Battery cell, battery device, and electric device

Abstract

A battery cell (100), a battery device (1100), and an electrical device are disclosed. The battery cell (100) includes a housing (200) and an electrode assembly (101). The housing (200) has an electrode lead-out portion (2011). The electrode assembly (101) is housed within the housing (200) and includes a first electrode (1) and a first insulating member (4). 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), at least a portion of which is located between the insulating substrate (11) and the active material layer (20). The conductive member (30) is used to electrically connect the metal layer (12) and the electrode lead-out portion (2011). The conductive component (30) includes a first connecting portion (31), which is located on the side of the metal layer (12) away from the insulating substrate (11) and connected to the metal layer (12). A first insulating component (4) is attached to the first connecting portion (31). Along the direction of the first connecting portion (31) pointing towards the active material layer (20), the first insulating component (4) protrudes from the first end face (31a) of the first connecting portion (31) facing the active material layer (20).

Description

Battery cell, battery device and electric device

[0001] Cross-reference to Related Applications

[0002] This application claims priority to International Patent Application PCT / CN2024 / 106988 entitled "Battery cell, battery device and electric device" filed on July 23, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, and more particularly, to a battery cell, a battery device and an electric device. BACKGROUND

[0004] 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, electric tools, and the like.

[0005] In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology.

[0006] SUMMARY

[0007] The present application provides a battery cell, a battery device and an electric device, which can improve reliability.

[0008] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell and an electrode assembly. The shell is provided with an electrode lead-out portion. At least part of the electrode assembly is accommodated in the shell, and the electrode assembly comprises a first pole piece and a first insulating component. The first pole piece comprises a conductive member, a current collector and an active material layer. The current collector comprises an insulating base body and a metal layer, and 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 conductive member is used to electrically connect the metal layer and the electrode lead-out portion. The conductive member comprises a first connecting portion, the first connecting portion is located on the side of the metal layer away from the insulating base body and connected to the metal layer. The active material layer is arranged along a first direction with respect to the first connecting portion, and the first direction is perpendicular to the thickness direction of the current collector. At least part of the first insulating component is located on the side of the first connecting portion away from the metal layer and attached to the first connecting portion. In the direction of the first connecting portion pointing to the active material layer, the first insulating component protrudes from the first end surface of the first connecting portion facing the active material layer.

[0009] The current collector adopts a composite structure of an insulating base and a metal layer. Compared with a current collector made of pure metal, the metal layer has a smaller thickness, and when the current collector is accidentally punctured, the metal layer generates smaller burrs, and the burrs of the metal layer are less likely to puncture other components, thereby reducing the risk of short circuit and improving the use reliability of the battery cell. During normal use of the battery cell, the first insulating component can block the burrs at the first end face, reduce the possibility of the burrs at the first end face puncturing other components, reduce the risk of short circuit, and improve the reliability of the battery cell. For example, the electrode assembly further includes a second pole piece and a separator, and the first insulating component can block the burrs at the first end face, reduce the possibility of the burrs puncturing the separator and contacting the second pole piece, and further reduce the risk of short circuit.

[0010] In some embodiments, the first connecting portion and the active material layer are spaced apart along the first direction. Spacing the first connecting portion and the active material layer apart can reduce mutual influence therebetween and improve the use reliability of the battery cell.

[0011] In some embodiments, the first insulating component at least partially covers a region of the metal layer between the first connecting portion and the active material layer. The first insulating component can separate the region of the metal layer that is not covered by the first connecting portion and the active material layer from the second pole piece, thereby reducing the risk of short circuit and improving the reliability of the battery cell.

[0012] In some embodiments, a portion of the first insulating component is located between the first connecting portion and the active material layer along the first direction. The portion of the first insulating component located between the first connecting portion and the active material layer is attached to the metal layer. Attaching the first insulating component to the metal layer can increase the connection strength of the first insulating component to the first pole piece and reduce the risk of the first insulating component falling off. The portion of the first insulating component attached to the metal layer can shield the metal layer, improve the insulation, reduce the risk of the metal layer being in conduction with the second pole piece, and improve the reliability.

[0013] In some embodiments, the electrode assembly includes a second insulating component disposed on a surface of the metal layer facing away from the insulating base. At least a portion of the second insulating component is located between the first connecting portion and the active material layer along the first direction. The second insulating component can support the portion of the metal layer between the first connecting portion and the active material layer, reduce damage such as cracks or fractures of the portion of the metal layer during the manufacturing of the battery device, improve the electronic transmission capability of the portion of the metal layer, and improve the fast-charging performance and use reliability of the battery cell. In addition, the second insulating component can also separate the region of the metal layer that is not covered by the first connecting portion and the active material layer from the second pole piece, thereby reducing the risk of short circuit and improving the reliability of the battery cell.

[0014] In some embodiments, a portion of the first insulating member is located on the side of the second insulating member facing away from the metal layer and is connected to the second insulating member. Connecting the first insulating member to the second insulating member reduces the risk of the first insulating member detaching. The first and second insulating members can jointly cover the metal layer, thereby improving insulation performance, reducing the risk of conductivity between the metal layer and the second electrode, and improving reliability.

[0015] In some embodiments, the first insulating component is also connected to the active material layer to improve the connection strength between the first insulating component and the first electrode, reduce the risk of the first insulating component falling off the first electrode, and improve reliability.

[0016] In some embodiments, a first insulating member covers a portion of the active material layer. The first insulating member may cover the edge region of the active material layer to restrain the edge region of the active material layer and reduce the risk of the edge region of the active material layer collapsing or falling off due to stress concentration.

[0017] In some embodiments, the portion of the first insulating member covering the active material layer is configured to allow ions to pass through, thereby reducing the first insulating member's obstruction of ions and minimizing capacity loss of the first electrode.

[0018] In some embodiments, the portion of the first insulating member covering the active material layer has through holes. The through holes can serve as channels for ions to pass through.

[0019] In some embodiments, the first insulating component is configured to block the passage of ions. During charging, the first insulating component can block the passage of ions, reducing the number of ions that migrate to the negative electrode active material layer and lowering the risk of ion deposition.

[0020] In some embodiments, the active material layer includes a first active material portion and a second active material portion arranged along a first direction. The first active material portion is located on the side of the second active material portion facing the first connection portion. The thickness of the end of the first active material portion away from the second active material portion is less than the thickness of the second active material portion. Along the direction of the active material layer pointing towards the first connection portion, the thickness of the first active material portion decreases. A first insulating member covers at least a portion of the first active material portion.

[0021] In the forming process of the first electrode tab, the active material layer can be rolled to compact the active material layer; and the first active material part can reduce the rolling pressure on the edge of the active material layer and reduce the risk of cracking of the edge of the active material layer. The first active material part has a smaller thickness, and covering the first active material part with the first insulating part can improve the space utilization in the thickness direction of the current collector, reduce the pressure on the first insulating part when the electrode assembly expands, reduce stress concentration, reduce the risk of cracking of the active material layer by the first insulating part, and improve the cycle performance of the battery cell.

[0022] In some embodiments, the size of the portion of the active material layer covered by the first insulating part in the first direction is H, and 0.2mm≤H≤1mm. Limiting H to be greater than or equal to 0.2mm enables the first insulating part to protect the edge area of the active material layer and reduce the risk of material falling off the edge area of the active material layer. Limiting H to be less than or equal to 1mm can limit the area of the portion of the active material layer covered by the first insulating part and reduce the capacity loss. Limiting H to be 0.2mm-1mm can balance the use reliability and energy density of the battery cell.

[0023] In some embodiments, the metal layer includes a first metal part and a second metal part arranged and connected in the first direction, the first metal part is covered with the active material layer, and the second metal part is not covered with the active material layer. The first connecting part is welded to the second metal part and forms a first welding mark. Welding the second metal part and the first connecting part can simplify the manufacturing process of the first electrode tab and improve the current-carrying capacity between the metal layer and the first connecting part. By providing the second metal part not covered with the active material layer, the influence of welding on the active material layer can be reduced.

[0024] In some embodiments, the second metal part includes at least one protruding part, and the sum of the sizes of all the protruding parts in the second direction is less than the size of the first metal part, the second direction being perpendicular to the first direction and the thickness direction of the current collector. The first connecting part includes at least one first connecting sub-part, the first connecting sub-part being located on the side of the protruding part away from the insulating base, and the first connecting sub-part corresponding to the protruding part one-to-one. By providing the protruding part, the space and volume occupied by the first electrode tab can be reduced, and the energy density of the battery cell can be improved. By providing the first connecting sub-part, the current-carrying area between the first connecting part and the second metal part can be increased, and the current-carrying capacity can be improved.

[0025] In some embodiments, the first insulating part includes at least one first insulating sub-part, the first insulating sub-part covering the surface of the first connecting sub-part away from the protruding part, and the first insulating sub-part corresponding to the first connecting sub-part one-to-one. The first insulating sub-part can cover the first connecting sub-part to reduce the risk of conduction between the first connecting sub-part and the second electrode tab and improve the use reliability of the battery cell.

[0026] In some embodiments, the first insulating component further comprises a second insulating sub connected to the first insulating sub, and the second insulating sub is located on the side of the first insulating sub facing the active material layer in the first direction. By arranging the second insulating sub, the first insulating component can protrude from the first connecting sub in the direction in which the first connecting sub points to the active material layer, thereby reducing the risk of the first connecting sub being in contact with the second tab. In addition, the second insulating sub can also be used to cover burrs at the first end surface, so as to reduce the possibility of the burrs piercing the separator and being in contact with the second tab, thereby reducing the risk of short circuit.

[0027] In some embodiments, the first insulating component further comprises a third insulating sub connected to the first insulating sub, and the third insulating sub is arranged in the second direction with the first insulating sub. By arranging the third insulating sub, the first insulating component can protrude from the first connecting sub in the second direction, thereby covering the burrs at the end of the first connecting sub in the second direction, reducing the possibility of the burrs piercing the separator and being in contact with the second tab, thereby reducing the risk of short circuit and improving the reliability of the battery cell.

[0028] In some embodiments, the current collector comprises two metal layers arranged on opposite sides of the insulating base along the thickness direction of the current collector. The first tab comprises two active material layers and two conductive members, the two active material layers are arranged on the two metal layers respectively, and the first connecting parts of the two conductive members are connected to the second metal parts of the two metal layers respectively. The electrode assembly comprises two first insulating components attached to the two first connecting parts respectively. The two first insulating components can cover the burrs at the first end surfaces of the two first connecting parts respectively, thereby reducing the possibility of the burrs piercing the separator and being in contact with the second tab, and reducing the risk of short circuit.

[0029] In some embodiments, the third insulating subs of the two first insulating components are attached and / or connected. After the third insulating subs of the two first insulating components are attached, the metal debris at the two ends of the first connecting sub in the second direction can be covered, so that the metal debris is not easy to fall into the electrode assembly, and the risk of short circuit of the battery cell can be better reduced.

[0030] In some embodiments, the first insulating component further comprises a fourth insulating sub connected to the first insulating sub, and the fourth insulating sub is located on the side of the first insulating sub away from the active material layer in the first direction. By arranging the fourth insulating sub, the insulation effect can be improved.

[0031] In some embodiments, the first connecting sub is welded to the protruding part and forms a first welding part, the first welding part comprises the first welding part; the first insulating sub covers at least part of the first welding part. The first connecting sub and the protruding part are connected by welding, which is simple and convenient for the manufacture of the first pole piece; the first connecting sub and the protruding part can directly flow through the first welding part, which is conducive to improving the flow capacity between the first connecting sub and the protruding part; the first insulating sub can block the burrs, metal debris and other structures on the first welding part, thereby reducing the risk of these structures penetrating the separator and contacting the second pole piece, and improving the use reliability of the battery cell.

[0032] In some embodiments, in the first direction, neither end of the first welding part exceeds the first insulating sub, so as to reduce the exposed area of the first welding part and reduce the risk of the first welding part piercing the separator, thereby improving the use reliability of the battery cell.

[0033] In some embodiments, the number of protruding parts is multiple, and the multiple protruding parts are arranged at intervals along the second direction. The first connecting part comprises multiple first connecting subs, and the multiple first connecting subs are arranged at intervals along the second direction, and the multiple first connecting subs correspond to the multiple protruding parts one by one. By arranging multiple protruding parts and multiple first connecting subs, the flow area between the first connecting part and the second metal part can be increased, the flow capacity can be improved, and the fast charging performance of the battery cell can be improved.

[0034] In some embodiments, the first insulating part comprises multiple first insulating subs arranged along the second direction, the first insulating sub covers the surface of the first connecting sub away from the protruding part, and the first insulating sub is arranged corresponding to the first connecting sub. Multiple first insulating subs cover multiple first connecting subs respectively, so as to reduce the risk of conduction between the first connecting sub and the second pole piece, and improve the use reliability of the battery cell.

[0035] In some embodiments, the first insulating part further comprises a second insulating sub, and in the first direction, the second insulating sub is located on the side of the multiple first insulating subs facing the active material layer. The second insulating sub continuously extends along the second direction and is connected to the multiple first insulating subs. The continuous arrangement of the second insulating sub can increase the insulation area and reduce the risk of short circuit. The second insulating sub connects the multiple first insulating subs into a whole, thereby reducing the risk of the first insulating sub falling off from the first connecting sub and improving the insulation reliability.

