment of the disclosure includes first and second polar plates 1 and 2 having opposite polarities.

[0190] 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.

[0191] 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.

[0192] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material layer is provided on either one or both of the two surfaces of the positive electrode current collector.

[0193] As an example, the positive electrode 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).

[0194] 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 only one kind alone, or two or more kinds in combination. Examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04(also can be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2(also can be referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2(also can be referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2(also can be referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2(also can be referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2(also can be referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15Al 0.05 O2) and modified compounds thereof, etc.

[0195] 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.

[0196] As an example, the negative electrode current collector can employ a metal foil, a foamed metal, or a composite current collector. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, etc. can be employed. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0197] As an example, the negative electrode active material layer includes a negative electrode active material. The negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. 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 electrode active material of the present application can also use other conventional materials that can be used as a negative electrode active material for the battery device 1100. These negative electrode active materials can be used alone only one or two or more can be used in combination.

[0198] In some embodiments, the material of the positive electrode current collector can be aluminum and the material of the negative electrode current collector can be copper.

[0199] In some embodiments, the electrode assembly 101 further includes a separator 3 for separating the first electrode tab 1 and the second electrode tab 2. The separator 3 can reduce the risk of positive and negative short circuits while allowing active ions to pass through.

[0200] 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.

[0201] 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. 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 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 surfaces of the positive and negative electrodes.

[0202] In some embodiments, the separator 3 is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrode sheets and functions to transport ions and separate the positive and negative electrodes.

[0203] In some embodiments, the electrode assembly 101 is a jelly-roll structure. As an example, the first electrode sheet 1 and the second electrode sheet 2 each have a belt shape, and the first electrode sheet 1, the separator 3, and the second electrode sheet 2 are wound to form the jelly-roll structure.

[0204] In some embodiments, the electrode assembly 101 is a stack structure.

[0205] As an example, a plurality of first electrode sheets 1 and a plurality of second electrode sheets 2 can be alternately stacked.

[0206] As an example, a plurality of first electrode sheets 1 can be provided, and the second electrode sheet 2 is folded to form a plurality of folded sections that are stacked.

[0207] As an example, the first electrode sheet 1 and the second electrode sheet 2 are each folded to form a plurality of folded sections that are stacked.

[0208] As an example, a plurality of separators 3 can be provided between any adjacent first electrode sheets 1 or second electrode sheets 2.

[0209] As an example, the separators 3 can be continuously provided between any adjacent first electrode sheets 1 or second electrode sheets 2 by being folded or wound.

[0210] In some embodiments, the electrode assembly 101 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0211] As shown in Figures 6-11, 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 a portion of the electrode assembly 101 is housed within the housing 200, and the electrode assembly 101 includes a first electrode 1 and a first insulating member 41. The first electrode 1 includes a conductive member 30, a current collector 10, and an active material layer 20. The current collector 10 includes 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 along the thickness direction of the current collector 10, and at least a portion of the metal layer 12 is located between the insulating substrate 11 and the active material layer 20; the metal layer 12 includes a main body portion 121, which includes components arranged and connected along a first direction. The transition portion 1212 and the conductive portion 1211 are perpendicular to the thickness direction of the current collector 10 in a first direction. At least a portion of the conductive portion 1211 is covered with the active material layer 20, while the transition portion 1212 is not covered with the active material layer 20. The conductive member 30 includes a first connecting portion 31 and at least one second connecting portion 32 connected together. The first connecting portion 31 is connected to the metal layer 12, and the second connecting portion 32 is electrically connected to the electrode lead-out portion 2011. The first connecting portion 31 includes a first connecting sub-portion 311, which covers the surface of the transition portion 1212 facing away from the insulating substrate 11. Along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the first connecting sub-portion 311 away from the active material layer 20.

[0212] A portion of the electrode assembly 101 is located inside the housing 200, and another portion is located outside the housing 200; or, the entire electrode assembly 101 is located inside the housing 200.

[0213] In some examples, the first electrode 1 is a positive electrode, the current collector 10 is a positive current collector, the positive current collector adopts a composite current collector 10 structure, and the active material layer 20 is a positive active material layer 20; or, the first electrode 1 is a negative electrode, the current collector 10 is a negative current collector, the negative current collector has a composite current collector 10 structure, and the active material layer 20 is a negative active material layer 20.

[0214] The current collector 10 includes a metal layer 12 and an insulating substrate 11. The current collector 10 has a multilayer structure. The insulating substrate 11 can refer to a component in the current collector 10 made of an insulating material (e.g., the aforementioned polymer substrate). The metal layer 12 can refer to a component in the current collector 10 made of the aforementioned metal material.

[0215] The surface of the insulating substrate 11 is covered with a metal layer 12, and the surface of the metal layer 12 facing away from the insulating substrate 11 is covered with an active material layer 20, so that the insulating substrate 11, the metal layer 12 and the active material layer 20 are stacked, and the stacking direction of the insulating substrate 11, the metal layer 12 and the active material layer 20 is the thickness direction of the current collector 10 (see the Y direction in Figure 7). The active material layer 20 can be directly covered on the surface of the metal layer 12, or other materials (e.g., conductive protective layer 13, etc.) can be covered on the surface of the metal layer 12 before the active material layer 20 is covered.

[0216] In some examples, one surface of the insulating substrate 11 is covered with a metal layer 12.

[0217] In some examples, both opposite surfaces of the insulating substrate 11 are covered with metal layers 12, and at least one of the metal layers 12 has an active material layer 20 covering the surface of the metal layer 12 facing away from the insulating substrate 11.

[0218] The metal layer 12 includes a main body portion 121, which may refer to the main part of the metal layer 12.

[0219] In some examples, the metal layer 12 may have a uniform width structure, and the metal layer 12 is the main body 121.

[0220] In some examples, the edge of the metal layer 12 has a protruding structure (e.g., protrusion 122), and the rest of the metal layer 12, excluding the protruding structure, constitutes the main body 121. Of course, other structures are also possible in other examples.

[0221] In some examples, along the first direction, the main body 121 is divided into two parts: a portion covered by the active material layer 20 is the conductive portion 1211, and the portion not covered by the active material layer 20 is the transition portion 1212; the interface between the conductive portion 1211 and the transition portion 1212 can be seen at the end face of the active material layer 20 near the transition portion 1212 (see dashed line G in FIG. 7). The end face of the active material layer 20 near the transition portion 1212 may be thinned to reduce the rolling pressure experienced by this end face during the rolling process, thereby reducing damage to the metal layer 12. The end face of the active material layer 20 near the transition portion 1212 is planar, or approximately a straight line.

[0222] In some examples, the conductive portion 1211 has a uniform width structure, and the transition portion 1212 may have a structure with the same width as the conductive portion 1211.

[0223] The first direction can be a direction perpendicular to the thickness direction of the current collector 10, or a direction that is nearly perpendicular to the current collector 10; the second direction can be a direction perpendicular to both the thickness direction of the current collector 10 and the first direction, or a direction that is nearly perpendicular to both the thickness direction of the current collector 10 and the first direction.

[0224] In some examples, the electrode assembly 101 is a wound structure. When the first electrode 1 is in the unfolded state, the first direction can be referred to as the width direction of the first electrode 1 (refer to the Z direction in Figure 6); the second direction can be referred to as the length direction of the first electrode 1 (refer to the X direction in Figure 6). When the first electrode 1 is in the wound state, the second direction can also be referred to as the winding direction of the first electrode 1 (refer to the direction indicated by arrow V in Figure 4).

[0225] In some examples, the electrode assembly 101 is a stacked structure. The first direction can be the width direction of the first electrode 1 (refer to the Z direction in Figure 6), and the second direction can be the length direction of the first electrode 1 (refer to the X direction in Figure 6). The direction in which the conductive part 1211 points to the transition part 1212 can be referred to as the positive direction of the Z direction in Figure 7; the direction in which the transition part 1212 points to the conductive part 1211 can be referred to as the negative direction of the Z direction in Figure 7.

[0226] The conductive component 30 can refer to a component used to connect the electrode lead-out portion 2011 and the metal layer 12. The conductive component 30 can be made of copper foil or aluminum foil to improve the current carrying capacity of the conductive component 30.

[0227] The electrode lead-out portion 2011 can refer to a metal component used for outputting or inputting electrical energy. The electrode lead-out portion 2011 is connected to an external electronic device so that the battery cell 100 outputs or inputs electrical energy. The electrode lead-out portion 2011 can also be called a terminal post. The electrode lead-out portion 2011 can be provided on the housing 202 or on the end cover 201.

[0228] The conductive member 30 includes a first connecting portion 31 and at least one second connecting portion 32. The first connecting portion 31 may be the portion that guides the conductive member 30 to connect with the metal layer 12, and the second connecting portion 32 may be the portion that guides the conductive member 30 to connect with the electrode lead-out portion 2011. The first connecting portion 31 includes a first connecting sub-portion 311, which may refer to the portion of the first connecting portion 31 that covers the surface of the transition portion 1212 facing away from the insulating substrate 11; the first connecting sub-portion 311 may cover a part of the transition portion 1212 or cover the entire transition portion 1212.

[0229] In some examples, the second connection portion 32 can extend directly from the side of the first connection portion 31 away from the active material layer 20 along the first direction and away from the active material layer 20, so that the second connection portion 32 protrudes outside the insulating substrate 11. That is, along the thickness direction of the current collector 10, the projection of the first connection portion 31 is located within the projection of the metal layer 12, the projection of the second connection portion 32 is located outside the projection range of the metal layer 12, and the projection of the first connection sub-part 311 is located within the projection range of the transition portion 1212. The metal layer 12 and the electrode lead-out portion 2011 are connected at different positions on the conductive member 30, which facilitates connection and reduces mutual influence between the two connections, thus improving connection reliability.

[0230] In some examples, the second connecting part 32 and the electrode lead-out part 2011 can be electrically connected by direct welding, or by welding through conductive parts (e.g., adapter pieces). Welding is a convenient connection method that is easy to manufacture. Of course, other methods can also be used to achieve electrical connection.

[0231] In some examples, when the electrode sheet is wound to form the electrode assembly 101, the insulating substrate 11 insulates the two adjacent layers of the metal layer 12, making it difficult for the two adjacent layers of the metal layer 12 to directly connect and conduct current outward through the insulating substrate 11. This results in current being transmitted almost only from the outermost layer of the metal layer 12, causing poor conductivity, low fast-charging performance, and a tendency to cause local overheating, affecting the reliability of the battery cell 100. However, in the battery cell 100 of this application embodiment, the second connecting portion 32 can electrically connect the two adjacent layers of the metal layer 12, thereby breaking the insulation limitation of the insulating substrate 11. This can effectively improve the conductivity of the first electrode sheet 1, improve the fast-charging performance of the battery cell 100, reduce the heat generation of the battery cell 100, and improve the reliability of the battery cell 100.

[0232] In some examples, when electrode sheets are stacked to form electrode assembly 101, the insulating substrate 11 insulates and separates two adjacent metal layers 12, making it difficult for two adjacent metal layers 12 to directly connect and conduct current outward across the insulating substrate 11. This results in current being transmitted almost exclusively from the outermost metal layer 12, leading to poor conductivity, low fast-charging performance, and a tendency to cause localized overheating, thus affecting the reliability of the battery cell 100. However, in the battery cell 100 of this embodiment, the second connecting portion 32 can electrically connect two adjacent metal layers 12, thereby breaking the insulation limitation of the insulating substrate 11. This effectively improves the conductivity of the first electrode 1, enhances the fast-charging performance of the battery cell 100, reduces heat generation in the battery cell 100, and improves the reliability of the battery cell 100.

[0233] The first insulating element 41 is made of insulating material, such as PP (polypropylene), PET (polyethylene terephthalate), etc. The first insulating element 41 may be, but is not limited to, an insulating coating, insulating adhesive (e.g., hot melt adhesive), or insulating tape.

[0234] In some examples, the first insulating member 41 can be fixed to the first connecting part 311 by means of adhesive or static adsorption.

[0235] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the first connector portion 311 away from the active material layer 20; of the two sides of the first connector portion 311 that are oppositely distributed along a first direction, the side away from the active material layer 20 may be the edge of the first connector portion 311 away from the active material layer 20. Along the thickness direction of the current collector 10, the projection of the edge of the first connector portion 311 away from the active material layer 20 lies within the projection of the first insulating member 41.

[0236] By adopting the technical solution of this embodiment, the first insulating member 41 can block the burrs at the edge of the first connecting part 311 away from the active material layer 20, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100. In addition, the current collector 10 adopts a composite structure of insulating substrate 11 and metal layer 12. Compared with the pure metal current collector 10, the metal layer 12 has a smaller thickness, and the burrs generated by the current collector 10 during the manufacturing process are smaller, which reduces the internal short circuit risk of the battery cell 100 and helps to improve the reliability of the battery cell 100.

[0237] During the use of some battery cells 100, the edge of the first connector 311 away from the active material layer 20 may be impacted, resulting in metal debris. The metal debris falls between the first electrode 1 and the second electrode 2, increasing the risk of short circuit in the battery cell 100 and reducing its reliability. In the battery cell 100 of the present application embodiment, the first insulating member 41 can block the metal debris, reduce the risk of short circuit in the battery cell 100, and improve the reliability of the battery cell 100.