[0036] In some embodiments, the first insulating component further comprises a plurality of second insulating subparts, the plurality of first insulating subparts and the plurality of second insulating subparts are arranged one-to-one corresponding, and the first insulating subpart is connected with the corresponding second insulating subpart. In the first direction, the second insulating subpart is located on the side of the first insulating subpart facing the active material layer. By arranging multiple second insulating subparts, the size of a single second insulating subpart can be reduced, space can be saved, and energy density can be improved.

[0037] In some embodiments, the first insulating component comprises a plurality of third insulating subparts arranged along the second direction, and each first insulating subpart is connected to two third insulating subparts at both ends along the second direction. The two third insulating subparts can cover the burrs at both ends of the first connecting subpart along the second direction, thereby reducing the possibility of the burrs piercing the separator and contacting the second pole piece, reducing the risk of short circuit, and improving the reliability of the battery cell.

[0038] In some embodiments, the plurality of first insulating subparts and the plurality of third insulating subparts are arranged alternately along the second direction, and two adjacent first insulating subparts are connected by a third insulating subpart. The plurality of third insulating subparts connects the plurality of first insulating subparts into a whole, which can not only increase the insulating area, but also reduce the risk of the first insulating subpart falling off from the first connecting subpart, thereby improving the insulating reliability. The first insulating component is arranged continuously as a whole, which can constrain the first connecting subpart, reduce the deformation of the first connecting subpart, reduce the risk of the first connecting subpart being inserted into the active material layer and the second pole piece, and reduce the risk of short circuit.

[0039] In some embodiments, along the second direction, two third insulating subparts are arranged at intervals between two adjacent first insulating subparts. The two third insulating subparts located between the two adjacent first insulating subparts are connected with the two first insulating subparts, respectively. The first insulating component forms a hollow region between the two third insulating subparts, thereby saving the weight and space occupied by the first insulating component and improving the energy density.

[0040] In some embodiments, the first insulating component further comprises a plurality of fourth insulating subparts, the plurality of first insulating subparts and the plurality of fourth insulating subparts are arranged one-to-one corresponding, and the first insulating subpart is connected with the corresponding fourth insulating subpart. In the first direction, the fourth insulating subpart is located on the side of the first insulating subpart away from the active material layer. By arranging multiple fourth insulating subparts, the insulating effect can be improved.

[0041] In some embodiments, each first connecting subpart has a second end face at one end facing the active material layer, and the second end faces of the plurality of first connecting subparts form a first end face. The first insulating component can block the burrs at each second end face, reduce the possibility of the burrs piercing the separator and contacting the second pole piece at the second end face, and thereby reduce the risk of short circuit.

[0042] In some embodiments, the second metal part further comprises a transition part connected between the first metal part and the protruding part. In the second direction, the size of the transition part is greater than the sum of the sizes of all the protruding parts. The transition part can increase the flow area and improve the flow capacity.

[0043] In some embodiments, the first connecting part comprises a second connecting sub-part located on the side of the transition part away from the insulating base in the thickness direction of the current collector, and the first connecting sub-part is connected to the end face of the second connecting sub-part away from the active material layer. In the first direction, the end face of the second connecting sub-part facing the active material layer is the first end face. During the cycle of the battery monomer, a part of the current can be transmitted between the transition part and the second connecting sub-part, thereby reducing the flow pressure between the protruding part and the first connecting sub-part, which is conducive to reducing the heat generation of the protruding part and improving the fast charging performance and use reliability of the battery monomer. The first insulating part can block the burrs at the first end face, reduce the possibility of the burrs piercing the separator and contacting the second pole piece, and further reduce the risk of short circuit.

[0044] In some embodiments, the first insulating part comprises a second insulating sub-part covering the second connecting sub-part, and in the direction of the second metal part pointing to the first metal part, the second insulating sub-part protrudes from the first end face. The second insulating sub-part can block the burrs at the first end face, reduce the possibility of the burrs piercing the separator and contacting the second pole piece, and further reduce the risk of short circuit.

[0045] In some embodiments, in the second direction, the second insulating sub-part protrudes from the second connecting sub-part. The second insulating sub-part can block the burrs at both ends of the second connecting sub-part in the second direction, reduce the possibility of the burrs piercing the separator and contacting the second pole piece, and further reduce the risk of short circuit.

[0046] In some embodiments, the first insulating part further comprises a first insulating sub-part and a third insulating sub-part connected to the second insulating sub-part; in the first direction, the first insulating sub-part and the third insulating sub-part are located on the side of the second insulating sub-part away from the active material layer. The first insulating sub-part covers the surface of the first connecting sub-part away from the protruding part. The first insulating sub-part and the third insulating sub-part are arranged and connected in the second direction. The third insulating sub-part can block the burrs on the end face of the second connecting sub-part away from the active material layer, or block the burrs on the end of the first connecting sub-part in the second direction, thereby reducing the possibility of the burrs piercing the separator and contacting the second pole piece, reducing the risk of short circuit, and improving the use reliability of the battery monomer.

[0047] In some embodiments, the second connecting sub portion is welded to the surface of the transition portion away from the insulating base and forms a second welding mark portion, and the first welding mark includes the second welding mark portion. The second insulating sub portion covers at least part of the second welding mark portion. The second connecting sub portion and the transition portion can directly pass current through the second welding mark portion, which is conducive to improving the current passing capacity between the second connecting sub portion and the transition portion and reducing the heat generation of the battery monomer. The second insulating sub portion can block structures such as burrs and metal debris on the second welding mark portion, reduce the risk of these structures penetrating the separator and contacting the second pole piece, and improve the use reliability of the battery monomer.

[0048] In some embodiments, in the first direction, neither end of the second welding mark portion exceeds the second insulating sub portion, so as to reduce the exposed area of the second welding mark portion and reduce the risk of the second welding mark portion piercing the separator, thereby improving the use reliability of the battery monomer.

[0049] In some embodiments, in the second direction, the size of the transition portion is L2, the size of the second welding mark portion is L3, and 0.8≤L3 / L2≤1. By setting L3 / L2 to be 0.8-1, the size of the transition portion in the second direction can be relatively large, which is conducive to improving the connection area between the first connecting portion and the transition portion, improving the current passing capacity at the connection between the first connecting portion and the transition portion, reducing the heat generation of the battery monomer, and improving the fast charging performance of the battery monomer.

[0050] In some embodiments, the end surface of the second connecting sub portion away from the active material layer is flush with the end surface of the transition portion away from the first metal portion, which can reduce the redundancy of the second connecting sub portion or the redundancy of the transition portion, save materials, improve the space utilization, and improve the energy density of the battery monomer.

[0051] In some embodiments, the number of protrusions is a plurality, and the plurality of protrusions are arranged at intervals in the second direction. The first connecting portion includes the second connecting sub portion and a plurality of first connecting sub portions, the plurality of first connecting sub portions are arranged at intervals in the second direction, and each first connecting sub portion is welded to each protrusion and forms a first welding mark portion. The second connecting sub portion is arranged continuously in the second direction, is welded to the transition portion, and forms a second welding mark portion. The first welding mark includes the second welding mark portion and the plurality of first welding mark portions. The continuous arrangement of the second connecting sub portion in the second direction can connect the plurality of first connecting sub portions into one whole, and the second connecting sub portion can provide good support to the first connecting sub portions, which can reduce the risk of the first connecting sub portions being inserted between the active material layer and the second pole piece when being bent, reduce the short circuit risk, and improve the use reliability of the battery monomer. In addition, in the second direction, the size of the second connecting sub portion is large, which is conducive to increasing the welding area between the second connecting sub portion and the transition portion, improving the current passing capacity at the connection between the first connecting portion and the transition portion, improving the current passing capacity of the first pole piece, and improving the fast charging performance and use reliability of the battery monomer.

[0052] In some embodiments, the protrusion includes a first protruding subpart and a second protruding subpart, the first protruding subpart being connected between the second protruding subpart and the first metal part. In the second direction, the size of the first protruding subpart is greater than the size of the second protruding subpart. The first connecting subpart includes a first connecting protrusion on the side of the first protruding subpart away from the insulating base and a second connecting protrusion on the side of the second protruding subpart away from the insulating base; in the second direction, the size of the first connecting protrusion is greater than the size of the second connecting protrusion. The first insulating part includes at least one first insulating subpart corresponding to the first connecting subpart. The first insulating subpart covers the first connecting protrusion and the second connecting protrusion. The first insulating subpart can cover the first connecting protrusion and the second connecting protrusion, reducing the risk of contact and conduction between the first connecting subpart and the second pole piece.

[0053] In some embodiments, the second metal part includes a transition part, in the second direction, both ends of the transition part are flush with both ends of the first metal part, and the second direction is perpendicular to the first direction and the thickness direction of the current collector. The first connecting part includes a second connecting subpart on the side of the transition part away from the insulating base, the second connecting subpart is welded to the surface of the transition part away from the insulating base and forms a second welding mark part, and the first welding mark includes the second welding mark part. The end surface of the second connecting subpart facing the active material layer is a first end surface. In the cycle process of the battery monomer, the current can be transmitted between the transition part and the second connecting subpart, thereby improving the overcurrent capacity and improving the fast charging performance and use reliability of the battery monomer. The first insulating part can block burrs at the first end surface, reduce the possibility of burrs piercing the separator and contacting the second pole piece, and thereby reduce the risk of short circuit.

[0054] In some embodiments, in the direction of the first metal part pointing to the second metal part, the first insulating part protrudes from the end surface of the second connecting subpart away from the active material layer. The first insulating part can block burrs at the end surface of the second connecting subpart away from the active material layer, reduce the possibility of burrs piercing the separator and contacting the second pole piece, and thereby reduce the risk of short circuit.

[0055] In some embodiments, in the second direction, both ends of the first insulating part protrude from the second connecting subpart. The first insulating part can block burrs at both ends of the second connecting subpart in the second direction, reduce the possibility of burrs piercing the separator and contacting the second pole piece, and thereby reduce the risk of short circuit.

[0056] In some embodiments, the electrode assembly further includes a second tab opposite to the first tab in polarity, the second tab including a main functional portion and a tab portion, the tab portion extending from an end surface of the main functional portion in the first direction. In a direction of the active material layer pointing to the first connecting portion, an end surface of the main functional portion facing the tab portion exceeds the first end surface. The first insulating member separates the first end surface from the main functional portion. The main functional portion can exceed the first end surface, so that the main functional portion can have a larger size in the first direction, thereby improving the capacity of the main functional portion. The first insulating member separates the first end surface from the main functional portion, thereby blocking burrs at the first end surface, reducing the possibility of burrs at the first end surface from lapping with the main functional portion, reducing the risk of short circuit, and improving the reliability of the battery cell.

[0057] In some embodiments, the electrode assembly further includes a second tab opposite to the first tab in polarity, the second tab including a main functional portion and a tab portion, the tab portion extending from an end surface of the main functional portion in the first direction. In a direction of the active material layer pointing to the first connecting portion, an end surface of the main functional portion facing the tab portion exceeds the first end surface. The first insulating member separates the first end surface from the main functional portion. The main functional portion can exceed the first end surface, so that the main functional portion can have a larger size in the first direction, thereby improving the capacity of the main functional portion. The first insulating member separates the first end surface from the main functional portion, thereby blocking burrs at the first end surface, reducing the possibility of burrs at the first end surface from lapping with the main functional portion, reducing the risk of short circuit, and improving the reliability of the battery cell.

[0058] In some embodiments, in a direction of the active material layer pointing to the first connecting portion, the first insulating member exceeds the end surface of the main functional portion facing the tab portion. The first insulating member can block burrs at the end surface of the main functional portion near the tab portion from piercing the separator and connecting with the first tab, thereby reducing the risk of short circuit between the first tab and the second tab, and improving the reliability of the battery cell.

[0059] In some embodiments, the current collector includes two metal layers arranged on opposite sides of the insulating substrate in the thickness direction of the current collector. The first tab includes two active material layers and two conductive members, the two active material layers being arranged on the two metal layers respectively, and the first connecting portions of the two conductive members being connected to the two metal layers respectively. The electrode assembly includes two first insulating members attached to the first connecting portions of the two conductive members respectively. The two conductive members can respectively lead out the current of the two metal layers, thereby improving the overcurrent capacity and improving the fast charging performance of the battery cell. The two first insulating members can respectively cover burrs at the first end surfaces of the two first connecting portions, thereby reducing the possibility of burrs piercing the separator and contacting the second tab, and reducing the risk of short circuit.

[0060] In some embodiments, a portion of the two first insulating members is attached and / or connected. This can reduce the risk of burrs extending from between the two first insulating members, and improve the reliability.

[0061] In some embodiments, the conductive member further comprises a second connecting portion connected to the first connecting portion, the second connecting portion being located on a side of the first connecting portion away from the active material layer in the first direction; the second connecting portion is electrically connected to the electrode lead-out portion. The second connecting portions of the two conductive members are welded and form a second welding mark. The second connecting portions of the two conductive members can connect the metal layers on the opposite sides of the insulating base, thereby breaking the insulation of the insulating base and effectively improving the conductivity of the first tab, improving the fast charging performance of the battery cell, reducing the heat generation of the battery cell, and improving the use reliability of the battery cell.

[0062] In some embodiments, the first insulating member covers at least part of the second welding mark. The first insulating member can block burrs, metal debris and the like on the second welding mark, reduce the risk of burrs, metal debris and the like piercing the separator and contacting the second tab, reduce the risk of short circuit, and improve the use reliability of the battery cell.