[0238] In some embodiments, as shown in Figures 6 and 7, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the first connecting portion 311 near the edge of the active material layer 20.

[0239] In some examples, of the two sides of the first connector 311 that are opposite each other along a first direction, the side closer to the active material layer 20 may refer to the edge of the first connector 311 near the active material layer 20. Along the thickness direction of the current collector 10, the projection of the edge of the first connector 311 near the active material layer 20 lies within the projection of the first insulating member 41.

[0240] In some examples, along the first direction, the opposite sides of the first insulating member 41 protrude from the opposite two edges of the first connecting part 311; along the thickness direction of the current collector 10, the projection of the first connecting part 311 is located within the projection of the first insulating member 41, so that the first insulating member 41 can cover the entire first connecting part 311, thereby achieving insulation of the entire first connecting part 311.

[0241] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edge of the first connecting part 311 near the active material layer 20, thereby blocking the burrs at the edge of the first connecting part 311 near the active material layer 20, reducing the short circuit risk of the battery cell 100, and improving the reliability of the battery cell 100. In addition, the first insulating member 41 can cover the entire first connecting part 311, realizing the overall insulation of the first connecting part 311, which can effectively reduce the short circuit of the battery cell 100 and improve the reliability of the battery cell 100.

[0242] In some embodiments, referring to FIG12, along the first direction, the edge of the transition portion 1212 away from the conductive portion 1211 is flush with the edge of the first connector portion 311 away from the active material layer 20.

[0243] In some examples, in the two sides of the transition portion 1212 that are oppositely distributed along the first direction, the side away from the conductive portion 1211 may refer to the edge of the transition portion 1212 that is away from the conductive portion 1211.

[0244] Along the thickness direction of the current collector 10, the projection of the edge of the transition portion 1212 away from the active material layer 20 coincides with the edge of the first connecting portion 311 away from the active material layer 20, so that the side of the first connecting portion 311 away from the active material layer 20 is flush with the side of the transition portion 1212 away from the active material layer 20.

[0245] In the fabrication process of some first electrode plates 1, the conductive component 30 is connected to the metal layer 12 of the current collector 10. The conductive component 30 and the current collector 10 are cut to obtain the transition portion 1212 and the first connecting portion 311. The side of the transition portion 1212 away from the active material layer 20 and the side of the first connecting portion 311 away from the active material layer 20 are cut at the same time, so that the side of the first connecting portion 311 away from the active material layer 20 is flush with the side of the transition portion 1212 away from the active material layer 20.

[0246] By adopting the technical solution of this embodiment, along the first direction, the edge of the transition portion 1212 away from the conductive portion 1211 is flush with the edge of the first connecting portion 311 away from the active material layer 20. The structure of the first electrode 1 is regular, which is convenient for processing and manufacturing. It can also reduce the redundancy of the first connecting portion 311 or the transition portion 1212, save space, and improve the energy density of the battery cell 100. In addition, the first insulating member 41 also protrudes from the edge of the transition portion 1212 away from the active material layer 20, blocking burrs, metal debris and other components at the edge of the transition portion 1212 away from the active material layer 20, reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0247] In some embodiments, referring to FIG8, the size of the conductive portion 1211 is L1 and the size of the transition portion 1212 is L2 along the second direction, 0.8≤L2 / L1≤1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0248] 0.8≤L2 / L1≤1, along the second direction, the size of the transition portion 1212 is less than or equal to the size of the conductive portion 1211, and the size of the transition portion 1212 is greater than or equal to more than 0.8 times the size of the conductive portion 1211, so that the size of the transition portion 1212 is not much different from or equal to the size of the conductive portion 1211. The larger the size of the transition portion 1212, the larger the connection area between the transition portion 1212 and the first connecting sub-portion 311 can be set, and the better the current carrying capacity between the transition portion 1212 and the first connecting sub-portion 311.

[0249] 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.

[0250] In some examples, 0.8≤L2 / L1<1, along the second direction, the transition portion 1212 may be located in the middle of the conductive portion 1211, and the two ends of the transition portion 1212 are not flush with the conductive portion 1211.

[0251] In some examples, 0.8≤L2 / L1<1, along the second direction, the transition portion 1212 is provided with one end that may also be biased toward the conductive portion 1211, such that one end of the transition portion 1212 is flush with the conductive portion 1211, while the other end is not flush, or neither end is flush.

[0252] In some examples, L2 = L1, in the second direction, the size of the transition portion 1212 is equal to the size of the conductive portion 1211, in the second direction, the two ends of the transition portion 1212 are flush with the conductive portion 1211, and the transition portion 1212 and the conductive portion 1211 are of equal length.

[0253] By adopting the technical solution of this embodiment, the design of 0.8≤L2 / L1≤1 makes the size of the transition portion 1212 along the second direction large, which is beneficial to increasing the connection area between the first connecting sub-part 311 and the transition portion 1212, increasing the current carrying capacity between the first connecting sub-part 311 and the transition portion 1212, increasing the current carrying capacity of the first electrode 1, reducing the heat generation of the battery cell 100, and improving the fast charging performance of the battery cell 100.

[0254] In some embodiments, as shown in Figures 7-9, the first connection portion 31 is welded to the surface of the metal layer 12 facing away from the insulating substrate 11 to form a first solder mark 51. Along the first direction, the first solder mark 51 is located on the side of the active material layer 20 near the transition portion 1212.

[0255] The first connecting part 31 is welded to the side of the metal layer 12 located near the transition part 1212 of the active material layer 20, and the weld mark formed by the welding is the first weld mark 51; the first weld mark 51 can be a single weld mark or can be composed of multiple weld marks. The first connecting part 311 can be welded to the transition part 1212 or not.

[0256] By adopting the technical solution of this embodiment, the first connection part 31 is welded to the metal layer 12. The welding operation is simple and convenient for the fabrication and processing of the first electrode 1. The first solder mark 51 is located on the side of the active material layer 20 near the transition part 1212, so that the first solder mark 51 is spaced from the active material layer 20, reducing the risk of poor soldering of the first connection part 31 and the metal layer 12 caused by the active material layer 20, which is beneficial to improving the reliability of the battery cell 100.

[0257] In some embodiments, as shown in FIG7, the first insulating element 41 covers at least a portion of the first solder mark 51.

[0258] The first insulating element 41 may cover a portion of the first solder mark 51 or the entire first solder mark 51.

[0259] By adopting the technical solution of this embodiment, the first insulating component 41 can block burrs, metal debris and other components on the first solder mark 51, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0260] In some embodiments, as shown in Figures 7-9, the first solder mark 51 includes a first solder mark portion 511, and a first connecting portion 311 is soldered to the surface of the transition portion 1212 facing away from the insulating substrate 11 to form the first solder mark portion 511.

[0261] The first connecting part 311 is welded to the surface of the transition part 1212 facing away from the insulating substrate 11, and the weld mark formed by the welding is the first weld mark part 511.

[0262] By adopting the technical solution of this embodiment, the first connecting part 311 is welded to the transition part 1212, so that the current can flow directly through the transition part 1212 to the conductive member 30, which is beneficial to improve the overcurrent capacity of the first electrode 1 and improve the fast charging performance of the battery cell 100.

[0263] In some embodiments, referring to FIG8, the size of the transition portion 1212 is L2 and the size of the first solder mark portion 511 is L3 along the second direction, 0.8≤L3 / L2≤1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0264] 0.8≤L3 / L2≤1, along the second direction, the size L3 of the first solder mark 511 can be less than or equal to the size L2 of the transition part 1212, the size L3 of the first solder mark 511 is greater than or equal to more than 0.8 times the size L2 of the transition part 1212, the size L3 of the first solder mark 511 exceeds more than half of the size L2 of the transition part 1212, the longer the size L3 of the first solder mark 511, the larger the welding area between the transition part 1212 and the first connecting part 311, and the better the current carrying capacity at the connection between the transition part 1212 and the first connecting part 311.

[0265] In some examples, 0.8≤L3 / L2<1, along the second direction, the first solder mark 511 may be located in the middle of the transition portion 1212, and the two opposite edges of the first solder mark 511 are not flush with the two opposite sides of the transition portion 1212.

[0266] In some examples, 0.8≤L3 / L2<1, along the second direction, the first solder mark 511 is disposed at one end that may also be biased toward the transition portion 1212, such that one edge of the first solder mark 511 is flush with one side of the transition portion 1212, and the other edge of the first solder mark 511 is not flush with the other side of the transition portion 1212.

[0267] In some examples, L3 = L2, along the second direction, the size L3 of the first solder mark 511 is equal to the size L2 of the transition portion 1212, and the opposite two edges of the first solder mark 511 are flush with the opposite two sides of the transition portion 1212.

[0268] 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.

[0269] By adopting the technical solution of this embodiment, the design of 0.8≤L3 / L2≤1 makes the size of the first soldering part 511 larger along the second direction, which is beneficial to increase the connection area between the first connecting part 311 and the transition part 1212, increase the current carrying capacity at the connection between the first connecting part 311 and the transition part 1212, increase the current carrying capacity of the first electrode 1, reduce the heat generation of the battery cell 100, and improve the fast charging performance of the battery cell 100.

[0270] In some embodiments, as shown in FIG7, the first insulating member 41 covers at least a portion of the first solder mark 511.

[0271] In some examples, the first insulating element 41 covers a portion of the first solder mark 511; for example, along the thickness direction of the current collector 10, the projection of the first insulating element 41 coincides with the projection portion of the first solder mark 511.

[0272] In some examples, the first insulating element 41 covers the entire first solder mark 511; for example, along the thickness direction of the current collector 10, the projection of the first solder mark 511 falls within the projection range of the first insulating element 41.

[0273] By adopting the technical solution of this embodiment, the first insulating component 41 can block burrs, metal debris and other components on the first soldering part 511, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0274] In some embodiments, referring to Figures 6-9, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the first solder mark portion 511 near the edge of the active material layer 20; and / or, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the first solder mark portion 511 away from the edge of the active material layer 20.

[0275] In the two edges of the first solder mark 511 that are distributed opposite to each other along the first direction, the edge closer to the active material layer 20 is the edge of the first solder mark 511 that is close to the active material layer 20, and the edge farther away from the active material layer 20 is the edge of the active material layer 20 of the first solder mark 511.

[0276] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the first solder mark portion 511 near the edge of the active material layer 20.

[0277] Along the thickness direction of the current collector 10, the projection of the first solder mark 511 near the edge of the active material layer 20 is located within the projection of the first insulating member 41, and the first insulating member 41 covers the edge of the first solder mark 511 near the active material layer 20; the first insulating member 41 can block burrs, metal debris and other components at the edge of the first solder mark 511 near the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0278] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the first solder portion 511 away from the active material layer 20.

[0279] Along the thickness direction of the current collector 10, the projection of the edge of the first solder mark 511 away from the active material layer 20 is located within the projection of the first insulating member 41, and the first insulating member 41 covers the edge of the first solder mark 511 away from the active material layer 20; the first insulating member 41 can block burrs, metal debris and other components at the edge of the first solder mark 511 away from the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0280] For example, the first insulating member 41 covers the first solder mark 511. The first insulating member 41 can extend from the first solder mark 511 away from the active material layer 20 until it protrudes from the edge of the first connector 311 away from the active material layer 20, such that the first insulating member 41 covers the edge of the first connector 311 away from the active material layer 20.

[0281] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the first solder mark 511 near the edge of the active material layer 20; along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the first solder mark 511 away from the edge of the active material layer 20.

[0282] For example, along the thickness direction of the current collector 10, the projection of the first solder mark 511 is located inside the first insulating member 41. The first insulating member 41 covers the entire first solder mark 511, thereby blocking burrs, metal debris and other components on the entire first solder mark 511, thus effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0283] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the first soldering portion 511 that are relatively distributed along the first direction, and can block burrs, metal debris and other components at the edges of the first soldering portion 511 that are relatively distributed along the first direction, thereby effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0284] In some embodiments, as shown in Figures 8 and 9, along a first direction, the edge of the first solder mark 511 away from the active material layer 20 is flush with the edge of the first connector 311 away from the active material layer 20.

[0285] In some examples, along the thickness direction of the current collector 10, the projection of the edge of the first solder mark 511 away from the active material layer 20 coincides with the edge of the first connector 311 away from the active material layer 20, so that the side of the first connector 311 away from the active material layer 20 is flush with the edge of the first solder mark 511 away from the active material layer 20.

[0286] In the fabrication process of some first electrode 1, the conductive component 30 is soldered to the metal layer 12 of the current collector 10 and forms a uniform width solder mark extending along the second direction. During the cutting process of the first electrode 1, it can be cut along the second direction on the uniform width solder mark to obtain the first connecting part 311 and the first solder mark part 511. Cutting along the second direction on the uniform width solder mark allows the edge of the first solder mark part 511 away from the active material layer 20 and the side of the first connecting part 311 away from the active material layer 20 to be cut simultaneously, so that the side of the first connecting part 311 away from the active material layer 20 is flush with the edge of the first solder mark part 511 away from the active material layer 20. The first solder mark 511 is cut at the edge away from the active material layer 20, which may result in large burrs at the edge of the first solder mark 511 away from the active material layer 20, increasing the risk of short circuit in the battery cell 100. The first insulating member 41 protrudes from the edge of the first connector 311 away from the active material layer 20, and the first insulating member 41 also protrudes from the edge of the first solder mark 511 away from the active material layer 20. The first insulating member 41 can cover the edge of the first solder mark 511 away from the active material layer 20, thereby blocking the burrs at the edge of the first solder mark 511 away from the active material layer 20, reducing the risk of short circuit in the battery cell 100, and improving the reliability of the battery cell 100.

[0287] By adopting the technical solution of this embodiment, along the first direction, the edge of the first soldering portion 511 away from the active material layer 20 is flush with the edge of the first connecting portion 311 away from the active material layer 20. The structure of the first electrode 1 is regular, which can facilitate the processing and manufacturing of the first electrode 1, reduce the redundancy of the first connecting portion 311, save space, and improve the energy density of the battery cell 100. In addition, the first insulating member 41 also protrudes from the edge of the first soldering portion 511 away from the active material layer 20. The first insulating member 41 can cover the edge of the first soldering portion 511 away from the active material layer 20, thereby blocking the burrs at the edge of the first soldering portion 511 away from the active material layer 20, reducing the short circuit risk of the battery cell 100, and improving the reliability of the battery cell 100.

[0288] In some embodiments, referring to Figures 8 and 9, along the second direction, the two opposite edges of the transition portion 1212 are flush with the two opposite edges of the first connecting portion 311, and the two opposite edges of the first solder portion 511 are flush with the two opposite edges of the first connecting portion 311.

[0289] In some examples, the two sides of the transition portion 1212 that are distributed opposite each other along the second direction can refer to the two opposite edges of the transition portion 1212 along the second direction, and the two sides of the first connecting sub-portion 311 that are distributed opposite each other along the second direction can refer to the two opposite edges of the first connecting sub-portion 311 along the second direction; among the two sides of the transition portion 1212 that are distributed opposite each other along the second direction, the first solder mark portion 511 extends from one side to the other side of the transition portion 1212, wherein the first solder mark portion 511 may extend in a straight line along the second direction, or may extend obliquely or in an arc shape relative to the second direction, etc.; along the second direction, the size of the first solder mark portion 511, the size of the transition portion 1212, and the size of the first connecting sub-portion 311 are equal.

[0290] In some examples, along the thickness direction of the current collector 10, the projections of the two opposite edges of the transition portion 1212 along the second direction, the projections of the two opposite edges of the first connecting portion 311 along the second direction, and the projections of the two opposite edges of the first solder portion 511 along the second direction coincide.

[0291] In the manufacturing process of some first electrode sheets 1, the electrode sheet has solder marks continuously arranged along the second direction. The electrode sheet is cut at intervals along the second direction to obtain multiple first electrode sheets 1. Along the second direction, the two opposite edges of the transition portion 1212 and the two opposite edges of the first connecting portion 311 are cut to make the two opposite edges of the transition portion 1212 flush with the two opposite edges of the first connecting portion 311 along the second direction. The solder marks continuously arranged along the second direction are also cut into multiple first solder mark portions 511, so that the two opposite edges of the first solder mark portions 511 are flush with the two opposite edges of the first connecting portion 311 along the second direction.

[0292] By adopting the technical solution of this embodiment, the structure of the two sides of the first electrode 1 that are relatively distributed along the second direction is regular, which can facilitate the processing and manufacturing of the first electrode 1, reduce the redundancy of the first connecting part 311 and the transition part 1212, save space, and improve the energy density of the battery cell 100. In addition, along the second direction, the size of the first soldering part 511 is equal to the size of the transition part 1212, which increases the welding area between the transition part 1212 and the first connecting part 311, which is beneficial to improving the current carrying capacity of the first electrode 1 and improving the fast charging performance of the battery cell 100.

[0293] In some embodiments, referring to Figures 7-11, the metal layer 12 further includes at least one protrusion 122, and a transition portion 1212 is connected between the protrusion 122 and the conductive portion 1211; along the second direction, the sum of the dimensions of all the protrusions 122 is less than the dimension of the transition portion 1212, and the second direction is perpendicular to the first direction and the thickness direction of the current collector 10; the first connecting portion 31 includes at least one second connecting sub-portion 312, the second connecting sub-portion 312 is connected between the first connecting sub-portion 311 and the second connecting portion 32, the second connecting sub-portion 312 covers the surface of the protrusion 122 facing away from the insulating substrate 11, and the second connecting sub-portion 312 and the protrusion 122 correspond one-to-one.

[0294] Along the first direction, the protrusion 122 can refer to the protruding structure on the side of the main body 121. That is, the protrusion 122 can be obtained by extending outward from the side of the transition portion 1212 away from the conductive portion 1211 along the first direction. The protrusion 122 is not covered by the active material layer 20. The part of the first connecting portion 31 covering the protrusion 122 forms the second connecting sub-part 312. That is, the first connecting portion 31 is divided into two parts along the first direction, of which the part covering the protrusion 122 is the second connecting sub-part 312, and the part covering the transition portion 1212 is the first connecting sub-part 311. The second connecting part 312 is connected between the first connecting part 311 and the second connecting part 32. The interface between the first connecting part 311 and the second connecting part 312 can be seen on the side of the transition part 1212 away from the active material layer 20 (see the dashed line N in FIG12), that is, the side of the protrusion 122 is led out from the transition part 1212. The interface between the second connecting part 312 and the second connecting part 32 can be seen on the side of the protrusion 122 facing away from the transition part 1212 (see the dashed line M in FIG7).

[0295] In some examples, along the second direction, the size of the protrusion 122 is l1, and the number of protrusions 122 is N. Where the number of protrusions 122 is 1, the protrusion 122 and the transition portion 1212 form a stepped structure, and L2 > l1; or the number of protrusions 122 is multiple, the multiple protrusions 122 protrude from the edge of the transition portion 1212 on the same side, the multiple protrusions 122 are spaced apart along the second direction, the multiple protrusions 122 have the same structure, and L2 > N * l1.

[0296] By adopting the technical solution of this embodiment, the size of the protrusion 122 is smaller than that of the transition portion 1212 along the second direction, which can eliminate the side redundancy of the current collector 10, save space, and improve the energy density of the battery cell 100. In addition, the protrusion 122 can also be connected to the second connecting portion 312, thereby increasing the connection area between the metal layer 12 and the first connecting portion 31, improving the overcurrent capacity between the metal layer 12 and the first connecting portion 31, and improving the fast charging performance of the battery cell 100.

[0297] In some embodiments, as shown in Figures 7-11, the first solder mark 51 includes at least one second solder mark portion 512, and the second connecting portion 312 is welded to the corresponding protrusion 122 to form a second solder mark portion 512.

[0298] The second connecting part 312 is welded to the surface of the corresponding protrusion 122 facing away from the insulating substrate 11, and the weld mark formed by the welding is the second weld mark part 512. The second connecting part 312 and the second weld mark part 512 are provided in a one-to-one correspondence.

[0299] In some examples, the first solder mark 51 may only include the second solder mark portion 512, that is, the second connecting portion 312 is welded to the protrusion 122, and the first connecting portion 311 is not welded to the transition portion 1212.

[0300] In some examples, the first solder mark 51 may include a first solder mark portion 511 and a second solder mark portion 512, that is, the first connecting portion 311 is welded to the transition portion 1212, and the second connecting portion 312 is welded to the protrusion 122, which increases the welding area between the first connecting portion 31 and the metal layer 12, which is beneficial to improve the current flow capacity between the first connecting portion 31 and the metal layer 12 and improve the fast charging capability of the battery cell 100.

[0301] In some examples, the first solder mark 511 and the second solder mark 512 can be formed as a single solder mark; for example, the single solder mark can be obtained by cutting the above-mentioned equal-width solder mark, and the dividing line between the first solder mark 511 and the second solder mark 512 can be seen on the side of the second connector 312 away from the active material layer 20.

[0302] In some examples, the first solder mark 511 and the second solder mark 512 may also be two separate solder marks.

[0303] By adopting the technical solution of this embodiment, the second connecting part 312 is welded to the protrusion 122, thereby realizing the connection between the first connecting part 31 and the metal layer 12.

[0304] Of course, in other examples, the first solder mark 51 may only include the first solder mark portion 511, that is, the first connecting portion 311 is welded to the transition portion 1212, and the second connecting portion 312 is not welded to the protrusion portion 122.

[0305] In some embodiments, as shown in Figures 6-9, the first insulating element 41 covers at least a portion of the second solder mark 512.

[0306] In some examples, the first insulating element 41 covers a portion of the second solder mark 512; for example, along the thickness direction of the current collector 10, the projection of the first insulating element 41 coincides with the projection portion of the second solder mark 512.

[0307] In some examples, the first insulating member 41 covers the entire second solder mark 512; for example, along the thickness direction of the current collector 10, the projection of the second solder mark 512 falls within the projection range of the first insulating member 41.

[0308] By adopting the technical solution of this embodiment, the first insulating component 41 can block burrs, metal debris and other components on the second soldering part 512, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0309] In some embodiments, referring to Figures 6-9, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second solder portion 512 near the edge of the active material layer 20; and / or, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the second solder portion 512 away from the edge of the active material layer 20.

[0310] In the two edges of the second solder mark 512 that are distributed opposite to each other along the first direction, the edge closer to the active material layer 20 is the edge of the second solder mark 512 that is close to the active material layer 20, and the edge farther away from the active material layer 20 is the edge of the active material layer 20 of the second solder mark 512.

[0311] In some examples, the first solder mark 511 and the second solder mark 512 form a single solder mark. The edge of the second solder mark 512 near the active material layer 20 coincides with the edge of the first solder mark 511 away from the active material layer 20. That is, the edge of the second solder mark 512 near the active material layer 20 and the edge of the first solder mark 511 away from the active material layer 20 can refer to the boundary line between the first solder mark 511 and the second solder mark 512.

[0312] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second solder portion 512 near the edge of the active material layer 20.

[0313] Along the thickness direction of the current collector 10, the projection of the second solder mark 512 near the edge of the active material layer 20 is located within the projection of the first insulating member 41. The first insulating member 41 covers the edge of the second solder mark 512 near the active material layer 20. The first insulating member 41 can block burrs, metal debris and other components at the edge of the second solder mark 512 near the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0314] For example, a first insulating element 41 covers a first connector portion 311 and extends from the first connector portion 311 away from the active material layer 20 to a second solder pad portion 512, such that the first insulating element 41 covers the second solder pad portion 512 near the edge of the active material layer 20.

[0315] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the second solder portion 512 away from the active material layer 20.

[0316] Along the thickness direction of the current collector 10, the projection of the edge of the second solder mark 512 away from the active material layer 20 is located within the projection of the first insulating member 41. The first insulating member 41 covers the edge of the second solder mark 512 away from the active material layer 20. The first insulating member 41 can block burrs, metal debris and other components at the edge of the second solder mark 512 away from the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0317] For example, a first insulating member 41 covers a first connector portion 311 and extends from the first connector portion 311 away from the active material layer 20 to a second solder portion 512 and beyond the second solder portion 512, such that the first insulating member 41 covers the edge of the second solder portion 512 away from the active material layer 20.

[0318] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second solder portion 512 near the edge of the active material layer 20; along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the second solder portion 512 away from the edge of the active material layer 20.

[0319] For example, along the thickness direction of the current collector 10, the projection of the second solder mark 512 is located inside the first insulating member 41. The first insulating member 41 covers the entire second solder mark 512, thereby blocking burrs, metal debris and other components on the entire second solder mark 512, thus effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0320] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the second soldering part 512 that are relatively distributed along the first direction, and can block burrs, metal debris and other components at the edges of the second soldering part 512 that are relatively distributed along the first direction, thereby effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0321] In some embodiments, referring to Figures 6-9, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second connecting portion 312 near the edge of the active material layer 20; and / or, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the second connecting portion 312 away from the edge of the active material layer 20.

[0322] In the two sides of the second connector 312 that are distributed opposite to each other along the first direction, the side closer to the active material layer 20 is the edge of the second connector 312 near the active material layer 20, and the side away from the active material layer 20 is the edge of the active material layer 20 of the second connector 312.

[0323] In some examples, the first connecting sub-part 311, the second connecting sub-part 312, and the second connecting part 32 are an integrated structure. The side of the second connecting sub-part 312 near the active material layer 20 coincides with the side of the first connecting sub-part 311 away from the active material layer 20. The side of the second connecting sub-part 312 near the active material layer 20 and the side of the first connecting sub-part 311 away from the active material layer 20 can refer to the interface between the first connecting sub-part 311 and the second connecting sub-part 312. The side of the second connecting part 32 near the active material layer 20 coincides with the side of the second connecting sub-part 312 away from the active material layer 20. The side of the second connecting part 32 near the active material layer 20 and the side of the second connecting sub-part 312 away from the active material layer 20 can refer to the interface between the second connecting part 32 and the second connecting sub-part 312.

[0324] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second connecting portion 312 near the edge of the active material layer 20.