[0063] In some embodiments, in the direction of the active material layer pointing to the first connecting portion, the first insulating member protrudes from the edge of the second welding mark away from the active material layer. The first insulating member can completely cover the second welding mark to block burrs, metal debris and the like on the entire second welding mark, reduce the risk of burrs, metal debris and the like piercing the separator and contacting the second tab, reduce the risk of short circuit, and improve the use reliability of the battery cell.

[0064] In some embodiments, the metal layer comprises a first metal portion and a second metal portion arranged and connected in the first direction, the first metal portion is covered with the active material layer, and the second metal portion is not covered with the active material layer. The second metal portion comprises a transition portion and at least one protruding portion; the transition portion is connected between the first metal portion and the protruding portion. In the second direction, the size of the transition portion is greater than the sum of the sizes of all the protruding portions, and the second direction is perpendicular to the first direction and the thickness direction of the current collector. The first connecting portion is welded to the second metal portion and forms a first welding mark.

[0065] In some embodiments, in the second direction, the size of the first metal portion is L1, the size of the transition portion is L2, and 0.8≤L2 / L1≤1. By setting L2 / L1 to 0.8-1, the transition portion has a larger size in the second direction, which is conducive to increasing the connection area between the second connecting portion and the transition portion, improving the current carrying capacity of the connection between the second connecting portion and the transition portion, improving the current carrying capacity of the first tab, reducing the heat generation of the battery cell, and improving the fast charging performance of the battery cell.

[0066] In some embodiments, at least part of the first metal portion has a thickness smaller than that of the transition portion. The transition portion has a larger thickness and a better current carrying capacity, which is conducive to improving the current carrying capacity of the first tab, reducing the heat generation of the battery cell, and improving the fast charging performance and use reliability of the battery cell.

[0067] In some embodiments, the first metal part comprises 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 the 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. The first sub-part is connected between the second sub-part and the transition part, and the thickness of the first sub-part is greater than the thickness of the second sub-part, so that the overcurrent capacity of the first sub-part close to the transition part is greater than the overcurrent capacity of the second sub-part away from the transition part, which can reduce the current limitation, improve the overcurrent capacity of the first tab, reduce the heating of the battery monomer, and help to improve the use reliability of the battery monomer.

[0068] In some embodiments, the current collector further comprises a conductive protective layer, the conductive protective layer comprises 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; the thickness of the first protective part is less than the thickness of the second protective part. By setting the first protective part and the second protective part with different thicknesses, the surface of the conductive protective layer away from the insulating base can be close to a plane, which helps to reduce the roll damage and improve the overcurrent capacity of the metal layer; in addition, the winding bulging problem of the current collector can also be reduced.

[0069] In some embodiments, the conductive protective layer further comprises 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. The third protective part is provided, so that the conductive protective layer protrudes from the active material layer, and the active material layer and the metal layer can be better separated; in addition, the thickness of the third protective part is not too large, which helps to reduce the waste of materials and save the manufacturing cost of the battery monomer.

[0070] In some embodiments, the thickness of the protruding part is greater than or equal to the thickness of the transition part. The thickness of the protruding part is relatively thick, which can improve the overcurrent capacity of the protruding part, help to improve the overcurrent capacity of the first tab, reduce the heating of the battery monomer, and help to improve the fast charging performance and use reliability of the battery monomer.

[0071] In some embodiments, the conductive member further comprises at least one second connecting part connected to the first connecting part, the second connecting part is located on the side of the first connecting part away from the active material layer in the first direction; and the second connecting part is electrically connected with the electrode lead-out part. The second connecting part protrudes out of the metal layer, which can facilitate the connection between the second connecting part and the electrode lead-out part, and the processing and manufacturing are more convenient; at the same time, the risk of false welding and other problems can be reduced, which helps to improve the connection reliability of the metal layer and the conductive member, and also helps to improve the overcurrent capacity of the first tab and the fast charging performance of the battery monomer.

[0072] In some embodiments, the first connecting portion includes a plurality of first connecting sub-portions, the plurality of first connecting sub-portions are arranged at intervals along a second direction, the second direction is perpendicular to the first direction and the thickness direction of the current collector. Each first connecting sub-portion is connected to the metal layer. The number of the second connecting portions is plural, and each first connecting sub-portion is connected to each second connecting portion in one-to-one correspondence. By arranging a plurality of second connecting portions, the flow area can be increased, the flow capacity of the conductive member can be improved, the fast-charging performance of the battery monomer can be improved, the heat generation of the battery monomer can be reduced, and the use reliability of the battery monomer can be improved.

[0073] In some embodiments, the first connecting portion is welded to the surface of the metal layer away from the insulating base and forms a first welding mark. In the first direction, the distance between the first welding mark and the active material layer is S1, wherein 0.3mm≤S1≤5mm, and optionally, 0.5mm≤S1≤2.8mm.

[0074] The first welding mark can transmit current between the first connecting portion and the metal layer, thereby improving the flow capacity and reducing heat generation. By setting S1 to be greater than or equal to 0.3mm, the first welding mark can have a distance from the active material layer, reducing the risk of the conductive member being welded to the active material layer, reducing problems such as false welding, and improving the connection reliability of the first connecting portion and the metal layer. By setting S1 to be less than or equal to 5mm, the distance between the first welding mark and the active material layer is not too large, and under the condition that the size of the metal layer in the first direction is constant, the active material layer can cover a larger area, which is beneficial to improve the coverage area of the active material layer on the metal layer and improve the energy density of the battery monomer.

[0075] In some embodiments, the current collector further includes a conductive protective layer, at least part of the conductive protective layer is located between the active material layer and the metal layer. The conductive protective layer can separate the active material layer and the metal layer while protecting the metal layer, reducing the risk of cracks in the metal layer caused by rolling the active material layer, and improving the flow capacity of the metal layer.

[0076] In some embodiments, in the direction of the active material layer pointing to the first connecting portion, the conductive protective layer protrudes from the end face of the active material layer towards the first connecting portion. The conductive protective layer protrudes from the active material layer, and the conductive protective layer can completely separate the metal layer and the active material layer, and in addition, it can provide an extension space for the active material layer during rolling, which is beneficial to the conductive protective layer obtained subsequently to completely separate the metal layer and the active material layer.

[0077] In some embodiments, the protruding length of the conductive protective layer protruding from the active material layer towards the end face of the first connecting part in the direction pointing from the active material layer to the first connecting part ranges from 0.3 mm to 0.8 mm. The conductive protective layer can completely separate the active material layer and the metal layer, the protective ability of the conductive protective layer to the metal layer is better, the overcurrent capacity of the first pole piece is better, which is conducive to improving the fast charging performance and use reliability of the battery monomer; the protruding length of the conductive protective layer is not too large, which is conducive to saving the internal space of the battery monomer and improving the energy density of the battery monomer.

[0078] In some embodiments, the conductive protective layer and the first connecting part are spaced apart in the first direction, so as to reduce the possibility of the first connecting part overlapping with the conductive protective layer, reduce the interference of the conductive protective layer with the connection between the first connecting part and the metal layer, and improve the connection strength and overcurrent capacity between the first connecting part and the metal layer.

[0079] In some embodiments, the first insulating part includes an insulating base layer and an adhesive layer, and at least part of the adhesive layer is bonded between the insulating base layer and the first connecting part. The insulating base layer can have a relatively high structural strength, which can block burrs and is not easy to be pierced by burrs, thereby improving the insulation effect. Compared with the adhesive layer, the insulating base layer has high strength and small deformation during the bonding process of the first insulating part; the adhesive layer can stably fix the insulating base layer on the first pole piece, thereby reducing the risk of falling off of the first insulating part.

[0080] In some embodiments, 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. The insulating base layer has a certain thickness, which can block burrs and achieve insulation; the thickness of the insulating base layer is less than or equal to 15 μm, so that the thickness of the insulating base layer is not too large, which is conducive to reducing the volume occupied by the first insulating part and improving the energy density of the battery monomer. The adhesive layer has a certain thickness, so that the first insulating part can be stably bonded to the first pole piece, thereby improving the insulation reliability of the first insulating part; the thickness of the adhesive layer is less than or equal to 3 μm, so that the thickness of the adhesive layer is not too large, which is conducive to reducing the volume occupied by the first insulating part and improving the energy density of the battery monomer.

[0081] In some embodiments, the size of the first insulating part in the first direction is W, and 3 mm≤W≤9 mm, and optionally, 4.5 mm≤W≤6.5 mm. W is limited to be greater than or equal to 3 mm, so that the first insulating part has a certain size, which can better block the burrs at the first end face and improve the internal insulation effect of the battery monomer; W is limited to be less than or equal to 9 mm, which can limit the size of the first insulating part in the first direction, thereby reducing the volume and weight occupied by the first insulating part and improving the energy density of the battery monomer.

[0082] In a second aspect, the embodiments of the present application provide a battery device, which comprises the battery cell provided in any of the embodiments of the first aspect.

[0083] In a third aspect, the embodiments of the present application provide a power consuming device, which comprises the battery device provided in any of the embodiments of the second aspect, and the battery device is configured to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0084] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the drawings.

[0085] FIG. 1 is a structural schematic diagram of a vehicle provided in some embodiments of the present application;

[0086] FIG. 2 is a schematic diagram of a battery device provided in some embodiments of the present application;

[0087] FIG. 3 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0088] FIG. 4 is a schematic diagram of an electrode assembly of the battery cell provided in some embodiments of the present application;

[0089] FIG. 5 is a sectional view of the electrode assembly shown in FIG. 4 along line A-A;

[0090] FIG. 6 is an enlarged schematic diagram of the box in FIG. 5;

[0091] FIG. 7 is a schematic diagram of a first electrode tab and a first insulating component of the battery cell provided in some embodiments of the present application in an unfolded state;

[0092] FIG. 8 is a sectional view of FIG. 7 along line B-B;

[0093] FIG. 9 is a sectional view of FIG. 7 along line C-C;

[0094] FIG. 10 is a schematic diagram of the first electrode tab shown in FIG. 7;

[0095] FIG. 11 is an enlarged schematic diagram of the circle box in FIG. 10;

[0096] FIG. 12 is another schematic diagram of the first electrode tab shown in FIG. 10, in which a conductive member is shown;

[0097] FIG. 13 is an enlarged schematic diagram of the circle box in FIG. 12;

[0098] FIG. 14 is a schematic diagram of the first insulating component shown in FIG. 7;

[0099] Fig. 15 is an enlarged view of the circle in Fig. 14;

[0100] Fig. 16 is a schematic view of the conductive member shown in Fig. 10;

[0101] Fig. 17 is an enlarged view of the circle in Fig. 16;

[0102] Fig. 18 is a partial cross-sectional view of an electrode assembly of a battery cell according to some embodiments of the present application;

[0103] Fig. 19 is a schematic view of a first electrode tab, a first insulating member and a second insulating member of a battery cell according to some embodiments of the present application in an unfolded state;

[0104] Fig. 20 is a cross-sectional view of Fig. 19 taken along line D-D;

[0105] Fig. 21 is a schematic view of the first electrode tab and the second insulating member shown in Fig. 19;

[0106] Fig. 22 is an enlarged view of the circle in Fig. 21;

[0107] Fig. 23 is a schematic view of the first electrode tab shown in Fig. 21, wherein a conductive member is shown;

[0108] Fig. 24 is an enlarged view of the circle in Fig. 23;

[0109] Fig. 25 is a schematic view of the first insulating member shown in Fig. 19;

[0110] Fig. 26 is an enlarged view of the circle in Fig. 25;

[0111] Fig. 27 is a schematic view of a portion of the conductive member shown in Fig. 21;

[0112] Fig. 28 is a schematic view of a first electrode tab, a first insulating member and a second insulating member of a battery cell according to some embodiments of the present application in an unfolded state;

[0113] Fig. 29 is a schematic view of a partial structure of the first insulating member shown in Fig. 28;

[0114] Fig. 30 is a schematic view of a first electrode tab and a first insulating member of a battery cell according to some embodiments of the present application in an unfolded state;

[0115] Fig. 31 is a schematic view of the first electrode tab shown in Fig. 30;

[0116] Fig. 32 is another schematic view of the first electrode tab shown in Fig. 31, wherein a conductive member is omitted;

[0117] Fig. 33 is a partial cross-sectional view of an electrode assembly of a battery cell according to some embodiments of the present application;

[0118] FIG. 34 is a partial cross-sectional view of an electrode assembly of a battery cell according to some embodiments of the present application;

[0119] FIG. 35 is a schematic view of a first electrode tab of a battery cell according to some embodiments of the present application, in a flattened state, with the conductive member omitted;

[0120] FIG. 36 is an enlarged view of the circle in FIG. 35;

[0121] FIG. 37 is a schematic view of a first insulating member of a battery cell according to some embodiments of the present application;

[0122] FIG. 38 is a partial cross-sectional view of an electrode assembly of a battery cell according to some embodiments of the present application.

[0123] In the drawings, the drawings are not necessarily drawn to scale.