[0325] Along the thickness direction of the current collector 10, the projection of the second connecting part 312 near the edge of the active material layer 20 is located within the projection of the first insulating member 41, and the first insulating member 41 covers the edge of the second connecting part 312 near the active material layer 20; the first insulating member 41 can block burrs, metal debris and other components at the edge of the second connecting part 312 near the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0326] For example, a first insulating member 41 covers a first connector portion 311 and extends from the first connector portion 311 away from the active material layer 20 to a second connector portion 312, such that the first insulating member 41 covers the second connector portion 312 near the edge of the active material layer 20.

[0327] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the edge of the second connecting portion 312 away from the active material layer 20.

[0328] Along the thickness direction of the current collector 10, the projection of the edge of the second connector 312 away from the active material layer 20 is located within the projection of the first insulating member 41, and the first insulating member 41 covers the edge of the second connector 312 away from the active material layer 20; the first insulating member 41 can block burrs, metal debris and other components at the edge of the second connector 312 away from the active material layer 20, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0329] For example, a first insulating member 41 covers a first connector portion 311 and extends from the first connector portion 311 away from the active material layer 20 to a second connector portion 312 and beyond the second connector portion 312, such that the first insulating member 41 covers the edge of the second connector portion 312 away from the active material layer 20.

[0330] In some examples, along the direction from the transition portion 1212 to the conductive portion 1211, the first insulating member 41 protrudes from the second connecting portion 312 near the edge of the active material layer 20; along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 protrudes from the second connecting portion 312 away from the edge of the active material layer 20.

[0331] For example, along the thickness direction of the current collector 10, the projection of the second connecting part 312 is located inside the first insulating member 41. The first insulating member 41 covers the entire second connecting part 312, thereby blocking burrs, metal debris and other components on the entire second connecting part 312, thereby effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0332] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the second connecting part 312 that are relatively distributed along the first direction, and can block burrs, metal debris and other components at the edges of the second connecting part 312 that are relatively distributed along the first direction, thereby effectively reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0333] In some embodiments, as shown in Figures 6-9, the first insulating member 41 includes a first insulating portion 4121 and at least one second insulating portion 4122. The first insulating portion 4121 covers the first connecting portion 311, and the second insulating portion 4122 covers the second connecting portion 312. The second insulating portion 4122 corresponds to the second connecting portion 312 one by one.

[0334] In some examples, the portion of the first insulating member 41 covering the first connecting sub-part 311 is the first insulating portion 4121, and the portion of the first insulating member 41 covering the second connecting sub-part 312 is the second insulating portion 4122. The first insulating portion 4121 and the second insulating portion 4122 are arranged along a first direction, with the first insulating portion 4121 being closer to the active material layer 20 than the second insulating portion 4122. The number of second insulating portions 4122 is the same as the number of second connecting sub-parts 312, and the second insulating portions 4122 are correspondingly covered on the second connecting sub-parts 312. The interface between the first insulating portion 4121 and the second insulating portion 4122 can be seen on the side of the second connecting sub-part 312 away from the active material layer 20 (see the dashed line N in Figure 12).

[0335] By adopting the technical solution of this embodiment, the first insulating member 41 can cover the first connecting part 311 and the second connecting part 312, thereby increasing the coverage area of ​​the first insulating member 41, improving the insulation effect of the first insulating member 41, reducing the short circuit risk of the battery cell 100, and improving the reliability of the battery cell 100.

[0336] In some embodiments, referring to FIG6, at least one side of the opposite two sides of the first insulating portion 4121 protrudes from the side corresponding to the first connecting portion 311 along the second direction.

[0337] In the two sides of the first insulating portion 4121 that are distributed opposite each other along the second direction, one side protrudes from the side of the first connecting portion 311 that is on the same side, and the other side protrudes from or does not protrude from the other side of the first connecting portion 311.

[0338] During the manufacturing process of some first electrode sheets 1, after the electrode sheet is cut, burrs may be generated on the side of the first connecting part 311 along the second direction, which may cause the battery cell 100 to short circuit; in particular, the second solder part 512 obtained after cutting may cause large burrs to be generated on the side of the first connecting part 311 along the second direction, which increases the risk of short circuit of the battery cell 100.

[0339] By adopting the technical solution of this embodiment, the first insulating part 4121 can block the burrs on the side of the first connecting part 311 along the second direction, thereby reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0340] In some embodiments, referring to Figures 6-9, there are multiple protrusions 122 and multiple second connecting sub-parts 312. The multiple protrusions 122 are spaced apart along the second direction, and the multiple second connecting sub-parts 312 are spaced apart along the second direction. The multiple protrusions 122 and the multiple second connecting sub-parts 312 are arranged in a one-to-one correspondence. There are multiple second connecting parts 32, which are spaced apart along the second direction. The second connecting sub-parts 312 are connected to each other in a one-to-one correspondence. The multiple second connecting sub-parts 312 are connected to the edge of the first connecting sub-part 311 facing away from the active material layer 20. The first connecting sub-parts 311 are arranged continuously along the second direction. There are multiple second insulating parts 4122, which are arranged along the second direction. The second insulating parts 4122 are arranged in a one-to-one correspondence with the second connecting sub-parts 312.

[0341] In some examples, there are multiple protrusions 122, which are spaced apart along the second direction. Each protrusion 122 covers a corresponding second connecting portion 312, and each second connecting portion 312 is connected to a corresponding second connecting portion 32. The multiple second connecting portions 32 are spaced apart along the second direction, and each second connecting portion 312 covers a corresponding second insulating portion 4122. After the electrode sheet is wound, the multiple protrusions 122 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.

[0342] By adopting the technical solution of this embodiment, the first connecting sub-part 311 is continuously arranged along the second direction, and multiple second connecting sub-parts 312 can be connected into a whole. The first connecting sub-part 311 can provide good support for the second connecting sub-parts 312, which can reduce the risk of the second connecting sub-part 312 bending and inserting the first electrode 1 and the second electrode 2, reduce the short circuit risk of the battery cell 100, and help improve the reliability of the battery cell 100. Along the second direction, the first connecting sub-part 311 is large in size, which helps to increase the welding area between the first connecting sub-part 311 and the transition part 1212, and helps to improve the welding area between the first connecting sub-part 311 and the transition part 1212. The current-carrying capacity of the first electrode 1 is improved, thereby enhancing the fast-charging performance and reliability of the battery cell 100. Multiple protrusions 122 are spaced apart along the second direction, which helps to divide the main body 121 into multiple regions along the second direction. Each region corresponds to one protrusion 122, and electrons in each region can be transferred to the electrode lead-out portion 2011 via the corresponding protrusion 122. This enables regional electron transfer in the main body 121, and the electron transfer path from each region to the corresponding protrusion 122 is short, which helps to reduce the electron transfer distance, lower the overall resistance of the first electrode 1, and improve the fast-charging performance and reliability of the battery cell 100.

[0343] In some embodiments, as shown in FIG6, two adjacent second insulating portions 4122 are connected together.

[0344] In some examples, the sides of two adjacent second insulating portions 4122 are connected to each other to form a whole.

[0345] In some examples, the first insulating member 41 extends along the second direction and has a uniform width structure. The first insulating member 41 is divided into two parts in the first direction, wherein the part closer to the active material layer 20 is the first insulating part 4121, and the part away from the active material layer 20 can be divided into a plurality of second insulating parts 4122 along the second direction. The plurality of second insulating parts 4122 are connected sequentially along the second direction to form an integral structure.

[0346] By adopting the technical solution of this embodiment, two adjacent second insulating parts 4122 can be directly connected to form an integral structure, which facilitates the installation of the first insulating member 41; at the same time, the second insulating part 4122 can also cover the two opposite edges of the second connecting part 312 along the second direction, blocking the sharp protrusions, metal debris and other components on the opposite sides of the second connecting part 312 along the second direction, thereby reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0347] In some embodiments, as shown in Figures 8 and 9, the first solder mark 51 and the active material layer 20 are spaced apart along a first direction.

[0348] Along the thickness direction of the current collector 10, the projection of the first solder mark 51 does not coincide with the projection of the active material layer 20.

[0349] In some examples, the first electrode 1 is a positive electrode, and there is a gap between the first solder mark 51 and the active material layer 20. This gap can be used to provide space between the first connector 311 and the active material layer 20, so as to reduce the risk of lithium plating on the first electrode 1 due to contact between the first connector 311 and the active material layer 20. In addition, it can also provide space between the first solder mark 51 and the side of the first connector 311 near the active material layer 20, so that the first solder mark 51 will not extend to the side of the first connector 311 near the active material layer 20, reducing the risk of the first connector 311 being welded through or cracked near the active material layer 20. This is beneficial to reduce burrs, metal debris and other parts generated by welding, and to improve the reliability of the battery cell 100.

[0350] In some examples, the first electrode 1 is a negative electrode, and there is a gap between the first solder mark 51 and the active material layer 20. This gap provides space between the first solder mark 51 and the side of the first connector 311 near the active material layer 20, preventing the first solder mark 51 from extending to the side of the first connector 311 near the active material layer 20. This reduces the risk of the first connector 311 being welded through or cracked near the active material layer 20, and helps to reduce burrs, metal debris, and other parts generated during welding, thereby improving the reliability of the battery cell 100. The first connector 311 can be connected to the active material layer 20 or spaced apart.

[0351] By adopting the technical solution of this embodiment, there is a gap between the first solder mark 51 and the active material layer 20, so that the welding of the first connection part 31 and the metal layer 12 will not be welded to the active material layer 20, reducing the risk of poor welding between the first connection part 31 and the metal layer 12 and improving the reliability of the battery cell 100.

[0352] In some embodiments, referring to Figures 8 and 9, the distance between the first solder mark 51 and the active material layer 20 along the first direction is S1, wherein 0.3 mm ≤ S1 ≤ 5 mm.

[0353] In some examples, the first solder mark 51 includes only the first solder mark portion 511, and S1 is the distance from the first solder mark portion 511 to the active material layer 20.

[0354] In some examples, the first solder mark 51 includes only the second solder mark portion 512, and S1 is the distance from the second solder mark portion 512 to the active material layer 20.

[0355] In some examples, the first solder mark 51 includes a first solder mark portion 511 and a second solder mark portion 512, and S1 is the distance from the first solder mark portion 511 to the active material layer 20.

[0356] The design with S1≥0.3mm ensures that there is a gap between the first solder mark 51 and the active material layer 20, preventing the first connection part 31 from being soldered to the active material layer 20 and reducing the risk of poor soldering between the first connection part 31 and the metal layer 12. The design with S1≤5mm ensures that the gap between the first solder mark 51 and the active material layer 20 is not too large, which is beneficial to increasing the coverage area of ​​the active material layer 20 on the metal layer 12 and improving the energy density of the battery cell 100.

[0357] The value of S1 can be 0.3mm, 5mm, or any value between 0.3mm and 5mm. For example, the value of S1 can be, but is not limited to, 0.3mm, 0.5mm, 1mm, 2mm, 2.5mm, 2.8mm, 3mm, 4mm, and 5mm.

[0358] By adopting the technical solution of this embodiment, the design of 0.3mm≤S1≤5mm ensures that the first solder mark 51 will not be soldered to the active material layer 20, reducing the risk of poor soldering between the first connection part 31 and the metal layer 12, which is beneficial to improving the connection reliability between the first connection part 31 and the metal layer 12, and improving the reliability of the battery cell 100. In addition, the spacing between the active material layer 20 and the first solder mark 51 is reasonable, and the active material layer 20 and the first solder mark 51 are relatively close. Therefore, with the size of the metal layer 12 in the first direction being fixed, the active material layer 20 can cover a larger area, which is beneficial to improving the energy density of the battery cell 100.

[0359] In some embodiments, 0.5mm ≤ S1 ≤ 2.8mm.

[0360] By adopting the technical solution of this embodiment, the design of 0.5mm≤S1≤2.8mm makes the distance between the active material layer 20 and the first solder mark 51 more reasonable, which can better balance the connection reliability of the first connection part 31 and the energy density of the battery cell 100.

[0361] In some embodiments, as shown in Figures 7-9, the electrode assembly 101 includes a second insulating member 42, which covers the surface of the metal layer 12 facing away from the insulating substrate 11, and the entire second insulating member 42 is located between the first solder mark 51 and the active material layer 20.

[0362] The second insulating component 42 may refer to a component made of insulating material, such as PP (polypropylene), PET (polyethylene terephthalate), etc. The second insulating component 42 may be, but is not limited to, an insulating coating, insulating adhesive (e.g., hot melt adhesive), or insulating tape.

[0363] The second insulating element 42 covers the portion of the metal layer 12 located between the first solder mark 51 and the active material layer 20.

[0364] In some examples, a portion of the second insulating element 42 may be located between the first connector 311 and the metal layer 12, and another portion of the second insulating element 42 may be located between the first connector 311 and the active material layer 20; or, the entire second insulating element 42 may be located between the first connector 311 and the active material layer 20.

[0365] By adopting the technical solution of this embodiment, the second insulating element 42 covers the portion of the metal layer 12 located between the first solder mark 51 and the active material layer 20, which can achieve insulation of this portion, thereby reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0366] In some embodiments, referring to FIG12, the first connecting portion 311 is disposed at a distance from the active material layer 20 along the first direction.

[0367] Along the thickness direction of the current collector 10, the projection of the first connecting part 311 does not coincide with the projection of the active material layer 20.

[0368] By adopting the technical solution of this embodiment, the first connecting part 311 does not contact the active material layer 20, which can reduce the mutual influence between the two and help improve the performance of the battery cell 100.

[0369] In some embodiments, at least a portion of the second insulating member 42 is located between the first connecting portion 311 and the active material layer 20.

[0370] In some examples, a portion of the second insulating element 42 is located within the space between the first connector 311 and the active material layer 20, while another portion of the second insulating element 42 is located between the first connector 311 and the metal layer 12.

[0371] In some examples, the entire second insulating element 42 is located within the space formed by the first connector 311 and the active material layer 20, and the second insulating element 42 does not extend between the first connector 311 and the metal layer 12. This facilitates the spacing between the first solder mark 51 and the second insulating element 42, reducing the risk of poor soldering between the first connector 31 and the metal layer 12.

[0372] In some battery cells 100, the second connecting portion 32 is bent before being connected to the electrode lead-out portion 2011. During the bending of the second connecting portion 32, the transition portion 1212 is also bent, which may cause cracks or other problems in the part of the transition portion 1212 located between the first connecting portion 311 and the active material layer 20. The second insulating member 42 covers the part of the transition portion 1212 located between the first connecting portion 311 and the active material layer 20. The second insulating member 42 can provide support for this part, thereby reducing the risk of cracks in this part. In addition, the second insulating member 42 covering the part of the transition portion 1212 located between the first connecting portion 311 and the active material layer 20 can also achieve insulation of this part, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0373] In some embodiments, referring to Figures 5-7, the electrode assembly 101 further includes a second electrode 2 with a polarity opposite to that of the first electrode 1. The second electrode 2 includes a main functional portion 210 and an electrode tab 220 arranged along a first direction. The end of the main functional portion 210 near the transition portion 1212 has a first end face 2101, and the electrode tab 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.

[0374] The main functional part 210 may refer to the main structure of the second electrode 2, and the tab 220 may refer to the protruding structure extending from the end of the main functional part 210 near the transition part 1212. The tab 220 is used to electrically connect with the electrode lead 2011. The conductive member 30 and the tab 220 are electrically connected to the electrode lead 2011 with different polarities to realize the charging and discharging of the battery cell 100.

[0375] Of the two end faces of the main functional part 210 that are distributed opposite each other along the first direction, the end face closer to the transition part 1212 forms the first end face 2101.

[0376] By adopting the technical solution of this embodiment, the first end face 2101 and the second insulating member 42 are disposed opposite to each other. The second insulating member 42 can block the burrs at the first end face 2101, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0377] In some embodiments, referring to FIG7, along a first direction, one side of the first insulating member 41 covers the first connecting sub-part 311, and the other side of the first insulating member 41 covers at least a portion of the second insulating member 42.

[0378] Along the thickness direction of the current collector 10, the projection of the first insulating member 41 coincides with the projection of the second insulating member 42.

[0379] The first insulating element 41 may cover a portion of the second insulating element 42 or cover the entire second insulating element 42.

[0380] In some examples, the first insulating element 41 can be fixed to the second insulating element 42 by adhesive or static adsorption. Of course, in other examples, the first insulating element 41 can also be fixed to the second insulating element 42 in other ways.

[0381] By adopting the technical solution of this embodiment, the first insulating member 41 and the second insulating member 42 can achieve double-layer insulation, reduce the short-circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0382] In some embodiments, referring to FIG13, along a first direction, one side of the first insulating member 41 covers the first connecting portion 311, and the other side of the first insulating member 41 covers at least a portion of the active material layer 20.

[0383] It is understood that, of the two sides of the first insulating member 41 that are distributed opposite each other along the first direction, one side covers the first connecting part 311 and the other side covers at least a portion of the active material layer 20. The first insulating member 41 may cover the end of the active material layer 20 facing the first connecting part 311 or it may cover the entire active material layer 20.

[0384] In some examples, along a first direction, the first insulating member 41 extends from the active material layer 20 to and beyond the first connector portion 311, such that the portion of the metal layer 12 located between the first connector portion 311 and the active material layer 20 is covered by the first insulating member 41, thereby achieving insulation of this portion. The portion of the metal layer 12 located between the first connector portion 311 and the active material layer 20 may be covered by a second insulating member 42, or it may not be covered by the second insulating member 42.

[0385] In some examples, the portion of the metal layer 12 located between the first connector 311 and the active material layer 20 may be covered by a second insulating member 42, and the first insulating member 41 may completely cover the second insulating member 42.

[0386] In some examples, the portion of the metal layer 12 located between the first connector 311 and the active material layer 20 may not cover the second insulating member 42. The first insulating member 41 may cover the portion of the metal layer 12 located between the first connector 311 and the active material layer 20 to achieve insulation in this portion, which is beneficial to improving the reliability of the battery cell 100. In addition, the second insulating member 42 can be omitted, saving costs. At the same time, the active material layer 20 can be used to cover the original position of the second insulating member 42, which increases the coverage area of ​​the active material layer 20 on the metal layer 12, which is beneficial to improving the energy density of the battery cell 100.

[0387] By adopting the technical solution of this embodiment, the first insulating member 41 has a wide coverage area and good insulation effect, which is conducive to improving the reliability of the battery cell 100. The first insulating member 41 can cover the end of the active material layer 20 near the transition portion 1212, which can block the burrs of the active material layer 20 near the transition portion 1212, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0388] In some embodiments, referring to FIG13, the size of the portion of the first insulating member 41 covering the active material layer 20 along the first direction is H, wherein 0.2 mm ≤ H ≤ 1.0 mm.

[0389] The design with H≥0.2mm allows the first insulating member 41 to cover the end of the active material layer 20 near the transition portion 1212. The first insulating member 41 can block burrs at the end of the active material layer 20 near the transition portion 1212, improving the reliability of the battery cell 100. The design with H≤1.0mm ensures that the portion of the first insulating member 41 covering the active material layer 20 is not too large, which helps to reduce the weight and volume of the first insulating member 41 and improve the energy density of the battery cell 100.

[0390] In some examples, the value of H can be 0.2mm, 1mm, or any value between 0.2mm and 1.0mm. For example, the value of H can be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.6mm, 0.8mm, 0.9mm, or 1mm.

[0391] By adopting the technical solution of this embodiment, the size of the portion of the first insulating member 41 covering the active material layer 20 along the first direction is reasonable, which can simultaneously address the issues of blocking burrs at the end of the active material layer 20 near the transition portion 1212 and the energy density of the battery cell 100.

[0392] In some embodiments, 0.3mm ≤ H ≤ 0.8mm.

[0393] By adopting the technical solution of this embodiment, the size of the portion of the first insulating member 41 covering the active material layer 20 along the first direction is more reasonable, which can better take into account both the burrs at the end of the active material layer 20 near the transition portion 1212 and the energy density problem of the battery cell 100.

[0394] In some embodiments, referring to Figures 5 and 12, the electrode assembly 101 further includes a second electrode 2 with a polarity opposite to that of the first electrode 1. The second electrode 2 includes a main functional portion 210 and an electrode tab 220 arranged along a first direction. The end of the main functional portion 210 near the transition portion 1212 has a first end face 2101, and the electrode tab 220 extends outward from the first end face 2101. Along the direction from the conductive portion 1211 toward the transition portion 1212, the side of the first connecting portion 311 away from the active material layer 20 does not protrude from the first end face 2101.

[0395] Along the thickness direction of the current collector 10, the projection of the side of the first connecting part 311 away from the active material layer 20 falls within the projection range of the main functional part 210, so that the first end face 2101 is opposite to the hollow area of ​​the conductive member 30 that does not extend out of the second connecting part 32 or the second connecting part 312.

[0396] By adopting the technical solution 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 cell 100 and improve the reliability of the battery cell 100.

[0397] In some embodiments, as shown in Figures 5 and 12, the projection of the first end face 2101 is located within the projection of the first connecting sub-part 311 along the thickness direction of the current collector 10.

[0398] Along the direction from the conductive part 1211 toward the transition part 1212, the side of the first connecting part 311 away from the active material layer 20 protrudes from the first end face 2101, so that the edge of the first connecting part 311 away from the active material layer 20 is not opposite to the main functional part 210, which can reduce the short circuit risk of the battery cell 100 and help improve the reliability of the battery cell 100.

[0399] In some embodiments, referring to Figures 5 and 7, the electrode assembly 101 further includes a second electrode 2 with a polarity opposite to that of the first electrode 1. The second electrode 2 includes a main functional portion 210 and an electrode tab 220 arranged along a first direction. The end of the main functional portion 210 near the transition portion 1212 has a first end face 2101, and the electrode tab 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 first insulating member 41.

[0400] In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122. Along the thickness direction of the current collector 10, the projection of the first end face 2101 is located within the projection of the first insulating portion 4121. The first end face 2101 is disposed opposite to the first connecting portion 311. In the direction from the conductive portion 1211 to the transition portion 1212, the main functional portion 210 does not protrude beyond the edge of the first connecting portion 311 away from the active material layer 20. Alternatively, the projection of the first end face 2101 is located within the projection of the second insulating portion 4122. The first end face 2101 is disposed opposite to the second insulating portion 4122. In the direction from the conductive portion 1211 to the transition portion 1212, the main functional portion 210 protrudes beyond the edge of the first connecting portion 311 away from the active material layer 20.

[0401] By adopting the technical solution of this embodiment, the first insulating member 41 can block the tip protrusion at the first end face 2101, reduce the short circuit risk of the battery cell 100, and improve the reliability of the battery cell 100.

[0402] In some embodiments, referring to FIG7, there are two metal layers 12, which cover opposite sides of the insulating substrate 11 along the thickness direction of the current collector 10; there are two active material layers 20, which cover the conductive portions 1211 of the two metal layers 12; there are two conductive members 30, whose first connecting portions 31 are connected to the two metal layers 12; and there are two first insulating members 41, which cover the first connecting portions 311 of the two conductive members 30.

[0403] The number of metal layers 12, the number of first insulating elements 41, the number of active material layers 20, and the number of conductive elements 30 are all two. The two metal layers 12 respectively cover the opposite sides of the insulating substrate 11 along the thickness direction, and the two active material layers 20 respectively cover the conductive portions 1211 of the two metal layers 12. The first connecting portion 31 of one conductive element 30 is connected to the surface of one metal layer 12 facing away from the insulating substrate 11, and the first connecting portion 31 of the other conductive element 30 is connected to the surface of the other metal layer 12 facing away from the insulating substrate 11. The two first insulating elements 41 are located on opposite sides of the insulating substrate 11 along the thickness direction and respectively cover the first connecting portions 311 of the two conductive elements 30.

[0404] By adopting the technical solution of this embodiment, the first connecting portions 31 of the two conductive components 30 are respectively welded to the metal layers 12 located on opposite sides of the insulating substrate 11. This allows the second connecting portions 32 of the two conductive components 30 to be connected, thereby making the two metal layers 12 electrically conductive. This breaks the insulation limitation of the insulating substrate 11, effectively improving the conductivity of the first electrode 1, improving the fast charging performance of the battery cell 100, reducing the heat generation risk of the battery cell 100, and improving the reliability of the battery cell 100.

[0405] In some embodiments, referring to FIG6, a portion of the first insulating member 41 protruding from the first connecting portion 311 in the direction from the conductive portion 1211 to the transition portion 1212 forms a blocking portion 4131. The blocking portion 4131 is located on the side of the second connecting portion 32 in a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector 10.

[0406] The blocking portion 4131 may refer to the portion of the first insulating member 41 that protrudes from the edge of the first connecting portion 311 away from the active material layer 20. The blocking portion 4131 is located on one of the two sides of the second connecting portion 32 that are distributed opposite each other along the second direction.

[0407] In some examples, along the thickness direction of the current collector 10, the blocking portion 4131 may refer to the portion of the first insulating member 41 located outside the projection of the metal layer 12.

[0408] In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122. The portions of two adjacent first insulating portions 4121 corresponding to the areas of the first connecting portion 311 where the second connecting portion 312 is not extended form a blocking portion 4131. During the manufacturing or use of the battery cell 100, burrs, metal debris, and other components may be generated in the areas of the first connecting portion 311 where the second connecting portion 312 is not extended, increasing the short-circuit risk of the battery cell 100. The blocking portion 4131 can block these burrs, metal debris, and other components in these areas, reducing the short-circuit risk of the battery cell 100 and improving its reliability.

[0409] By adopting the technical solution of this embodiment, the blocking part 4131 can block burrs, metal debris and other components at the edge of the first connecting part 311 away from the active material layer 20, thereby reducing the short circuit risk of the battery cell 100 and improving the reliability of the battery cell 100.

[0410] In some embodiments, as shown in FIG12, the blocking portions 4131 of the two first insulating members 41 are attached together.

[0411] Along the thickness direction of the current collector 10, two first insulating members 41 are located on opposite sides of the first electrode 1. The blocking portions 4131 of the two first insulating members 41 are offset from the second connecting portion 312 and the second connecting portion 32 of the conductive member 30, so that the blocking portions 4131 of the two first insulating members 41 can be directly attached. The blocking portions 4131 of the two first insulating members 41 can be attached by means of, but not limited to, bonding or static adsorption.