[0124] Reference signs are explained as follows:

[0125] 1000, vehicle; 1100, battery device; 1200, controller; 1300, motor;

[0126] 100, battery cell; 101, electrode assembly; 200, case; 201, end cap; 2011, electrode lead-out portion; 202, housing; 300, box; 301, first box portion; 302, second box portion;

[0127] 1, first electrode tab;

[0128] 10, current collector; 11, insulating base; 12, metal layer; 121, first metal portion; 1211, first sub-portion; 1212, second sub-portion; 122, second metal portion; 1221, protruding portion; 1221a, first protruding sub-portion; 1221b, second protruding sub-portion; 1222, transition portion; 13, conductive protective layer; 131, first protective portion; 132, second protective portion; 133, third protective portion;

[0129] 20, active material layer; 21, first active material portion; 22, second active material portion;

[0130] 30, conductive member; 31, first connecting portion; 311, first connecting sub-portion; 3111, first connecting protruding portion; 3112, second connecting protruding portion; 312, second connecting sub-portion; 31a, first end surface; 31b, second end surface; 32, second connecting portion;

[0131] 2, second electrode tab; 210, main functional portion; 220, tab portion;

[0132] 3, separator;

[0133] 4, first insulating member; 40, insulating sheet; 41, first insulator portion; 42, second insulator portion; 43, third insulator portion; 44, fourth insulator portion; 4a, insulating base layer; 4b, adhesive layer; 4c, through hole;

[0134] 51, first solder print; 511, first solder print portion; 5111, first solder print sub-portion; 5112, second solder print sub-portion; 512, second solder print portion; 52, second solder print;

[0135] 6, second insulating member;

[0136] X, second direction; Y, thickness direction; Z, first direction. DETAILED DESCRIPTION

[0137] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, and are not intended to limit the present application.

[0138] 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 the non-exclusive inclusion.

[0139] 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.

[0140] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents a "or" relationship between the front and rear associated objects.

[0141] 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.

[0142] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying 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 limiting the embodiments of the present application.

[0143] 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, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0144] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0145] "Multiple" appearing in the present application refers to two or more (including two).

[0146] At present, from the development of market situation, the application of battery device is more and more extensive. The battery device is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely applied to electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, and aerospace and other fields. With the continuous expansion of the application field of battery device, the market demand is also increasing.

[0147] The battery device generally refers to a single physical module including a plurality of battery monomers to provide higher voltage and capacity. The battery monomer can be the smallest unit constituting the battery device.

[0148] The battery monomer generally includes a housing and an electrode assembly accommodated in the housing, and the electrode assembly generally includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive electrode sheet and the negative electrode sheet.

[0149] The positive electrode sheet can include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The negative electrode sheet can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0150] The current collector (positive electrode current collector or negative electrode current collector) is usually made of metal material, such as metal aluminum foil and metal copper foil. However, the pure metal foil material is prone to produce metal burrs, and the burrs pierce the separator to cause internal short circuit, which causes a great risk of fire and explosion of the battery cell.

[0151] In order to reduce the risk of short circuit in the battery cell, a current collector is provided, which includes an insulating base and a metal layer covering the surface of the insulating base, and an active material layer covering the surface of the metal layer away from the insulating base. The thickness of the metal layer is usually set to be small, so that the burr generated by the metal layer during the process of foreign matter piercing the electrode sheet is small and is not easy to pierce the separator.

[0152] In order to lead the current of the metal layer, the electrode sheet is usually provided with a conductive member connected with the metal layer. However, the conductive member usually needs to be cut into a predetermined shape to meet the design requirements. However, burrs are prone to occur at the end surface of the conductive member after cutting, and the burrs are easy to pierce the separator, thereby causing the risk of short circuit and affecting the reliability of the battery cell.

[0153] In view of this, the embodiments of the present application provide a technical scheme, which covers the end surface of the conductive member facing the active material layer by setting an insulating part, thereby reducing the risk of burrs on the end surface piercing the separator, and facilitating to improve the use reliability of the battery cell.

[0154] 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.

[0155] The battery device disclosed in the embodiments of the present application can be used in a power utilization 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 utilization 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, etc. 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, etc., and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0156] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0157] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0158] As shown in FIG. 1, the vehicle 1000 is internally provided with a battery device 1100, which can be arranged at the bottom or 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.

[0159] The vehicle 1000 can further include a controller 1200 and a motor 1300, the controller 1200 is used to control the battery device 1100 to supply power to the motor 1300, for example, for the power demand of the vehicle 1000 during starting, navigation and driving.

[0160] 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, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0161] FIG. 2 is a schematic diagram of a battery device according to some embodiments of the present application.

[0162] In some embodiments, the battery device 1100 can include one or more battery cell assemblies for providing voltage and capacity.

[0163] The battery cell assembly can include a plurality of battery cells 100, which can be connected in series, in parallel or in a mixed connection through a busbar component. The mixed connection means that there are both series and parallel connections among the plurality of battery cells 100.

[0164] The battery cell 100 can be a secondary battery cell, which means that the battery cell can be activated by charging after discharging. By way of example, the battery cell can be the smallest unit constituting the battery device.

[0165] By way of example, the battery cell 100 can be 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.

[0166] By way of example, the battery cell 100 can be a prismatic battery cell, a soft-pack battery cell or other shaped battery cell, the prismatic battery cell includes a square can battery cell, a blade-shaped battery cell, a multi-prismatic battery cell, for example, a hexagonal prismatic battery cell, etc.

[0167] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells 100; as an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells 100 into one independent module. As an example, the battery module can be formed by bundling a plurality of battery cells 100 by a cable tie.

[0168] In some embodiments, the battery device 1100 can be a battery pack, which includes a box 300 and one or more battery cell assemblies accommodated in the box 300. As an example, the battery cell assembly can be a battery module, which can be accommodated in the box 300 by fixing the battery module in the box 300. As an example, the battery cell assembly can also be accommodated in the box 300 by directly fixing a plurality of battery cells 100 in the box 300.

[0169] In some embodiments, the box 300 for accommodating the battery cells 100 can be of various structures.

[0170] In some embodiments, the box 300 can include a first box part 301 and a second box part 302. The first box part 301 and the second box part 302 are buckled so that a closed space is formed inside the box 300 to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first box part 301 can be a top cover or a bottom plate.

[0171] In some embodiments, the box 300 can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are connected with the frame, so that a closed space is formed inside the box 300 to accommodate the battery cell assembly. As an example, the frame can include a plurality of side beams.

[0172] In some embodiments, the box 300 can be part of the chassis structure of the vehicle 1000. For example, part of the box 300 can be at least part of the floor of the vehicle 1000, or part of the box 300 can be at least part of the cross beam and the longitudinal beam of the vehicle 1000.

[0173] In some embodiments, the battery device 1100 can be an energy storage device.

[0174] The energy storage device can be used in energy storage power stations, wind power systems, solar power systems, mobile power systems, or temporary power supply systems, etc. The energy storage device can store electrical energy as needed and output electrical energy at appropriate times. For example, the energy storage device can store electrical energy during the off-peak period of electricity consumption, and provide electrical energy for related users or electrical devices during the peak period of electricity consumption.

[0175] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0176] FIG. 3 is an exploded schematic view of a battery cell according to some embodiments of the present application.

[0177] Referring to FIG. 3, in some embodiments, the battery cell 100 includes a housing 200 and an electrode assembly 101 contained in the housing 200.

[0178] In some embodiments, the housing 200 can be a steel shell, an aluminum shell, a plastic shell (e.g., polypropylene), a composite metal shell (e.g., a copper-aluminum composite shell 200), an aluminum-plastic film, or the like.

[0179] In some embodiments, the housing 200 can be a sealed structure or a non-sealed structure. As an example, when the housing 200 is a non-sealed structure, the housing 200 serves to protect the electrode assembly 101, and a sealing bag is further included between the housing 200 and the electrode assembly 101, which is used to encapsulate the electrode assembly 101 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the housing 200 is a sealed structure, it is used to encapsulate the electrode assembly 101 and the electrolyte, and the like.

[0180] In some embodiments, the housing 200 includes a shell 202 having an opening and an end cap 201 coupled to the shell 202 and covering the opening.

[0181] The shell 202 is a component used to cooperate with the end cap 201 to form an internal cavity of the battery cell 100, and the internal cavity formed can be used to contain the electrode assembly 101, the electrolyte, and other components.

[0182] The shell 202 and the end cap 201 can be independent components. As an example, an opening can be provided on the shell 202, and the end cap 201 is used to cover the opening to form the internal cavity of the battery cell 100.

[0183] The shell 202 can have various shapes and sizes, such as a cuboid shape, a cylindrical shape, a hexagonal prism shape, and the like. Specifically, the shape of the shell 202 can be determined according to the specific shape and size of the electrode assembly 101. The shell 202 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, aluminum-plastic film, steel-plastic film, and the like.

[0184] The shape of the end cap 201 can be adapted to the shape of the shell 202 to cooperate with the shell 202. The material of the end cap 201 can be the same as or different from the material of the shell 202. Optionally, the end cap 201 can be made of a material having a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like), so that the end cap 201 is not easily deformed when subjected to extrusion and impact, and the battery cell 100 can have higher structural strength and improved reliability.

[0185] The end cover 201 is connected to the shell 202 by welding, bonding, clamping or other means.

[0186] The shell 202 can be open at one end or both ends. In some examples, the shell 202 can be a structure open at one side, and the end cover 201 is provided as one and covers the shell 202. In other examples, the shell 202 can also be a structure open at both sides, and the end cover 201 is provided as two, and the two end covers 201 cover the two openings of the shell 202 respectively.

[0187] The electrode assembly 101 is a component in which an electrochemical reaction occurs in the battery cell 100. One or more electrode assemblies 101 can be contained in the shell 202.

[0188] The electrode assembly 101 includes a first electrode plate, a second electrode plate, and a separator, the first electrode plate and the second electrode plate being opposite in polarity, and the separator separating the first electrode plate and the second electrode plate.

[0189] One of the first electrode plate and the second electrode plate is a positive electrode plate, and the other is a negative electrode plate. At least part of the separator is located between the positive electrode plate and the negative electrode plate. During charging and discharging of the battery cell 100, active ions (e.g. lithium ions) are embedded and extracted between the positive electrode plate and the negative electrode plate. The separator is arranged between the positive electrode plate and the negative electrode plate, which can prevent the positive and negative electrodes from short-circuiting, while allowing the active ions to pass through.

[0190] In some embodiments, the battery cell 100 includes an electrode lead-out portion 2011. As an example, the number of electrode lead-out portions 2011 is two, and the two electrode lead-out portions 2011 are electrically connected to the positive electrode plate and the negative electrode plate respectively, for outputting or inputting the electrical energy of the battery cell 100.

[0191] As an example, at least one electrode lead-out portion 2011 is a positive electrode lead-out portion, and at least one electrode lead-out portion 2011 is a negative electrode lead-out portion. The positive electrode lead-out portion is connected to the positive electrode plate, and the negative electrode lead-out portion is connected to the positive electrode plate.

[0192] The positive electrode lead-out portion and the negative electrode lead-out portion are used to be electrically connected to an external circuit to achieve charging or discharging of the battery cell 100.

[0193] In some embodiments, the positive electrode lead-out portion includes a positive electrode terminal. At least part of the positive electrode terminal is exposed to the outside of the battery cell 100 to facilitate connection with a busbar component.

[0194] As an example, the positive electrode terminal can be a separately formed component which is mounted to the shell 202 or the end cover 201. Alternatively, the positive electrode terminal can also be part of the shell 202 or part of the end cover 201.

[0195] In some examples, the positive terminal is directly connected to the positive tab; in other examples, the positive lead further includes other conductive structures, such as a positive adapter tab, connecting the positive terminal and the positive tab.

[0196] In some embodiments, the positive terminal is connected to the end cap 201 by welding, riveting, clamping, or other means.

[0197] In some embodiments, the negative lead includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell 100 to facilitate connection with a bus member.

[0198] As an example, the negative terminal can be a separately formed component that is mounted to the housing 202 or the end cap 201. Alternatively, the negative terminal can also be part of the housing 202 or part of the end cap 201.

[0199] In some examples, the negative terminal is directly connected to the negative tab; in other examples, the negative lead further includes other conductive structures, such as a negative adapter tab, connecting the negative terminal and the negative tab.

[0200] In some embodiments, the negative terminal is connected to the end cap 201 by welding, riveting, clamping, or other means.

[0201] In some embodiments, the battery cell 100 further includes an electrolyte contained within the housing 200. The electrolyte functions to conduct ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid.

[0202] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0203] 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 difluorobisoxalate borate, lithium bisoxalate borate, lithium difluorobisoxalate phosphate, and lithium tetrafluorobisoxalate phosphate.

[0204] 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, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0205] The solvent can also be selected from ether solvents. The ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0206] 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.

[0207] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0208] 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.

[0209] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorous sulfur, argyrodite), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0210] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0211] FIG. 4 is a schematic view of an electrode assembly of a battery cell according to some embodiments of the present application.

[0212] Referring to FIG. 4, the electrode assembly 101 includes first and second polar plates 1 and 2 having opposite polarities. 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.

[0213] 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.

[0214] As an example, the positive current collector has two opposite surfaces in a thickness direction thereof, and the positive active material layer is disposed on either one or both of the two opposite surfaces of the positive current collector.

[0215] 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, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0216] As an example, the positive electrode active material layer includes a positive electrode active material, which 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 a positive electrode active material layer of a battery device. 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 LiFePO4 (may also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, 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 LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (may also be referred to as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (may also be referred to as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (may also be referred to as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (may also be referred to as NCM622), LiNi 0.8 Co 0.1 Mn 0.1 O2 (may also be referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2), and a modified compound thereof, etc.

[0217] In some embodiments, the negative electrode sheet can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0218] 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.).

[0219] 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 a battery device. These negative electrode active materials can be used alone only one or two or more can be used in combination.