[0412] By adopting the technical solution of this embodiment, after the blocking portions 4131 of the two first insulating members 41 are attached, they can wrap the burrs, metal debris and other components at the edge of the first connecting portion 311 away from the active material layer 20, blocking the burrs at the edge of the first connecting portion 311 away from the active material layer 20, reducing the risk of metal debris falling, reducing the short circuit risk of the battery cell 100, and improving the reliability of the battery cell 100.

[0413] In some embodiments, referring to FIG7, the second connection portion 32 of the two conductive members 30 is welded to form a second solder mark 52.

[0414] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the portion of the conductive member 30 protruding from the side of the protrusion 122 away from the active material layer 20 forms a second connecting portion 32. This allows the second connecting portions 32 of the two conductive members 30 to be directly brought close together and welded, leaving a weld mark known as a second weld mark 52. The second connecting portions 32 of the two conductive members 30 can be welded using methods such as ultrasonic welding or laser welding.

[0415] By adopting the technical solution of this embodiment, the welding of the second connection portion 32 of the two conductive components 30 can electrically connect the metal layers 12 located on opposite sides of the insulating substrate 11, thereby breaking the insulation limitation of the insulating substrate 11, effectively improving the conductivity of the first electrode 1, improving the fast charging performance of the battery cell 100, reducing the heat generation of the battery cell 100, and improving the reliability of the battery cell 100.

[0416] In some embodiments, as shown in FIG7, the first insulating element 41 covers at least a portion of the second solder mark 52.

[0417] The first insulating element 41 may cover a portion of the second solder mark 52, or the first insulating element 41 may cover the entire second solder mark 52.

[0418] By adopting the technical solution of this embodiment, the first insulating component 41 can cover the second solder mark 52, which can block the sharp protrusions, metal debris and other components on the second solder mark 52, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0419] In some embodiments, referring to FIG7, the first insulating member 41 protrudes from the edge of the second solder mark 52 away from the active material layer 20 along the direction from the conductive portion 1211 to the transition portion 1212.

[0420] In the two edges of the second solder mark 52 that are distributed opposite each other along the first direction, the edge that is far away from the active material layer 20 is the edge of the second solder mark 52 that is far away from the active material layer 20.

[0421] In some examples, along the direction from the conductive portion 1211 to the transition portion 1212, the first insulating member 41 can extend from the first connecting portion 311 away from the active material layer 20 to the second connecting portion 32 and protrude from the edge of the second solder mark 52 away from the active material layer 20; that is, along the thickness direction of the current collector 10, the projection of the second solder mark 52 falls within the projection of the first insulating member 41, so that the first insulating member 41 can cover the entire second solder mark 52.

[0422] By adopting the technical solution of this embodiment, the first insulating component 41 can cover the entire second solder mark 52, which can block burrs, metal debris and other components on the second solder mark 52, reduce the short circuit risk of the battery cell 100 and improve the reliability of the battery cell 100.

[0423] In some embodiments, referring to FIG7, the current collector 10 includes a conductive protective layer 13, at least a portion of which is located between the active material layer 20 and the conductive portion 1211.

[0424] In some examples, the conductive protective layer 13 may refer to a conductive structure disposed between the active material layer 20 and the conductive portion 1211. This conductive structure is capable of conducting electricity, allowing electrons to be transferred between the active material layer 20 and the conductive portion 1211, thereby realizing the input or output of electrical energy of the battery cell 100. The conductive protective layer 13 may be a structure of uniform thickness or a structure of unequal thickness.

[0425] For example, a portion of the conductive protective layer 13 is located between the active material layer 20 and the conductive portion 1211, and another portion covers the transition portion 1212 and protrudes beyond the active material layer 20.

[0426] For example, the entire conductive protective layer 13 is located between the active material layer 20 and the conductive portion 1211.

[0427] In some examples, the conductive protective layer 13 may contain conductive carbon black and a binder. On the one hand, it acts as a buffer and lubricant between the active material layer 20 and the conductive part 1211, which can alleviate the damage to the metal layer 12 caused by particles in the active material layer 20 during the rolling process of the first electrode 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 conductive part 1211, which is beneficial to improving the performance of the battery cell 100.

[0428] During the rolling process of the first electrode 1, the metal layer 12 is relatively thin, and the particles in the active material layer 20 can damage the metal layer 12, which can easily lead to cracks in the conductive part 1211. The conductive protective layer 13 of this embodiment can separate the active material layer 20 and the conductive part 1211, and protect the conductive part 1211. This reduces the risk of cracks in the conductive part 1211 caused by rolling the active material layer 20, which is beneficial to improving the electron transport capability of the conductive part 1211 and improving the fast charging performance of the battery cell 100.

[0429] In some embodiments, referring to FIG7, the conductive protective layer 13 protrudes from the active material layer 20 near the end of the first connector 311 in the direction from the conductive portion 1211 to the transition portion 1212.

[0430] In some examples, a portion of the conductive protective layer 13 covers the conductive portion 1211 and another portion covers the transition portion 1212. The conductive protective layer 13 protrudes from the active material layer 20 and can completely separate the metal layer 12 and the active material layer 20. In addition, it can provide an extra-elongated space for the active material layer 20 during the rolling process, which helps to reduce the risk of direct contact between the active material layer 20 and the metal layer 12.

[0431] By adopting the technical solution of this 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 for the metal layer 12, and the first electrode 1 has better overcurrent capacity, which is beneficial to improving the fast charging performance and reliability of the battery cell 100.

[0432] In some embodiments, referring to FIG7, the protrusion length of the conductive protective layer 13 protruding from the active material layer 20 in the direction from the conductive portion 1211 to the transition portion 1212 ranges from 0.3 mm to 0.8 mm.

[0433] The conductive protective layer 13 protrudes from the active material layer 20 by a distance S2, wherein 0.3mm≤S2≤0.8mm, and the value of S2 can be 0.3mm, 0.8mm, or any value between 0.3mm and 0.8mm. For example, the value of S2 can be, but is not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, or 0.8mm.

[0434] The design with S2≥0.3mm allows the conductive protective layer 13 to completely separate the active material layer 20 and the metal layer 12. The conductive protective layer 13 provides better protection for the metal layer 12, and the first electrode 1 has better overcurrent capacity, which is beneficial to improving the fast charging performance and reliability of the battery cell 100. The design with S2≤0.8mm prevents the conductive protective layer 13 from protruding too much from the active material layer 20 and occupying too much space, which is beneficial to saving the internal space of the battery cell 100 and improving the energy density of the battery cell 100.

[0435] By adopting the technical solution of this embodiment, the overcurrent capacity and energy density of the battery cell 100 can be well balanced.

[0436] In some embodiments, the first connection portion 31 is welded to the surface of the metal layer 12 facing away from the insulating substrate 11 to form a first solder mark 51, and the conductive protective layer 13 and the first solder mark 51 are spaced apart along the first direction.

[0437] In some examples, the conductive protective layer 13 is spaced apart from the first connector portion 311, and the second insulating portion 4122 covers the portion of the conductive protective layer 13 located between the first connector portion 311 and the active material layer 20.

[0438] By adopting the technical solution of this embodiment, the first connecting part 31 will not be welded to the conductive protective layer 13, which can reduce the risk of poor soldering between the first connecting part 31 and the metal layer 12 and improve the reliability of the welding between the first connecting part 31 and the metal layer 12.

[0439] In some embodiments, as shown in FIG7, the first insulating member 41 is connected to the first electrode 1.

[0440] In some examples, the first insulating element 41 may be connected to the transition portion 1212, the conductive member 30, or the active material layer 20. The first insulating element 41 may be connected to the first electrode 1 by means of bonding or static adsorption.

[0441] By adopting the technical solution of this embodiment, the first insulating member 41 is connected to the first electrode 1, and the first insulating member 41 can be fixed, thereby stably blocking burrs, metal debris and other components at the edge of the first connecting part 311 away from the active material layer 20, which is beneficial to improving the reliability of the battery cell 100.

[0442] In some embodiments, as shown in Figures 7, 14 and 15, the first insulating member 41 includes an insulating base layer 4111 and an adhesive layer 4112, the adhesive layer 4112 being bonded between the insulating base layer 4111 and the first electrode 1.

[0443] The first insulating element 41 adopts a tape structure; the insulating base layer 4111 can refer to the main body 121 of the first insulating element 41, and the adhesive layer 4112 can refer to the structure formed by the adhesive covering the surface of the insulating base layer 4111. The material of the insulating base layer 4111 can be polyethylene terephthalate, polypropylene, etc. The material of the adhesive layer 4112 can be acrylic, rubber, latex, etc. The structure of the first insulating element 41 can be the same as or different from the structure of the second insulating element 42.

[0444] 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.

[0445] By adopting the technical solution of this embodiment, the first insulating member 41 adopts the structure of tape, which can directly stick the first insulating member 41 to the first electrode 1, reducing the risk of incomplete coverage; the insulating base layer 4111 and the adhesive layer 4112 cover the first electrode 1, blocking burrs on the first electrode 1. The thickness of the insulating base layer 4111 and the thickness of the adhesive layer 4112 do not need to be large, which is beneficial to improving the energy density of the battery cell 100; the insulating base layer 4111 has good structural strength and can stably block burrs on the first electrode 1, improving the reliability of the battery cell 100; the adhesive layer 4112 can stably fix the insulating base layer 4111 to the first electrode 1, reducing the risk of the first insulating member 41 falling off; metal debris on the first electrode 1 can also be adhered to the adhesive layer 4112, which can effectively reduce the risk of metal debris falling off the first electrode 1 and reduce the short circuit risk of the battery cell 100.

[0446] In some embodiments, as shown in Figures 7, 14 and 15, the thickness of the insulating base layer 4111 ranges from 6 μm to 15 μm; and / or, the thickness of the adhesive layer 4112 ranges from 0.5 μm to 3 μm.

[0447] In some examples, the thickness of the insulating base layer 4111 ranges from 6 μm to 15 μm.

[0448] The thickness of the insulating base layer 4111 is T1, 6μm≤T1≤15μm. It can be understood that the value of T1 can be 6μm, 15μm, or any value between 6μm and 15μm. For example, the value of T1 can be, but is not limited to, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, and 16μm.

[0449] The design of T1≥6μm ensures that the insulating base layer 4111 has a certain thickness to block burrs and achieve insulation; the design of T1≤15μm ensures that the thickness of the insulating base layer 4111 is not too large, which is conducive to reducing the volume occupied by the first insulating component 41 and improving the energy density of the battery cell 100.

[0450] By adopting the technical solution of this embodiment, both the internal insulation and energy density of the battery cell 100 can be taken into account.

[0451] In some examples, the thickness of the adhesive layer 4112 ranges from 0.5 μm to 3 μm.

[0452] The thickness of the adhesive layer 4112 is T2, 0.5μm≤T2≤3μm. It can be understood that the value of T2 can be 0.3μm, 3μm, or any value between 0.3μm and 3μm. For example, the value of T2 can be, but is not limited to, 0.3μm, 0.5μm, 1μm, 1.5μm, 2μm, 2.5μm, and 3μm.

[0453] The design with T2≥0.5μm ensures that the adhesive layer 4112 has a certain thickness, allowing the first insulating component 41 to be stably bonded to the first electrode 1, resulting in good insulation reliability of the first insulating component 41. The design with T2≤3μm ensures that the thickness of the adhesive layer 4112 is not too large, which helps to reduce the volume occupied by the first insulating component 41 and improve the energy density of the battery cell 100.

[0454] By adopting the technical solution of this embodiment, the insulation reliability and energy density of the battery cell 100 can be simultaneously taken into account.

[0455] In some examples, the thickness of the insulating base layer 4111 ranges from 6 μm to 15 μm; the thickness of the adhesive layer 4112 ranges from 0.5 μm to 3 μm.

[0456] By adopting the technical solution of this embodiment, the insulation reliability and energy density of the battery cell 100 can be simultaneously taken into account.

[0457] In one embodiment, referring to FIG7, the size of the first insulating member 41 along the first direction is W, wherein 3mm≤W≤9mm.

[0458] In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122, where W is equal to the overall dimension of the first insulating portion 4121 and the second insulating portion 4122 along a first direction.

[0459] 3mm≤W≤9mm. It can be understood that the value of W can be 3mm, 9mm, or any value between 3mm and 9mm. For example, the value of W can be, but is not limited to, 3mm, 4mm, 4.5mm, 5mm, 6mm, 6.5mm, 7mm, 8mm, and 9mm.

[0460] The design with W≥3mm ensures that the first insulating member 41 has a certain size along the first direction. The first insulating member 41 can effectively block the burrs at the edge of the first connector 311 facing away from the active material layer 20, thereby achieving internal insulation of the battery cell 100. The design with W≤9mm ensures that the size of the first insulating member 41 along the first direction is not too large, which is beneficial to reducing the volume occupied by the first insulating member 41 and improving the energy density of the battery cell 100.

[0461] By adopting the technical solution of this embodiment, the insulation reliability and energy density of the battery cell 100 can be simultaneously taken into account.

[0462] In some embodiments, 4.5mm ≤ W ≤ 6.5mm.

[0463] By adopting the technical solution of this embodiment, the size of the first insulating member 41 is more reasonable along the first direction, which can better balance the insulation reliability and energy density of the battery cell 100.