[0220] In some embodiments, the positive electrode current collector is a composite current collector and the negative electrode current collector is a copper foil; in other embodiments, the positive electrode current collector is an aluminum foil and the negative electrode current collector is a composite current collector; in yet other embodiments, both the positive electrode current collector and the negative electrode current collector are composite current collectors.

[0221] In some embodiments, the electrode assembly 101 further includes a separator 3 for separating the first electrode sheet 1 and the second electrode sheet 2. The separator 3 can reduce the risk of positive and negative short circuits while allowing active ions to pass through.

[0222] In some embodiments, the separator 3 includes a separator film. The separator film of the present application can employ any known porous structure separator film having good chemical stability and mechanical stability.

[0223] 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.

[0224] 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.

[0225] In some embodiments, the electrode assembly 101 has a jelly-roll structure. As an example, the first electrode sheet 1 and the second electrode sheet 2 each have a strip shape, and the first electrode sheet 1, the separator 3, and the second electrode sheet 2 are wound to have a jelly-roll structure.

[0226] In some embodiments, the electrode assembly 101 has a stack structure.

[0227] As an example, a plurality of first electrode sheets 1 and a plurality of second electrode sheets 2 can be alternately stacked.

[0228] As an example, a plurality of first electrode sheets 1 can be provided, and the second electrode sheet 2 is folded to have a plurality of folded sections stacked one on another, and one first electrode sheet 1 is interposed between adjacent folded sections.

[0229] As an example, a plurality of first electrode sheets 1 and a plurality of second electrode sheets 2 can be alternately stacked.

[0230] As an example, a plurality of separators 3 can be provided, and each of the separators 3 is interposed between any adjacent first electrode sheet 1 or second electrode sheet 2.

[0231] As an example, the separators 3 can be continuously provided and interposed between any adjacent first electrode sheet 1 or second electrode sheet 2 by being folded or wound.

[0232] In some embodiments, the electrode assembly 101 can have a cylindrical shape, a flat shape, or a polygonal shape.

[0233] FIG. 5 is a sectional view of the electrode assembly shown in FIG. 4 taken along line A-A; FIG. 6 is an enlarged view of the boxed portion of FIG. 5; FIG. 7 is a schematic view of a first tab and a first insulating member of a battery cell in an unfolded state according to some embodiments of the present application; FIG. 8 is a sectional view of FIG. 7 taken along line B-B; FIG. 9 is a sectional view of FIG. 7 taken along line C-C; FIG. 10 is a schematic view of the first tab shown in FIG. 7; FIG. 11 is an enlarged view of the boxed portion of FIG. 10; FIG. 12 is another schematic view of the first tab shown in FIG. 10, in which a conductive member is shown; FIG. 13 is an enlarged view of the boxed portion of FIG. 12; FIG. 14 is a schematic view of the first insulating member shown in FIG. 7; FIG. 15 is an enlarged view of the boxed portion of FIG. 14; FIG. 16 is a schematic view of the conductive member shown in FIG. 10; and FIG. 17 is an enlarged view of the boxed portion of FIG. 16.

[0234] Referring to FIGS. 3 to 17, according to some embodiments of the present application, a 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 accommodated in the housing 200. The electrode assembly 101 includes a first tab 1 and a first insulating member 4. The first tab 1 includes a conductive member 30, a current collector 10, and an active material layer 20. The current collector 10 includes an insulating base 11 and a metal layer 12. The insulating base 11, the metal layer 12, and the active material layer 20 are stacked in a thickness direction Y of the current collector. At least a portion of the metal layer 12 is located between the insulating base 11 and the active material layer 20. The conductive member 30 is configured to electrically connect the metal layer 12 and the electrode lead-out portion 2011. The conductive member 30 includes a first connecting portion 31. The first connecting portion 31 is located on a side of the metal layer 12 facing away from the insulating base 11 and is connected to the metal layer 12. The active material layer 20 is disposed in a first direction Z with respect to the first connecting portion 31. The first direction Z is perpendicular to the thickness direction Y of the current collector. At least a portion of the first insulating member 4 is located on a side of the first connecting portion 31 facing away from the metal layer 12 and is attached to the first connecting portion 31. In a direction of the first connecting portion 31 pointing toward the active material layer 20, the first insulating member 4 protrudes from a first end face 31a of the first connecting portion 31 facing the active material layer 20.

[0235] In some examples, a portion of the electrode assembly 101 is located inside the housing 200, and another portion is located outside the housing 200. Alternatively, the entire electrode assembly 101 is located inside the housing 200.

[0236] The first tab 1 can be a positive tab or a negative tab. In some examples, the first tab 1 is a positive tab, the current collector 10 is a positive current collector, the positive current collector has a composite current collector structure, and the active material layer 20 is a positive active material layer. In other examples, the first tab 1 is a negative tab, the current collector 10 is a negative current collector, the negative current collector has a composite current collector structure, and the active material layer 20 is a negative active material layer.

[0237] The conductive member 30 can refer to a component for connecting the electrode lead-out portion 2011 and the current collector 10. As an example, the material of the conductive member 30 can be the same as the material of the metal layer 12. As an example, the conductive member 30 can adopt a copper foil or an aluminum foil to facilitate connection with the electrode lead-out portion 2011.

[0238] The electrode lead-out portion 2011 can be directly connected with the conductive member 30; for example, the electrode lead-out portion 2011 is directly welded to the conductive member 30. Alternatively, the electrode lead-out portion 2011 can be connected with the conductive member 30 through a conductive piece (for example, a jumper, etc.), for example, one end of the conductive piece is welded to the conductive member 30, and the other end of the conductive piece is welded to the electrode lead-out portion 2011.

[0239] The current collector 10 includes the metal layer 12 and the insulating base body 11. The current collector 10 is a multilayer structure. The insulating base body 11 can refer to a component of the current collector 10 made of an insulating material (for example, the above-mentioned polymer base material). The metal layer 12 can refer to a component of the current collector 10 made of a metal material.

[0240] The surface of the insulating base body 11 is covered with the metal layer 12. The surface of the metal layer 12 away from the insulating base body 11 is covered with the active material layer 20. The insulating base body 11, the metal layer 12, and the active material layer 20 are stacked. The stacking direction of the insulating base body 11, the metal layer 12, and the active material layer 20 can be the thickness direction Y of the current collector (see the Y direction in FIG. 8).

[0241] The active material layer 20 can be directly covered on the surface of the metal layer 12, or other substances can be covered on the surface of the metal layer 12 before the active material layer 20 is covered.

[0242] In some examples, one surface of the insulating base body 11 is covered with the metal layer 12. In other examples, both surfaces of the insulating base body 11 are covered with the metal layer 12. Among the two metal layers 12, at least one metal layer 12 is covered with the active material layer 20 away from the surface of the insulating base body.

[0243] The first direction Z can refer to a direction perpendicular to the thickness direction Y of the current collector. The second direction X can refer to a direction perpendicular to both the thickness direction Y and the first direction Z of the current collector.

[0244] In some examples, the electrode assembly 101 is in a wound structure. When the first electrode sheet 1 is in an unfolded state, the first direction Z can refer to the width direction of the first electrode sheet 1. The second direction X can refer to the length direction of the first electrode sheet 1. When the first electrode sheet 1 is in a wound state, the second direction X can also refer to the winding direction of the first electrode sheet 1.

[0245] In other examples, the electrode assembly 101 is a stacked structure, one of the first direction Z and the second direction X is a width direction of the first tab 1, and the other is a length direction of the first tab 1.

[0246] As an example, the active material layer 20 can cover a portion of the metal layer 12. The conductive member 30 can be connected to a portion of the metal layer 12 that is not covered by the active material layer 20.

[0247] The first connecting portion 31 can be a portion of the conductive member 30 that overlaps the metal layer 12 in the thickness direction Y. The first connecting portion 31 can be connected to the metal layer 12 by welding, adhesion, or other means to achieve electrical connection between the first connecting portion 31 and the metal layer 12.

[0248] In the first direction Z, the first end surface 31a of the first connecting portion 31 can be directly against the active material layer 20, or can be spaced apart from the active material layer 20.

[0249] The first connecting portion 31 can be a single whole that is continuously provided; correspondingly, the first end surface 31a is continuously provided. Alternatively, the first connecting portion 31 can also include a plurality of separately provided portions; correspondingly, the first end surface 31a can also include a plurality of separately provided surfaces.

[0250] The first insulating member 4 can refer to a member capable of insulation. The first insulating member 4 can refer to an integrated structure, or can be a member that is separately formed in multiple parts and assembled together.

[0251] The first insulating member 4 can be, but is not limited to, an insulating coating, an insulating adhesive (e.g., hot melt adhesive, etc.), or an insulating adhesive tape.

[0252] The first insulating member 4 can be one or a plurality.

[0253] The first insulating member 4 can be attached only to the first connecting portion 31, or can be attached to other portions of the first tab 1 at the same time. As an example, the first insulating member 4 can also be attached to the active material layer 20, the metal layer 12, or other portions of the first tab 1.

[0254] As an example, “attached” can refer to being attached and connected. For example, the first insulating member 4 is attached to the first connecting portion 31 by adhesion or coating.

[0255] The first insulating member 4 can have a structure that allows ions to pass through. For example, the first insulating member 4 can have a microporous structure. Alternatively, the first insulating member 4 can also have a structure that blocks the passage of ions.

[0256] As an example, the direction in which the first connecting portion 31 points toward the active material layer 20 can be parallel to the first direction Z.

[0257] In a direction in which the active material layer 20 points to the first connecting portion 31, the first insulating member 4 can protrude from an end surface of the first connecting portion 31 facing away from the active material layer 20, or can not protrude from the end surface of the first connecting portion 31 facing away from the active material layer 20.

[0258] In the thickness direction Y of the current collector, the first insulating member 4 covers at least part of the first end surface 31a. In the thickness direction Y of the current collector, the first insulating member 4 can completely cover the first end surface 31a, or can cover only part of the first end surface 31a.

[0259] In the thickness direction Y of the current collector, a projection of the first end surface 31a at least partially overlaps a projection of the first insulating member 4.

[0260] In the embodiments of the present application, the current collector 10 adopts a composite structure of the insulating base body 11 and the metal layer 12, the thickness of the metal layer 12 is small relative to the pure metal current collector 10, the burr generated by the metal layer 12 is small when the current collector 10 is accidentally punctured (for example, a nail test), the burr of the metal layer 12 is not easy to pierce other components, thereby reducing the risk of short circuit, and being conducive to improving the use reliability of the battery monomer 100. During the normal use of the battery monomer 100, the first insulating member 4 can block the burr at the first end surface 31a, reduce the possibility of the burr at the first end surface 31a piercing other components, reduce the risk of short circuit, and improve the reliability of the battery monomer 100. For example, the first insulating member 4 can block the burr at the first end surface 31a, reduce the possibility of the burr piercing the separator 3 and contacting the second pole piece 2, and thereby reduce the risk of short circuit.

[0261] In some embodiments, the first insulating member 4 completely covers the first end surface 31a.

[0262] In some embodiments, in the first direction Z, the first connecting portion 31 and the active material layer 20 are spaced apart.

[0263] The first connecting portion 31 and the active material layer 20 are not in direct contact, but there is a certain gap, so that the first connecting portion 31 does not contact the active material layer 20. Other structures can be arranged in this gap, or no other structures can be arranged.

[0264] The first connecting part 31 is spaced apart from the active material layer 20, which can reduce the mutual influence between the two and improve the use reliability of the battery monomer 100. For example, the first connecting part 31 is spaced apart from the active material layer 20, which can reduce the risk of interference between the first connecting part 31 and the active material layer 20 due to assembly errors. When the conductive member 30 is connected to other components (such as the electrode lead-out part 2011), the stress conducted to the active material layer 20 through the first connecting part 31 can be reduced, and the risk of active material falling off the active material layer 20 can be reduced.

[0265] In some embodiments, the battery monomer 100 is a lithium ion battery monomer. The first connecting part 31 is not in contact with the active material layer 20, which can reduce the risk of lithium precipitation and other risks, and is conducive to improving the use reliability of the battery monomer 100.

[0266] In some embodiments, the first insulating component 4 at least partially covers the region of the metal layer 12 between the first connecting part 31 and the active material layer 20.

[0267] The region of the metal layer 12 between the first connecting part 31 and the active material layer 20 can be referred to as an intermediate region. The first insulating component 4 can completely cover the intermediate region, or only cover a part of the intermediate region.

[0268] The part of the first insulating component 4 covering the intermediate region can be attached to the intermediate region, or spaced apart from the intermediate region.

[0269] The first insulating component 4 can separate the region of the metal layer 12 not covered by the first connecting part 31 and the active material layer 20 from the second pole piece 2, thereby reducing the risk of short circuit and improving the reliability of the battery monomer 100.

[0270] In some embodiments, the first insulating component 4 completely covers the region of the metal layer 12 between the first connecting part 31 and the active material layer 20.

[0271] In some embodiments, along the first direction Z, a part of the first insulating component 4 is located between the first connecting part 31 and the active material layer 20.

[0272] In some embodiments, the part of the first insulating component 4 between the first connecting part 31 and the active material layer 20 is attached to the metal layer 12.

[0273] Attaching the first insulating component 4 to the metal layer 12 can increase the connection strength of the first insulating component 4 and the first pole piece 1, and reduce the risk of the first insulating component 4 falling off. The part of the first insulating component 4 attached to the metal layer 12 can shield the metal layer 12, improve the insulation, reduce the risk of the metal layer 12 being in conduction with the second pole piece 2, and improve the reliability.

[0274] In some embodiments, the first insulating member 4 is also connected to the active material layer 20.

[0275] In some examples, the first insulating member 4 can be connected to an end surface of the active material layer 20 facing the first connecting portion 31; alternatively, the first insulating member 4 can also be connected to a surface of the active material layer 20 facing away from the metal layer 12 to cover a portion of the active material layer 20.

[0276] The embodiments of the present application can further improve the connection strength of the first insulating member 4 and the first pole piece 1, reduce the risk of the first insulating member 4 falling off from the first pole piece 1, and improve the reliability.

[0277] In some embodiments, the first insulating member 4 covers a portion of the active material layer 20. The first insulating member 4 can cover the edge region of the active material layer 20 to bind the edge region of the active material layer 20, thereby reducing the risk of the edge region of the active material layer 20 collapsing or falling off due to stress concentration.

[0278] As an example, the portion of the first insulating member 4 covering the active material layer 20 can be connected to the active material layer 20, or can only be attached to the active material layer 20 without being fixed to the active material layer 20.

[0279] In some embodiments, the first insulating member 4 is configured to block the passage of ions.

[0280] In some examples, the first pole piece 1 is a positive pole piece. Due to assembly errors, the edge region of the active material layer 20 towards the first connecting portion 31 can exceed the negative active material layer of the negative pole piece, causing the risk of ion precipitation in the negative active material layer; the first insulating member 4 can block the passage of ions, which can reduce the ions moving to the negative active material layer during the charging process, thereby reducing the risk of ion precipitation.

[0281] In other examples, the first pole piece 1 is a negative pole piece. Due to assembly errors, the positive active material layer can exceed the edge region of the active material layer 20 towards the first connecting portion 31, causing the risk of ion precipitation in the active material layer 20; the first insulating member 4 can block the passage of ions, which can reduce the ions moving to the active material layer 20 during the charging process, thereby reducing the risk of ion precipitation.

[0282] In some embodiments, the active material layer 20 includes a first active material portion 21 and a second active material portion 22 arranged along a first direction Z, the first active material portion 21 is located on a side of the second active material portion 22 towards the first connecting portion 31, and the thickness of the first active material portion 21 away from the end of the second active material portion 22 is less than the thickness of the second active material portion 22.

[0283] In some examples, the first active material portion 21 can be substantially an equal-thickness structure, and the thickness of the first active material portion 21 is less than the thickness of the second active material portion 22, so that the first active material portion 21 and the second active material portion 22 form a stepped structure. In other examples, the thickness of the first active material portion 21 can also be steppedly reduced, so that the first active material portion 21 is a stepped structure. In yet other examples, the thickness of the first active material portion 21 can also slowly decrease in a direction away from the second active material portion 22, so that the thickness of the first active material portion 21 slowly decreases, and the outer shape of the first active material portion 21 is more rounded or smooth.

[0284] In the forming process of the first tab 1, the active material layer 20 can be rolled to compact the active material layer 20, and the first active material portion 21 can reduce the rolling pressure on the edge of the active material layer 20 and reduce the risk of cracking of the edge of the active material layer 20.

[0285] In some examples, the thickness of the first active material portion 21 decreases in a direction pointing from the active material layer 20 to the first connecting portion 31.

[0286] In some examples, the thickness of the first active material portion 21 at an end of the first active material portion 21 facing the second active material portion 22 is less than or equal to the thickness of the second active material portion 22.

[0287] In some examples, the first insulating member 4 covers at least part of the first active material portion 21. The first active material portion 21 has a small thickness, and covering the first active material portion 21 with the first insulating member 4 can improve the space utilization in the thickness direction Y of the current collector and reduce the pressure on the first insulating member 4 when the electrode assembly 101 swells, reduce stress concentration, reduce the risk of cracking of the active material layer 20 by the first insulating member 4, and improve the cycle performance of the battery cell 100.

[0288] In some examples, the first insulating member 4 is attached to the first active material portion 21.

[0289] In some examples, in a direction pointing from the first active material portion 21 to the second active material portion 22, the first insulating member 4 does not protrude at the junction of the first active material portion 21 and the second active material portion 22.

[0290] In some examples, in the first direction Z, the first insulating member 4 is spaced apart from the second active material portion 22.

[0291] Optionally, the first insulating member 4 has a first end facing the second active material portion 22, and in a direction pointing from the metal layer 12 to the active material layer 20, the first end does not exceed the surface of the second active material portion 22 facing away from the metal layer 12.

[0292] In some embodiments, the dimension of the portion of the active material layer 20 covered by the first insulating member 4 along the first direction Z is H, and 0.2 mm≤H≤1 mm.

[0293] In some examples, the value of H can be 0.2 mm, 1 mm, or any value between 0.2 mm and 1 mm, for example, but not limited to, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm.

[0294] Alternatively, 0.3 mm≤H≤0.8 mm.

[0295] By limiting H to be greater than or equal to 0.2 mm, the first insulating member 4 can cover the end surface of the active material layer 20 facing the first connecting portion 31, thereby blocking burrs around the end surface of the active material layer 20 facing the first connecting portion 31, and improving the use reliability of the battery monomer 100.

[0296] By limiting H to be greater than or equal to 0.2 mm, the first insulating member 4 can protect the edge region of the active material layer 20, and reduce the risk of material falling from the edge region of the active material layer 20.

[0297] By limiting H to be less than or equal to 1 mm, the area of the portion of the active material layer 20 covered by the first insulating member 4 can be limited, and the capacity loss can be reduced. In addition, by limiting H to be less than or equal to 1 mm, the portion of the active material layer 20 covered by the first insulating member 4 can not be too large, thereby reducing the weight and volume of the first insulating member 4, and facilitating reducing the impact of the first insulating member 4 on the energy density of the battery monomer 100.

[0298] By limiting H to be 0.2 mm-1 mm, the use reliability and energy density of the battery monomer 100 can be considered in the embodiments of the present application.

[0299] In some embodiments, the first connecting portion 31 is welded to the surface of the metal layer 12 away from the insulating base 11 and forms a first welding mark 51. The first welding mark 51 can transmit current between the first connecting portion 31 and the metal layer 12, thereby improving the overcurrent capacity and reducing heat generation.

[0300] In some embodiments, along the first direction Z, the first welding mark 51 is spaced apart from the active material layer 20, so that the first connecting portion 31 is not easy to be welded to the active material layer 20, which facilitates reducing the risk of problems such as false welding, and improving the connection reliability and overcurrent capacity of the metal layer 12 and the conductive member 30.

[0301] In some embodiments, the distance between the first welding mark 51 and the active material layer 20 along the first direction Z is S1, where 0.3mm≤S1≤5mm.

[0302] The value of S1 can be 0.3mm, 5mm, and any value between 0.3mm and 5mm, for example, the value of S1 can be but not limited to 0.3mm, 0.5mm, 1mm, 2mm, 2.5mm, 2.8mm, 3mm, 4mm, 5mm.

[0303] Setting S1 to be greater than or equal to 0.3mm can make the first welding mark 51 and the active material layer 20 have a distance, reduce the risk of the conductive member 30 being welded to the active material layer 20, reduce the problem of false welding, and be conducive to improving the connection reliability of the first connecting part 31 and the metal layer 12; setting S1 to be less than or equal to 5mm makes the distance between the first welding mark 51 and the active material layer 20 not too large, and in the case that the size of the metal layer 12 along the first direction Z is certain, the active material layer 20 can cover a larger area, which is conducive to improving the coverage area of the active material layer 20 on the metal layer 12 and improving the energy density of the battery monomer 100.

[0304] In some embodiments, 0.5mm≤S1≤2.8mm, the distance between the active material layer 20 and the first welding mark 51 is more reasonable, and the connection reliability of the conductive member 30 and the energy density of the battery monomer 100 can be better balanced.

[0305] In some examples, the first pole piece 1 is a positive pole piece, and there is a gap between the first welding mark 51 and the active material layer 20, which can be used to provide a spacing space between the conductive member 30 and the active material layer 20 to reduce the risk of lithium precipitation caused by the contact between the conductive member 30 and the active material layer 20, and in addition, the first welding mark 51 and the first end face of the first connecting part 31 towards the active material layer 20 can also provide a spacing space, so that the first welding mark 51 will not extend to the first end face 31a of the first connecting part 31, reducing the risk of the first end face 31a of the first connecting part 31 being welded through or cracked, which is conducive to reducing burrs generated by welding and improving the use reliability of the battery monomer 100.

[0306] In some examples, the first pole piece 1 is a negative pole piece, and there is a gap between the first welding mark 51 and the active material layer 20, which can provide a spacing space for the first welding mark 51 and the first end face 31a of the first connecting part 31, so that the first welding mark 51 will not extend to the first end face 31a of the first connecting part 31, reducing the risk of the first end face 31a of the first connecting part 31 being welded through or cracked, which is conducive to reducing burrs generated by welding and improving the use reliability of the battery monomer 100. The conductive member 30 can be in contact with the active material layer 20 or not.

[0307] In some embodiments, along the first direction Z, the first welding mark 51 is spaced apart from the first end surface 31a of the first connecting part 31.

[0308] The first welding mark 51 is spaced apart from the first end surface 31a of the first connecting part 31 by a distance, so that the first welding mark 51 does not extend to the first end surface 31a of the first connecting part 31, reducing the risk of being welded through or cracked at the first end surface 31a of the first connecting part 31, and facilitating the reduction of burrs generated by welding and improving the use reliability of the battery monomer 100.

[0309] In some embodiments, along the first direction Z, the distance between the first welding mark 51 and the first end surface 31a of the first connecting part 31 is S2, and 0.3mm≤S2≤1.2mm.

[0310] Limiting S2 to be greater than or equal to 0.3mm makes the first welding mark 51 and the first end surface 31a of the first connecting part 31 have a distance, so that the first welding mark 51 does not extend to the first end surface 31a of the first connecting part 31, reducing the risk of being welded through or cracked at the first end surface 31a of the first connecting part 31. Limiting S2 to be less than or equal to 1.2mm makes the distance between the first welding mark 51 and the first end surface 31a of the first connecting part 31 not too large, which is conducive to improving the coverage area of the active material layer 20 on the metal layer 12 and improving the energy density of the battery monomer 100.

[0311] The value of S2 can be 0.3mm, 1.2mm and any value between 0.3mm-1.2mm, for example, the value of S2 can be but not limited to 0.3mm, 0.6mm, 0.8mm, 1mm, 1.2mm.

[0312] Limiting S2 to be 0.3mm-1.2mm can better balance the use reliability and energy density of the battery monomer 100.

[0313] In some embodiments, the first insulating component 4 covers at least part of the first welding mark 51. The first insulating component 4 covers the surface of the first connecting part 31 away from the metal layer 12, and covers at least part of the first welding mark 51. The first insulating component 4 can cover part of the first welding mark 51, or cover the entire first welding mark 51.

[0314] Optionally, the first insulating component 4 completely covers the first welding mark 51.

[0315] The first connecting part 31 is welded to the metal layer 12, and a pointed protrusion, metal debris or the like is easily generated on the surface of the first welding mark 51. The first insulating part 4 of the embodiment covers the surface of the first welding mark 51, so as to reduce the risk that the pointed protrusion, metal debris or the like on the surface of the first welding mark 51 pierces the separator 3, and further reduce the risk that the pointed protrusion, metal debris or the like contacts the second pole piece 2, thereby reducing the short circuit risk of the battery monomer 100 and improving the use reliability of the battery monomer 100.

[0316] In some embodiments, the first insulating part 4 is connected to the first pole piece 1. The first insulating part 4 can be connected to the metal layer 12, or can be connected to the conductive member 30, or can be connected to the active material layer 20. For example, the first insulating part 4 can be connected to the first pole piece 1 by adhesion or pasting or the like.

[0317] The first insulating part 4 is connected to the first pole piece 1, so that the first insulating part 4 is fixed, thereby stably blocking the pointed protrusion at the first end surface 31a, and facilitating the improvement of the use reliability of the battery monomer 100.

[0318] In some embodiments, along the first direction Z, the size of the first insulating part 4 is W, and 3mm≤W≤9mm.

[0319] The value of W can be 3mm, 9mm and 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 or 9mm.

[0320] The W is limited to be greater than or equal to 3mm, so that the first insulating part 4 has a certain size, and the first insulating part 4 can better block the pointed protrusion at the first end surface 31a, thereby improving the internal insulation effect of the battery monomer 100. The W is limited to be less than or equal to 9mm, so as to limit the size of the first insulating part 4 along the first direction Z, thereby facilitating the reduction of the volume and weight occupied by the first insulating part 4 and the improvement of the energy density of the battery monomer 100.

[0321] By adopting the technical scheme of the embodiment, the insulation reliability and the energy density of the battery monomer 100 can be simultaneously considered.

[0322] In some embodiments, 4.5mm≤W≤6.5mm. Along the first direction Z, the size of the first insulating part 4 is reasonable, and the insulation reliability and the energy density of the battery monomer 100 can be better considered.

[0323] In some embodiments, the first insulating part 4 has an equal-width structure.

[0324] In some embodiments, the first insulating part 4 can be a rectangular adhesive tape.

[0325] In some embodiments, the conductive member 30 further comprises at least one second connecting portion 32 connected to the first connecting portion 31, the second connecting portion 32 is located on the side of the first connecting portion 31 away from the active material layer 20 in the first direction Z; the second connecting portion 32 is electrically connected with the electrode lead-out portion 2011.