[0464] In some embodiments, as shown in FIG7, the thickness of the conductive portion 1211 is at least partially smaller than the thickness of the transition portion 1212.

[0465] In some examples, the minimum thickness of the conductive part 1211 is t1, and the thickness of the transition part 1212 is t2, where t1 < t2.

[0466] In some examples, the transition portion 1212 is a structure of equal thickness or substantially equal thickness, and the conductive portion 1211 is also a structure of equal thickness or substantially equal thickness, with the thickness of the transition portion 1212 being greater than the minimum thickness of the conductive portion 1211.

[0467] In some examples, the transition portion 1212 is a structure of equal thickness or substantially equal thickness, while the conductive portion 1211 may be a structure of unequal thickness. Along the direction from the conductive portion 1211 to the transition portion 1212, the thickness of the conductive portion 1211 is progressively increased, which may be in a step-like or gradual manner. The thickness of the portion of the conductive portion 1211 away from the transition portion 1212 is less than the thickness of the transition portion 1212.

[0468] By adopting the technical solution of this embodiment, the thickness of the transition portion 1212 can be greater than at least part of the thickness of the conductive portion 1211. The larger thickness of the transition portion 1212 improves the current carrying capacity of the transition portion 1212, reduces the heat generation of the transition portion 1212, reduces the risk of melting of the first insulating member 41, and improves the reliability of the battery cell 100. In addition, the improved current carrying capacity of the transition portion 1212 also helps to improve the fast charging performance of the battery cell 100.

[0469] In some embodiments, referring to FIG7, the conductive portion 1211 includes a first sub-portion 12111 and a second sub-portion 12112. The first sub-portion 12111 is connected between the second sub-portion 12112 and the transition portion 1212. The first sub-portion 12111 and the second sub-portion 12112 are covered with an active material layer 20. The thickness of the first sub-portion 12111 is greater than the thickness of the second sub-portion 12112, and the thickness of the transition portion 1212 is greater than or equal to the thickness of the first sub-portion 12111.

[0470] In some examples, the conductive portion 1211 may be a structure of unequal thickness. Along the direction from the conductive portion 1211 to the transition portion 1212, the conductive portion 1211 is divided into two parts: the part closer to the transition portion 1212 is the first sub-part 12111, and the part farther away from the transition portion 1212 is the second sub-part 12112. Both the first sub-part 12111 and the second sub-part 12112 are covered with an active material layer 20.

[0471] In some examples, the first sub-part 12111 may be a structure of equal thickness, and the second sub-part 12112 may be a structure of equal thickness; the thickness of the first sub-part 12111 is greater than the thickness of the second sub-part 12112, and the thickness of the transition part 1212 is greater than or equal to the thickness of the first sub-part 12111. The thickness of the first sub-part 12111 is t3, and the thickness of the second sub-part 12112 is t4, where t3 > t4, t2 ≥ t3, and t1 = t4; wherein the first sub-part 12111 and the second sub-part 12112 form a stepped structure; the thickness of the transition part 1212 may be equal to the thickness of the first sub-part 12111, such that the transition part 1212 and the first sub-part 12111 form a structure of equal thickness; or, the thickness of the transition part 1212 may be greater than the thickness of the second sub-part 12112, such that the first sub-part 12111 and the transition part 1212 form a stepped structure.

[0472] In some examples, the first sub-part 12111 may also be a multi-segment structure, with the thickness of each segment increasing sequentially along the direction from the conductive part 1211 to the transition part 1212. For example, the first sub-part 12111 includes a first segment and a second segment, with the first segment connecting the second segment and the second sub-part 12112. Along the direction from the conductive part 1211 to the transition part 1212, the thickness of the first segment gradually increases, while the second segment is generally of uniform thickness, equal to the thickness of the transition part 1212, i.e., t3 can be equal to the thickness of the second segment. The thickness of the first segment gradually increases from that of the second sub-part 12112 to the thickness of the second segment. This arrangement allows for a smooth transition between the first segment and the second segment and the second sub-part 12112, which helps reduce stress concentration and improve structural strength. The thickness of the first segment can be equal to the thickness of the transition part 1212, or the thickness of the transition part 1212 can be greater than the thickness of the first segment.

[0473] During the use of the battery cell 100, electrons generated by the active material layer 20 are gradually collected on the transition portion 1212 along the direction from the conductive portion 1211 to the transition portion 1212. More electrons flow through the first sub-part 12111 than through the second sub-part 12112, which requires the current carrying capacity of the first sub-part 12111 to be greater than that of the second sub-part 12112.

[0474] In this embodiment of the application, the thickness of the first sub-part 12111 is greater than the thickness of the second sub-part 12112, which makes the current carrying capacity of the first sub-part 12111 greater than that of the second sub-part 12112. This reduces the limitation on current, improves the current carrying capacity of the first electrode 1, reduces the heat generation of the battery cell 100, and helps to improve the reliability of the battery cell 100.

[0475] In some embodiments, referring to FIG7, the current collector 10 further includes a conductive protective layer 13, which includes a first protective portion 131 and a second protective portion 132. The first protective portion 131 is located between the first sub-part 12111 and the active material layer 20, and the second protective portion 132 is located between the second sub-part 12112 and the active material layer 20. The thickness of the first protective portion 131 is less than the thickness of the second protective portion 132.

[0476] In some examples, along the first direction, the portion of the conductive protective layer 13 located between the first sub-part 12111 and the active material layer 20 can be the first protective part 131, and the portion of the conductive protective layer 13 located between the second sub-part 12112 and the active material layer 20 can be the second protective part 132. The thickness of the first protective part 131 is t5, and the thickness of the second protective part 132 is t6, where t5 < t6, which can reduce the thickness difference of the current collector 10 at the first protective part 131 and the second protective part 132.

[0477] In some examples, the first protective part 131 may be a structure of equal thickness or unequal thickness, and t5 may be the maximum thickness of the first protective part 131; the second protective part 132 may be a structure of equal thickness or unequal thickness, and t6 may be the minimum thickness of the second protective part 132.

[0478] For example, the first protective portion 131 includes 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 protective portion 132 is located between the second sub-part 12112 and the active material layer 20. Along the direction from the conductive portion 1211 to the transition portion 1212, the thickness of the first part gradually decreases, while the second part has a generally uniform thickness structure. This allows the thickness of the first protective portion 131 to match the thickness of the first sub-part 12111, making the surface of the conductive protective layer 13 facing away from the insulating substrate 11 nearly planar. Here, t5 is equal to the thickness of the second part.

[0479] By adopting the technical solution of this embodiment, the surface of the conductive protective layer 13 facing away from the insulating substrate 11 is close to a plane, which helps to reduce rolling damage and improve the current carrying capacity of the metal layer 12; in addition, it can also reduce the problem of winding bulging of the current collector 10.

[0480] In some embodiments, the conductive protective layer 13 further includes a third protective portion 133, which covers the surface of the transition portion 1212 facing 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.

[0481] In some examples, along the first direction, the conductive protective layer 13 can be divided into three parts: a part close to the conductive member 30 is the third protective part 133, a part away from the conductive member 30 is the second protective part 132, and the middle part is the first protective part 131. The thickness of the third protective part 133 is t7, where t7 ≤ t5 < t6. In addition, the thickness of the transition part 1212 is greater than or equal to the thickness of the first sub-part 12111, which can reduce the thickness difference between the current collector 10 at the first protective part 131 and the third protective part 133, and facilitate the surface of the conductive protective layer 13 facing away from the metal layer 12 to approach a plane.

[0482] For example, the second protective portion 132, the third protective portion 133, the transition portion 1212, and the second sub-portion 12112 are all of equal thickness, while the first sub-portion 12111 and the first protective portion 131 are of unequal thickness; the thickness of the first sub-portion 12111 and the thickness of the first protective portion 131 are adapted to each other so that the surface of the conductive protective layer 13 facing away from the insulating substrate 11 is close to a plane.

[0483] By adopting the technical solution of this embodiment, the provision of the third protective part 133 allows the conductive protective layer 13 to protrude from the active material layer 20, thereby better separating the active material layer 20 and the metal layer 12. In addition, the thickness of the third protective part 133 is not too large, which helps to reduce material waste and save the manufacturing cost of the battery cell 100.

[0484] In some embodiments, the metal layer 12 further includes at least one protrusion 122, and a transition portion 1212 is connected between the protrusion 122 and the conductive portion 1211; along a second direction, the sum of the dimensions of all the protrusions 122 is less than the dimension of the transition portion 1212, and the second direction is perpendicular to the first direction and the thickness direction of the current collector 10; the thickness of the protrusion 122 is greater than or equal to the thickness of the transition portion 1212.

[0485] For example, the thickness of the protrusion 122 may be equal to the thickness of the transition portion 1212, so that the protrusion 122 and the transition portion 1212 form a structure of equal thickness.

[0486] For example, the thickness of the protrusion 122 may also be greater than the thickness of the transition portion 1212, so that the protrusion 122 and the transition portion 1212 form a stepped structure.

[0487] By adopting the technical solution of this embodiment, the thickness of the protrusion 122 is relatively large, which can improve the current carrying capacity of the protrusion 122, which is beneficial to improving the current carrying capacity of the first electrode 1, reducing the heat generation of the battery cell 100, and improving the fast charging performance and reliability of the battery cell 100.

[0488] The battery cell 100 of this application will be described below with reference to some embodiments.

[0489] Example 1

[0490] In this embodiment, referring to Figures 3-12, the battery cell 100 includes an end cap 201, a housing 202 and an electrode assembly 101. The electrode assembly 101 is installed inside the housing 202. The end cap 201 covers the opening of the housing 202 to seal the housing 202. The end cap 201 is provided with an electrode lead-out portion 2011.

[0491] In this embodiment, the electrode assembly 101 includes a first electrode 1, a second electrode 2 and an insulating member 3 wound together. The insulating member 3 is located between the first electrode 1 and the second electrode 2. The first electrode 1 and the second electrode 2 have opposite polarities. The first electrode 1 can be a positive electrode and the second electrode 2 can be a negative electrode.

[0492] In this embodiment, the first electrode 1 includes a current collector 10, an active material layer 20, and a conductive component 30. The current collector 10 includes an insulating substrate 11, a metal layer 12, and a conductive protective layer 13. The metal layer 12 covers the two opposite surfaces of the insulating substrate 11 along the thickness direction. The conductive protective layer 13 covers the surface of the metal layer 12 facing away from the insulating substrate 11. The active material layer 20 covers the surface of the conductive protective layer 13 facing away from the insulating substrate 11.

[0493] In this embodiment, the metal layer 12 includes a main body 121 and at least one protrusion. The main body 121 includes a transition portion 1212 and a conductive portion 1211. The protrusion 122, the transition portion 1212 and the conductive portion 1211 are arranged along a first direction. The transition portion 1212 is connected between the conductive portion 1211 and the protrusion 122. The active material layer 20 covers the conductive portion 1211. The protrusion 122 and the transition portion 1212 are not covered by the active material layer 20. The first direction is perpendicular to the thickness direction of the current collector 10.

[0494] In this embodiment, conductive components 30 are welded to both metal layers 12. Each conductive component 30 includes a first connecting portion 31 and a second connecting portion 32 connected to each other. The first connecting portion 31 is welded to the metal layer 12 to form a first solder mark 51, and the second connecting portions 32 of the two conductive components 30 are welded to form a second solder mark 52.

[0495] In this embodiment, the first solder mark 51 includes a first solder mark portion 511 and a second solder mark portion 512, and the first connecting portion 31 includes a first connecting sub-portion 311 and at least one 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 welded to the transition portion 1212 to form the first solder mark portion 511, and the second connecting sub-portion 312 is welded to the protrusion 122 to form the second solder mark portion 512.

[0496] In this embodiment, there are multiple protrusions 122, which are arranged at intervals along a second direction, which is perpendicular to the first direction and the thickness direction of the current collector 10.

[0497] In this embodiment, the electrode assembly 101 includes a first insulating member 41, which protrudes from the edge of the first connector portion 311 away from the active material layer 20, and covers the first solder mark 51 and the second solder mark 52.

[0498] In this embodiment, the first insulating member 41 includes a first insulating portion 4121 and a plurality of second insulating portions 4122. The first insulating portion 4121 is continuously disposed along the second direction and covers the first connecting portion 311. The plurality of second insulating portions 4122 are connected to the side of the first insulating portion 4121 away from the active material layer 20. The plurality of second insulating portions 4122 are sequentially connected along the second direction to form a whole. The second insulating portions 4122 cover the second connecting portions 312 one by one. The portions of two adjacent first insulating portions 4121 and the areas of the first connecting portion 311 where the second connecting portion 312 is not extended form a blocking portion 4131. The blocking portions 4131 of two second insulating portions 4122 are attached to each other.

[0499] In this embodiment, the electrode assembly 101 further includes a second insulating member 42, which covers the surface of the transition portion 1212 facing away from the insulating substrate 11. The second insulating member 42 is located between the first connector portion 311 and the active material layer 20, and the first insulating member 41 covers the second insulating member 42.

[0500] Example 2

[0501] The difference between this embodiment and Embodiment 1 is that, as shown in FIG13, the electrode assembly 101 does not include the second insulating member 42, one side of the first insulating member 41 covers the first solder mark 51, and the other side of the first insulating member 41 covers the active material layer 20.