[0326] Exemplarily, the first connecting portion 31 and the second connecting portion 32 are arranged and connected in the first direction Z. In the direction of the active material layer 20 pointing to the first connecting portion 31, the second connecting portion 32 protrudes from the metal layer 12 as a whole.

[0327] The connection between the second connecting portion 32 and the electrode lead-out portion 2011 can be achieved by direct welding, or by welding through a conductive piece (such as a jumper, etc.). By using the welding method, the connection operation is convenient and facilitates processing and manufacturing. Of course, the second connecting portion 32 and the electrode lead-out portion 2011 can also be connected by other methods.

[0328] In some examples, the first connecting portion 31 can be covered on the metal layer 12 and welded with the metal layer 12, and the second connecting portion 32 can be led out from the end of the first connecting portion 31 away from the active material layer 20 in the first direction Z, so as to protrude out of the insulating base body 11; in the thickness direction Y of the current collector 10, the projection of the first connecting portion 31 is located within the projection of the metal layer 12, and the projection of the second connecting portion 32 is located outside the projection range of the metal layer 12; the connection positions of the metal layer 12 and the electrode lead-out portion 2011 on the conductive member 30 are different, which facilitates the connection and can reduce the mutual influence between the two connections, and is beneficial to the connection reliability.

[0329] In some cases, in the wound electrode assembly 101, the insulating base body 11 insulates the adjacent two turns of the metal layer 12, which makes it difficult to directly connect the adjacent two turns of the metal layer 12 to transmit current outward across the insulating base body 11, resulting in poor conductivity, low fast-charging performance, and easy local overheating, which affects the use reliability of the battery monomer 100; while the battery monomer 100 of the embodiment of the application utilizes the welding of the first connecting portion 31 of the conductive member 30 with the metal layer 12, and the second connecting portion 32 of the conductive member 30 protrudes out of the insulating base body 11, so that the second connecting portion 32 can electrically conduct the adjacent two turns of the metal layer 12, thereby breaking the insulation limitation of the insulating base body 11, effectively improving the conductivity of the first electrode tab 1, improving the fast-charging performance of the battery monomer 100, reducing the heat generation of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0330] In the lamination type electrode assembly 101, the insulating base body 11 insulates and separates the two adjacent metal layers 12, which makes it difficult to directly connect the two adjacent metal layers 12 to externally transmit the current, resulting in poor conductivity, low fast charging performance, and easy local overheating, which affects the use reliability of the battery monomer 100. The battery monomer 100 of the embodiment of the application uses the first connecting part 31 of the conductive member 30 to be welded to the metal layer 12, and the second connecting part 32 of the conductive member 30 protrudes out of the insulating base body 11. In this way, the second connecting part 32 can be used to electrically conduct the two adjacent metal layers 12, thereby breaking the insulation limit of the insulating base body 11, effectively improving the conductivity of the first electrode sheet 1, improving the fast charging performance of the battery monomer 100, reducing the heat production of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0331] The second connecting part 32 protrudes out of the metal layer 12, which can facilitate the connection of the second connecting part 32 with the electrode lead-out part 2011, and is more convenient to process and manufacture. At the same time, it can also reduce the risk of false welding and other problems, which is conducive to improving the connection reliability of the metal layer 12 and the conductive member 30, and also conducive to improving the overcurrent capacity of the first electrode sheet 1 and the fast charging performance of the battery monomer 100.

[0332] In some embodiments, the first connecting part 31 and the second connecting part 32 are one.

[0333] In other embodiments, the first connecting part 31 includes a plurality of first connecting sub-parts 311, and the plurality of first connecting sub-parts 311 are arranged at intervals along a second direction X perpendicular to the first direction Z and the thickness direction Y of the current collector. Each first connecting sub-part 311 is connected to the metal layer 12. The number of second connecting parts 32 is a plurality, and each first connecting sub-part 311 is connected to each second connecting part 32 one by one.

[0334] By arranging a plurality of second connecting parts 32, the overcurrent area can be increased, the overcurrent capacity of the conductive member 30 can be improved, the fast charging performance of the battery monomer 100 can be improved, the heat production of the battery monomer 100 can be reduced, and the use reliability of the battery monomer 100 can be improved.

[0335] In some embodiments, the current collector 10 includes two metal layers 12 arranged on opposite sides of the insulating base body 11 along the thickness direction Y of the current collector. The first electrode sheet 1 includes two active material layers 20 and two conductive members 30, the two active material layers 20 are arranged on the two metal layers 12 respectively, and the first connecting parts 31 of the two conductive members 30 are connected to the two metal layers 12 respectively.

[0336] The two conductive members 30 can respectively lead out the current of the two metal layers 12, thereby improving the overcurrent capacity and improving the fast charging performance of the battery monomer 100.

[0337] In some embodiments, the electrode assembly 101 comprises two first insulating components 4, which are respectively attached to the first connecting portions 31 of the two conductive members 30.

[0338] The two first insulating components 4 can be directly connected or not directly connected.

[0339] The two first insulating components 4 can respectively cover burrs at the first end surfaces 31a of the two first connecting portions 31, thereby reducing the possibility of the burrs piercing the separator 3 and contacting the second pole piece 2, and reducing the risk of short circuit.

[0340] In some embodiments, a portion of the two first insulating components 4 is attached, so as to reduce the risk of burrs extending from between the two first insulating components 4 and improve reliability.

[0341] In some embodiments, a portion of the two first insulating components 4 is connected, so as to improve the stability of the first insulating components 4 and reduce the risk of the first insulating components 4 falling off the first pole piece 1.

[0342] In some embodiments, a portion of the two first insulating components 4 is attached and connected.

[0343] In some embodiments, the conductive member 30 further comprises a second connecting portion 32 connected to the first connecting portion 31, and the second connecting portion 32 is located on the side of the first connecting portion 31 away from the active material layer 20 in the first direction Z; the second connecting portion 32 is electrically connected to the electrode lead-out portion 2011. The second connecting portions 32 of the two conductive members 30 are welded and form second welding marks 52.

[0344] In some examples, the portion of the conductive member 30 protruding from the metal layer 12 in the direction pointing to the first connecting portion 31 of the active material layer 20 forms the second connecting portion 32, so that the second connecting portions 32 of the two conductive members 30 can be directly close to each other and welded together, and the trace left by welding is the second welding mark 52. The second connecting portions 32 of the two conductive members 30 can be welded by ultrasonic welding, laser welding, etc.

[0345] The second connecting portions 32 of the two conductive members 30 can connect the metal layers 12 located on the opposite sides of the insulating base body 11, thereby breaking the insulation limitation of the insulating base body 11, effectively improving the electrical conductivity of the first pole piece 1, improving the fast-charging performance of the battery monomer 100, reducing the heat generation of the battery monomer 100, and improving the use reliability of the battery monomer 100.

[0346] In some embodiments, the metal layer 12 includes a first metal portion 121 and a second metal portion 122 arranged and connected along the first direction Z, the first metal portion 121 is covered with the active material layer 20, and the second metal portion 122 is not covered with the active material layer 20. The first connecting portion 31 is welded to the second metal portion 122 and forms the first welding mark 51.

[0347] For example, the second metal portion 122 can have a size along the second direction X that is less than or equal to a size of the first metal portion 121 along the second direction X.

[0348] The first connecting portion 31 is stacked on and welded to the surface of the metal layer 12 opposite the insulating base 11, and the trace formed by the welding is the first welding mark 51.

[0349] Welding the second metal portion 122 and the first connecting portion 31 can simplify the manufacturing process of the first electrode tab 1 and improve the current-carrying capacity between the metal layer 12 and the first connecting portion 31. By providing the second metal portion 122 that is not covered with the active material layer 20, the influence of welding on the active material layer 20 can be reduced.

[0350] The metal layer 12 has a small thickness and a large surface opposite the insulating base 11. Stacking and welding the first connecting portion 31 and the second metal portion 122 can increase the welding area between the conductive member 30 and the metal layer 12, improve the current-carrying area between the conductive member 30 and the metal layer 12, and thus improve the current-carrying capacity of the first electrode tab 1 and the fast-charging performance of the battery device 1100.

[0351] In some embodiments, the thickness of the first connecting portion 31 is greater than the thickness of the second metal portion 122.

[0352] In some embodiments, the thickness of the conductive member 30 is greater than the thickness of the metal layer 12.

[0353] In some embodiments, the second metal portion 122 includes at least one protrusion 1221, and along the second direction X, the sum of the sizes of all the protrusions 1221 is less than the size of the first metal portion 121, and the second direction X is perpendicular to the first direction Z and the thickness direction Y of the current collector.

[0354] In some examples, the second metal portion 122 includes one protrusion 1221.

[0355] In other examples, the second metal portion 122 includes a plurality of protrusions 1221, and the plurality of protrusions 1221 are arranged at intervals along the second direction X.

[0356] For example, the first metal part 121 has a dimension L1 along the second direction X, and the protrusion 1221 has a dimension l1 along the second direction X towards the end of the first metal part 121. The number of the protrusions 1221 is n, n being a positive integer. L1 > n x l1. Optionally, n is 1, 2, 4, 5, 8, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100.

[0357] The protrusions 1221 can be directly connected to the first metal part 121, or indirectly connected to the first metal part 121 through other parts of the second metal part 122.

[0358] In some embodiments, the first connecting part 31 comprises at least one first connecting sub-part 311, the first connecting sub-part 311 being located on the side of the protrusion 1221 away from the insulating base 11, and the first connecting sub-part 311 corresponding to the protrusion 1221 one-to-one.

[0359] For example, the first connecting sub-part 311 can be the part of the first connecting part 31 overlapping the protrusion 1221 in the thickness direction Y of the current collector.

[0360] The first connecting sub-part 311 covers the protrusion 1221. The first connecting sub-part 311 can completely cover the protrusion 1221, or only cover a part of the protrusion 1221.

[0361] The number of the first connecting sub-parts 311 can be the same as the number of the protrusions 1221. In some examples, there is one first connecting sub-part 311 and one protrusion 1221. In other examples, there are multiple first connecting sub-parts 311 and multiple protrusions 1221, and the multiple first connecting sub-parts 311 are arranged one-to-one corresponding to the multiple protrusions 1221.

[0362] The first connecting sub-part 311 can be directly fixed to the protrusion 1221, for example, the first connecting sub-part 311 can be welded to the protrusion 1221. Alternatively, the first connecting sub-part 311 can only be attached to the protrusion 1221.

[0363] By arranging the protrusion 1221, the space and volume occupied by the first pole piece 1 can be reduced, and the energy density of the battery monomer 100 can be improved. By arranging the first connecting sub-part 311, the overcurrent area between the first connecting part 31 and the second metal part 122 can be increased, and the overcurrent capacity can be improved.

[0364] In some embodiments, the first connecting sub-part 311 completely covers the protrusion 1221.

[0365] In some embodiments, the number of protrusions 1221 is multiple, and the multiple protrusions 1221 are arranged at intervals along the second direction X. The first connecting portion 31 includes multiple first connecting sub-portions 311, and the multiple first connecting sub-portions 311 are arranged at intervals along the second direction X, and the multiple first connecting sub-portions 311 correspond to the multiple protrusions 1221 one by one.

[0366] By arranging the multiple protrusions 1221 and the multiple first connecting sub-portions 311, the flow area between the first connecting portion 31 and the second metal portion 122 can be increased, the flow capacity can be improved, and the fast charging performance of the battery monomer 100 can be improved.

[0367] Exemplarily, the multiple protrusions 1221 are arranged at intervals along the second direction X, which is beneficial to divide the first metal portion 121 into multiple regions along the second direction X, and one region can correspond to one protrusion 1221. The electrons in each region can be transmitted to the electrode lead-out portion 2011 through the corresponding protrusion 1221, so that the electrons in the first metal portion 121 are transmitted in a region-by-region manner. The transmission path of the electrons in each region is transmitted to the corresponding protrusion 1221, which is short, and is beneficial to reduce the transmission distance of the electrons, reduce the overall resistance of the first electrode sheet 1, and improve the fast charging performance and use reliability of the battery monomer 100.

[0368] In some examples, after the first electrode sheet 1 is wound or stacked, the multiple protrusions 1221 are stacked together, and at the same time, the multiple second connecting portions 32 are also stacked together, so as to break the insulation limit of the insulation base body 11, effectively improve the conductivity of the first electrode sheet 1, improve the fast charging performance of the battery monomer 100, reduce the heat generation of the battery monomer 100, and improve the use reliability of the battery monomer 100.

[0369] In some embodiments, the number of second connecting portions 32 is multiple, and each first connecting sub-portion 311 corresponds to one second connecting portion 32 one by one; and each first connecting sub-portion 311 is welded to the surface of each protrusion 1221 away from the insulation base body 11 one by one. The number of first connecting sub-portions 311, the number of second connecting portions 32, and the number of protrusions 1221 are the same, one first connecting sub-portion 311 corresponds to one protrusion 1221, and one first connecting sub-portion 311 corresponds to one second connecting portion 32.

[0370] In some embodiments, the first insulating member 4 includes at least one first insulating sub-portion 41, and the first insulating sub-portion 41 covers the surface of the first connecting sub-portion 311 away from the protrusion 1221, and the first insulating sub-portion 41 corresponds to the first connecting sub-portion 311 one by one.

[0371] Exemplarily, the first insulating sub-portion 41 can be the portion of the first insulating member 4 overlapping the first connecting sub-portion 311 in the thickness direction Y of the current collector.