[0502] Example 3

[0503] The difference between this embodiment and Embodiment 1 is that, as shown in Figures 13, 14 and 15, the first insulating member 41 includes an insulating base layer 4111 and an adhesive layer 4112, with the adhesive layer 4112 bonded to the first electrode 1.

[0504] In some embodiments, referring to the figures, a battery device 1100 is provided, including the battery cell 100 of the above embodiments.

[0505] The battery device 1100 of this application embodiment adopts the above-mentioned battery cell 100, and the battery cell 100 has good reliability in use, so the battery device 1100 has good reliability in use.

[0506] In some embodiments, an electrical device is provided, including a battery device 1100 as described in the above embodiments.

[0507] The electrical device in this application embodiment uses the battery device 1100 described above. The battery device 1100 has good reliability, which helps to improve the reliability of the electrical device.

[0508] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0509] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, 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, comprising: a housing provided with an electrode lead-out portion; an electrode assembly at least partially accommodated in the housing, the electrode assembly comprising a first electrode tab and a first insulating member, the first electrode tab comprising a conductive member, a current collector and an active material layer, the current collector comprising 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, and at least part of the metal layer is located between the insulating base body and the active material layer; the metal layer comprises a main body portion, the main body portion comprises a transition portion and a conductive 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 conductive portion is covered with the active material layer, and the transition portion is not covered with the active material layer; the conductive member comprises a first connecting portion and at least one second connecting portion connected to each other, the first connecting portion is connected to the metal layer, the second connecting portion is electrically connected to the electrode lead-out portion, the first connecting portion comprises a first connecting sub-portion, and the first connecting sub-portion covers the surface of the transition portion away from the insulating base body; along the direction of the conductive portion pointing to the transition portion, the first insulating member protrudes from the edge of the first connecting sub-portion away from the active material layer.

2. The battery cell of claim 1, wherein: along the direction of the transition portion pointing to the conductive portion, the first insulating member protrudes from the edge of the first connecting sub-portion close to the active material layer.

3. The battery cell according to claim 1 or 2, characterized in that: along the first direction, the edge of the transition portion away from the conductive portion is flush with the edge of the first connecting sub-portion away from the active material layer.

4. The battery cell according to any one of claims 1 to 3, characterized in that: along a second direction, the size of the conductive portion is L1, the size of the transition portion is L2, and 0.8<=L2 / L1<=1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

5. The battery cell according to any one of claims 1 to 4, characterized in that: the first connecting portion is welded to the surface of the metal layer away from the insulating base body to form a first welding mark, and along the first direction, the first welding mark is located on the side of the active material layer close to the transition portion.

6. The battery cell of claim 5, wherein: the first insulating member covers at least part of the first welding mark.

7. The battery cell of claim 5 or 6, wherein: the first welding mark comprises a first welding mark portion, and the first connecting sub-portion is welded to the surface of the transition portion away from the insulating base body to form the first welding mark portion.

8. The battery cell of claim 7, wherein: along a second direction, the size of the transition portion is L2, the size of the first welding mark portion is L3, and 0.8<=L3 / L2<=1, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

9. The battery cell of claim 7 or 8, wherein: the first insulating member covers at least part of the first welding mark portion.

10. The battery cell of claim 9, wherein: along the direction of the transition portion pointing to the conductive portion, the first insulating member protrudes from the edge of the first welding mark portion close to the active material layer; and / or, along the direction of the conductive portion pointing to the transition portion, the first insulating member protrudes from the edge of the first welding mark portion away from the active material layer.

11. The battery cell according to any one of claims 7 to 10, characterized in that: along the first direction, the edge of the first welding mark portion away from the active material layer is flush with the edge of the first connecting sub-portion away from the active material layer.

12. The battery cell of any one of claims 7-11, wherein: In the second direction, opposite edges of the transition portion are flush with opposite edges of the first connecting sub-portion, and opposite edges of the first welding mark portion are flush with opposite edges of the first connecting sub-portion.

13. The battery cell of any one of claims 5-12, wherein: The metal layer further comprises at least one protruding portion, and the transition portion is connected between the protruding portion and the conductive portion. In the second direction, the sum of sizes of all the protruding portions is less than the size of the transition portion, and the second direction is perpendicular to the first direction and the thickness direction of the current collector. The first connecting portion comprises at least one second connecting sub-portion, the second connecting sub-portion is connected between the first connecting sub-portion and the second connecting portion, the second connecting sub-portion covers the surface of the protruding portion away from the insulating base, and the second connecting sub-portion and the protruding portion correspond one-to-one.

14. The battery cell of claim 13, wherein: The first welding mark comprises at least one second welding mark portion, and the second connecting sub-portion is welded with the corresponding protruding portion to form one second welding mark portion.

15. The battery cell of claim 14, wherein: The first insulating member covers at least part of the second welding mark portion.

16. The battery cell of claim 15, wherein: In the direction of the transition portion pointing to the conductive portion, the first insulating member protrudes from the edge of the second welding mark portion close to the active material layer; and / or, in the direction of the conductive portion pointing to the transition portion, the first insulating member protrudes from the edge of the second welding mark portion away from the active material layer.

17. The battery cell of any one of claims 13-16, wherein: In the direction of the transition portion pointing to the conductive portion, the first insulating member protrudes from the edge of the second connecting sub-portion close to the active material layer; and / or, in the direction of the conductive portion pointing to the transition portion, the first insulating member protrudes from the edge of the second connecting sub-portion away from the active material layer.

18. The battery cell of any one of claims 13-17, wherein: The first insulating member comprises a first insulating portion and at least one second insulating portion, the first insulating portion covers the first connecting sub-portion, and the second insulating portion covers the second connecting sub-portion, and the second insulating portion corresponds to the second connecting sub-portion one-to-one.

19. The battery cell of claim 18, wherein: In the second direction, at least one side of the first insulating portion protrudes from the corresponding side of the first connecting sub-portion.

20. The battery cell of claim 18 or 19, wherein: The number of the protruding portions is plural, the number of the second connecting sub-portions is plural, the plurality of protruding portions are arranged at intervals in the second direction, the plurality of second connecting sub-portions are arranged at intervals in the second direction, the plurality of protruding portions and the plurality of second connecting sub-portions are arranged one-to-one, the number of the second connecting portions is plural, the plurality of second connecting portions are arranged at intervals in the second direction, the second connecting sub-portion and the second connecting portion correspond one-to-one, and the plurality of second connecting sub-portions are connected to the edge of the first connecting sub-portion away from the active material layer; the first connecting sub-portion is arranged continuously in the second direction; the number of the second insulating portions is plural, the plurality of second insulating portions are arranged in the second direction, and the second insulating portion corresponds to the second connecting sub-portion one-to-one.

21. The battery cell of claim 20, wherein: Adjacent two second insulating portions are connected.

22. The battery cell of any one of claims 5-21, wherein: In the first direction, the first welding mark and the active material layer are arranged at intervals.

23. The battery cell of claim 22, wherein: In the first direction, the first welding mark is spaced apart from the active material layer by S1, where 0.3 mm ≤ S1 ≤ 5 mm, and optionally, 0.5 mm ≤ S1 ≤ 2.8 mm.

24. The battery cell of claim 22 or 23, wherein, The electrode assembly includes a second insulating member covering a surface of the metal layer facing away from the insulating substrate, and the entire second insulating member is located between the first welding mark and the active material layer.

25. The battery cell of claim 24, wherein: In the first direction, the first connecting sub-department is spaced apart from the active material layer.

26. The battery cell of claim 25, wherein: At least part of the second insulating member is located between the first connecting sub-department and the active material layer.

27. The battery cell of claim 26, wherein: The electrode assembly further includes a second tab having a polarity opposite to that of the first tab, the second tab including a main functional part arranged in the first direction and a tab part extending outwardly from a first end surface of the main functional part near an end of the transition part, and a projection of the first end surface is located within a projection of the second insulating member in the thickness direction of the current collector.

28. The battery cell of any one of claims 23-27, wherein: In the first direction, one side of the first insulating member covers the first connecting sub-department, and the other side of the first insulating member covers at least part of the second insulating member.

29. The battery cell of any one of claims 1-28, wherein: In the first direction, one side of the first insulating member covers the first connecting sub-department, and the other side of the first insulating member covers at least part of the active material layer.

30. The battery cell of claim 29, wherein: In the first direction, the size of the part of the first insulating member covering the active material layer is H, where 0.2 mm ≤ H ≤ 1.0 mm, and optionally, 0.3 mm ≤ H ≤ 0.8 mm.

31. The battery cell of any one of claims 1-30, wherein: The electrode assembly further includes a second tab having a polarity opposite to that of the first tab, the second tab including a main functional part arranged in the first direction and a tab part extending outwardly from a first end surface of the main functional part near an end of the transition part, and a projection of the first end surface is located within a projection of the first connecting sub-department in the direction of the conductive part toward the transition part.

32. The battery cell of any one of claims 1-31, wherein: The electrode assembly further includes a second tab having a polarity opposite to that of the first tab, the second tab including a main functional part arranged in the first direction and a tab part extending outwardly from a first end surface of the main functional part near an end of the transition part, and a projection of the first end surface is located within a projection of the first insulating member in the thickness direction of the current collector.

33. The battery cell of any one of claims 1-32, wherein: The number of the metal layers is two, the two metal layers cover opposite sides of the insulating substrate in the thickness direction of the current collector, and the number of the active material layers is two, the two active material layers respectively cover the conductive parts of the two metal layers. The number of the conductive members is two, the first connecting parts of the two conductive members are respectively connected to the two metal layers. The number of the first insulating members is two, and the two first insulating members respectively cover the first connecting sub-departments of the two conductive members.

34. The battery cell of claim 33, wherein: The first insulating member protrudes from a portion of the first connecting sub-portion to form a blocking portion in a direction pointing from the conductive portion to the transition portion, and the blocking portion is located at a side portion of the second connecting portion in a second direction, wherein the second direction is perpendicular to the first direction and a thickness direction of the current collector.

35. The battery cell of claim 34, wherein: The blocking portions of the two first insulating members are in abutment.

36. The battery cell of any one of claims 33-35, wherein: The second connecting portions of the two conductive members are welded and form a second welding mark.

37. The battery cell of claim 36, wherein: The first insulating member covers at least a portion of the second welding mark.

38. The battery cell of claim 37, wherein: In a direction pointing from the conductive portion to the transition portion, the first insulating member protrudes from the second welding mark away from an edge of the active material layer.

39. The battery cell of any one of claims 1-38, wherein: The current collector comprises a conductive protective layer, and at least a portion of the conductive protective layer is located between the active material layer and the conductive portion.

40. The battery cell of claim 39, wherein: In a direction pointing from the conductive portion to the transition portion, the conductive protective layer protrudes from an end portion of the active material layer close to the first connecting sub-portion.

41. The battery cell of claim 40, wherein: In a direction pointing from the conductive portion to the transition portion, the protruding length of the conductive protective layer protruding from the active material layer ranges from 0.3 mm to 0.8 mm.

42. The battery cell of any one of claims 39-41, wherein: The first connecting portion is welded to a surface of the metal layer away from the insulating base to form a first welding mark, and the conductive protective layer and the first welding mark are arranged in a spaced manner in the first direction.

43. The battery cell of any one of claims 1-42, wherein: The first insulating member is connected to the first pole piece.

44. The battery cell of claim 43, wherein: The first insulating member comprises an insulating base layer and an adhesive layer, and the adhesive layer is bonded between the insulating base layer and the first pole piece.

45. The battery cell of claim 44, wherein: The layer thickness of the insulating base layer ranges from 6 μm to 15 μm; and / or the layer thickness of the adhesive layer ranges from 0.5 μm to 3 μm.

46. The battery cell of any one of claims 1-45, wherein: In the first direction, the size of the first insulating member is W, wherein 3 mm ≤ W ≤ 9 mm, and optionally, 4.5 mm ≤ W ≤ 6.5 mm.

47. The battery cell of any one of claims 1-46, wherein: At least a portion of the conductive portion has a thickness smaller than that of the transition portion.

48. The battery cell of claim 47, wherein: The conductive portion comprises a first sub-portion and a second sub-portion, the first sub-portion is connected between the second sub-portion and the transition 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 that of the second sub-portion, and the thickness of the transition portion is greater than or equal to that of the first sub-portion.

49. The battery cell of claim 48, wherein: The current collector further comprises a conductive protective layer, the conductive protective layer comprises 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 smaller than that of the second protective portion.

50. The battery cell of claim 49, wherein: The conductive protective layer further comprises a third protective portion, the third protective portion covers a surface of the transition portion away from the insulating base, and the thickness of the third protective portion is smaller than or equal to that of the first protective portion.

51. The battery cell of any one of claims 1-50, wherein: The metal layer further comprises at least one protruding portion, and the transition portion is connected between the protruding portion and the conductive portion. In a second direction, the sum of the sizes of all the protruding portions is smaller than the size of the transition portion, and the second direction is perpendicular to the first direction and a thickness direction of the current collector. The thickness of the protrusion is greater than or equal to the thickness of the transition.

52. A battery device, comprising: A battery cell as claimed in any of claims 1 to 51.

53. An electrical device, comprising: A battery device as claimed in claim 52.

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