[0372] The first insulating sub 41 can completely cover the first connecting sub 311, or can only cover a part of the first connecting sub 311.

[0373] The number of the first connecting sub 311, the number of the protruding sub 1221, and the number of the first insulating sub 41 can be the same. In some examples, the first connecting sub 311, the protruding sub 1221, and the first insulating sub 41 are all one. In other examples, the first connecting sub 311, the protruding sub 1221, and the first insulating sub 41 are all multiple, the multiple first connecting subs 311 are arranged one-to-one with the multiple protruding subs 1221, and the multiple first insulating subs 41 are arranged one-to-one with the multiple first connecting subs 311.

[0374] The first insulating sub 41 can cover the first connecting sub 311 to reduce the risk of the first connecting sub 311 being in conduction with the second pole piece 2 and improve the use reliability of the battery monomer 100.

[0375] In some embodiments, the first insulating sub 41 completely covers the first connecting sub 311.

[0376] In some embodiments, the number of the protruding sub 1221 is multiple, and the multiple protruding subs 1221 are arranged at intervals along the second direction X. The first connecting sub 31 includes multiple first connecting subs 311 arranged at intervals along the second direction X, and the multiple first connecting subs 311 correspond one-to-one to the multiple protruding subs 1221. The first insulating component 4 includes multiple first insulating subs 41 arranged along the second direction X, the first insulating sub 41 covers the surface of the first connecting sub 311 away from the protruding sub 1221, and the first insulating sub 41 is arranged one-to-one with the first connecting sub 311.

[0377] The multiple first insulating subs 41 respectively cover the multiple first connecting subs 311 to reduce the risk of the first connecting sub 311 being in conduction with the second pole piece 2 and improve the use reliability of the battery monomer 100.

[0378] In some embodiments, the first insulating component 4 further includes a second insulating sub 42 connected to the first insulating sub 41, and the second insulating sub 42 is located on the side of the first insulating sub 41 facing the active material layer 20 along the first direction Z.

[0379] The second insulating sub 42 can be one or multiple. In some examples, the second insulating sub 42 is one and continuously extends along the second direction X, and the second insulating sub 42 connects the multiple first connecting subs 311. In other examples, the second insulating sub 42 is multiple, and the multiple second insulating subs 42 are arranged one-to-one with the multiple first insulating subs 41.

[0380] The second insulating sub-section 42 is arranged to protrude from the first connecting sub-section 311 in the direction in which the first insulating member 4 points to the active material layer 20 along the first connecting section 31, so as to reduce the risk of the first connecting sub-section 311 being in conduction with the second pole piece 2. In addition, the second insulating sub-section 42 can also be used to cover the burrs at the first end surface 31a, so as to reduce the possibility of the burrs piercing the separator 3 and being in contact with the second pole piece 2, and further reduce the risk of short circuit.

[0381] In some embodiments, the second insulating sub-section 42 can be arranged to be spaced apart from the metal layer 12, or can be attached to the metal layer 12. Optionally, at least part of the second insulating sub-section 42 is attached to the part of the metal layer 12 between the first connecting section 31 and the active material layer 20.

[0382] In some embodiments, the end of the second insulating sub-section 42 away from the first insulating sub-section 41 can cover the active material layer 20.

[0383] In some embodiments, the first insulating member 4 includes a plurality of first insulating sub-sections 41 arranged along the second direction X. The second insulating sub-section 42 continuously extends along the second direction X and is connected to the plurality of first insulating sub-sections 41.

[0384] The continuous arrangement of the second insulating sub-section 42 can increase the insulating area and reduce the risk of short circuit. The second insulating sub-section 42 connects the plurality of first insulating sub-sections 41 into a whole, so as to reduce the risk of the first insulating sub-sections 41 falling off from the first connecting sub-section 311 and improve the insulating reliability.

[0385] In some embodiments, the first insulating member 4 further includes a third insulating sub-section 43 connected to the first insulating sub-section 41, and the third insulating sub-section 43 is arranged along the second direction X with the first insulating sub-section 41.

[0386] The third insulating sub-section 43 can be one or a plurality.

[0387] The arrangement of the third insulating sub-section 43 can make the first insulating member 4 protrude from the first connecting sub-section 311 in the second direction X, so as to cover the burrs at the end of the first connecting sub-section 311 in the second direction X, reduce the possibility of the burrs piercing the separator 3 and being in contact with the second pole piece 2, further reduce the risk of short circuit, and improve the reliability of the battery monomer 100.

[0388] In some embodiments, the third insulating sub-section 43 is a plurality, and both ends of the first insulating sub-section 41 along the second direction X are connected to the third insulating sub-section 43. The first insulating member 4 can cover both ends of the first connecting sub-section 311 along the second direction X.

[0389] In some embodiments, the third sub-insulating part 43 does not overlap with the current collector 10 or the conductive member 30 in the thickness direction Y of the current collector 10.

[0390] In some embodiments, the two first insulating parts 4 are two, and the two first insulating parts 4 are respectively attached to the first connecting parts 31 of the two conductive members 30. The third sub-insulating parts 43 of the two first insulating parts 4 are attached to reduce the risk of burrs extending from between the two third sub-insulating parts 43 and improve reliability.

[0391] As an example, the third sub-insulating parts 43 of the two first insulating parts 4 can be attached together by pasting, static adsorption or other means.

[0392] After the third sub-insulating parts 43 of the two first insulating parts 4 are attached, the metal debris at the two ends of the first connecting sub-parts 311 in the second direction X can be covered, so that the metal debris is not easy to fall into the electrode assembly 101, and the risk of short circuit of the battery monomer 100 can be better reduced.

[0393] In some embodiments, the third sub-insulating parts 43 of the two first insulating parts 4 are connected to improve the stability of the first insulating part 4 and reduce the risk of the first insulating part 4 falling off the first tab 1.

[0394] In some embodiments, the third sub-insulating parts 43 of the two first insulating parts 4 are attached and connected. Optionally, the third sub-insulating parts 43 of the two first insulating parts 4 are bonded.

[0395] In some embodiments, the first insulating part 4 includes a plurality of third sub-insulating parts 43 arranged in the second direction X, and each first sub-insulating part 41 is connected to two third sub-insulating parts 43 at the two ends in the second direction X.

[0396] The two third sub-insulating parts 43 can respectively cover the burrs at the two ends of the first connecting sub-parts 311 in the second direction X, thereby reducing the possibility of the burrs piercing the separator 3 and contacting the second tab 2, reducing the risk of short circuit, and improving the reliability of the battery monomer 100.

[0397] In some embodiments, the plurality of third sub-insulating parts 43 of the two first insulating parts 4 are arranged one by one.

[0398] In some embodiments, the plurality of first sub-insulating parts 41 and the plurality of third sub-insulating parts 43 are alternately arranged in the second direction X, and two adjacent first sub-insulating parts 41 are connected by a third sub-insulating part 43.

[0399] The plurality of third insulating sub-parts 43 connect the plurality of first insulating sub-parts 41 into one body, which can increase the insulating area and reduce the risk of the first insulating sub-parts 41 falling off from the first connecting sub-part 311, thereby improving the insulating reliability.

[0400] The first insulating part 4 is integrally and continuously arranged, which can bind the first connecting sub-part 311, reduce the deformation of the first connecting sub-part 311, reduce the risk of the first connecting sub-part 311 being inserted into the active material layer 20 and the second pole piece 2, and reduce the risk of short circuit.

[0401] In some embodiments, the first insulating part 4 further comprises a fourth insulating sub-part 44 connected to the first insulating sub-part 41, and the fourth insulating sub-part 44 is located on the side of the first insulating sub-part 41 away from the active material layer 20 along the first direction Z.

[0402] The fourth insulating sub-part 44 can be one or a plurality.

[0403] For example, the fourth insulating sub-part 44 and the second insulating sub-part 42 are respectively connected to the two ends of the first insulating sub-part 41 along the first direction Z.

[0404] In the direction in which the active material layer 20 points to the first connecting part 31, the fourth insulating sub-part 44 as a whole exceeds the first connecting sub-part 311. By arranging the fourth insulating sub-part 44, the insulating effect can be improved.

[0405] In some embodiments, the fourth insulating sub-part 44 can be attached to the conductive member 30. For example, the fourth insulating sub-part 44 is attached to the second connecting part 32.

[0406] In some embodiments, the first insulating part 4 further comprises a plurality of first insulating sub-parts 41 and a plurality of fourth insulating sub-parts 44, the plurality of first insulating sub-parts 41 and the plurality of fourth insulating sub-parts 44 are arranged one by one, and the first insulating sub-part 41 is connected to the corresponding fourth insulating sub-part 44. The fourth insulating sub-part 44 is located on the side of the first insulating sub-part 41 away from the active material layer 20 along the first direction Z.

[0407] Optionally, the first insulating part 4 further comprises a plurality of third insulating sub-parts 43, the plurality of third insulating sub-parts 43 and the plurality of fourth insulating sub-parts 44 are alternately arranged along the second direction X, and the adjacent two fourth insulating sub-parts 44 are connected by one third insulating sub-part 43.

[0408] In some embodiments, the first connecting sub-part 311 is welded to the protruding part 1221 and forms a first welding part 511, the first welding part 51 comprises the first welding part 511; and the first insulating sub-part 41 covers at least part of the first welding part 511.

[0409] Exemplarily, the first connecting sub-part 311 is stacked on the surface of the protruding part 1221 away from the insulating base 11 and is welded with the protruding part 1221, and the trace formed by welding is the first welding mark part 511.

[0410] In some examples, the first connecting sub-part 311 can be welded with the protruding part 1221 as a whole; alternatively, in other examples, the first connecting sub-part 311 can be welded with the protruding part 1221 at one part and not welded with the protruding part 1221 at another part.

[0411] In some examples, the first connecting part 31 can be welded with the protruding part 1221 only. Alternatively, the first connecting part 31 can also be welded with other parts of the metal layer 12.

[0412] The first insulating sub-part 41 can cover part of the first welding mark part 511 or cover the entire first welding mark part 511.

[0413] Exemplarily, the first welding mark part 511 can be a one-piece structure, or alternatively, the first welding mark part 511 can include multiple spaced welding spots or welding lines.

[0414] The first connecting sub-part 311 and the protruding part 1221 are connected by welding, which is simple and convenient for the manufacturing of the first pole piece 1; the first connecting sub-part 311 and the protruding part 1221 can directly flow through the first welding mark part 511, which is conducive to improving the flow capacity between the first connecting sub-part 311 and the protruding part 1221; the first insulating sub-part 41 can block the burrs, metal debris and other structures on the first welding mark part 511, thereby reducing the risk of these structures penetrating through the separator 3 and contacting the second pole piece 2, and improving the use reliability of the battery monomer 100.

[0415] In some embodiments, along the first direction Z, both ends of the first welding mark part 511 do not exceed the first insulating sub-part 41. The embodiments of the application can reduce the exposed area of the first welding mark part 511, reduce the risk of the first welding mark part 511 piercing the separator 3, and improve the use reliability of the battery monomer 100.

[0416] In some embodiments, along the second direction X, both ends of the first welding mark part 511 do not exceed the first insulating sub-part 41.

[0417] In some embodiments, along the second direction X, the first welding mark part 511 extends from one side of the protruding part 1221 to the other side of the protruding part 1221. The first welding mark part 511 has a large size along the second direction X, which is conducive to improving the flow area between the first connecting sub-part 311 and the protruding part 1221, improving the flow capacity between the first connecting sub-part 311 and the protruding part 1221, reducing the risk of heating, and improving the fast charging performance and use reliability of the battery monomer 100.

[0418] In some embodiments, the projection of the first welding portion 511 falls within the projection of the protruding portion 1221 in the thickness direction Y of the current collector.

[0419] In some embodiments, the first connecting sub-portions 311 and the protruding portions 1221 are both multiple and are arranged one-to-one. Correspondingly, the first welding portions 511 are also multiple and are arranged one-to-one with the multiple first connecting sub-portions 311.

[0420] In some embodiments, in the process of manufacturing the first tab 1, the long strip-shaped conductive member can be welded with the edge of the current collector by ultrasonic welding (for example, double-roller continuous ultrasonic welding or other welding methods) and form equal-width welding, and then the conductive member is cut by laser die-cutting or other cutting methods to form a predetermined shape, facilitating the connection of the conductive member with the electrode lead-out portion. After cutting, the equal-width welding will form multiple first welding portions.

[0421] In some embodiments, the first insulating member 4 completely covers the first welding portion 511.

[0422] In some embodiments, the second metal portion 122 further comprises a transition portion 1222 connected between the first metal portion 121 and the protruding portion 1221. In the second direction X, the size of the transition portion 1222 is greater than the sum of the sizes of all the protruding portions 1221.

[0423] In the second direction X, the size of the transition portion 1222 can be L2, and the size of the end of the protruding portion 1221 towards the transition portion 1222 in the second direction X is l1. The number of the protruding portions 1221 is n, and n is a positive integer. L2 > n x l1.

[0424] The first metal portion 121, the transition portion 1222, and the protruding portion 1221 are arranged in the first direction Z.

[0425] In some embodiments, in the second direction X, the size of the first metal portion 121 is L1, and the size of the transition portion 1222 is L2, and 0.8 ≤ L2 / L1 ≤ 1.

[0426] 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, 1.

[0427] In some examples, L2 = L1. In the second direction X, the size L2 of the transition portion 1222 is equal to the size L1 of the first metal portion 121; optionally, in the second direction X, the two ends of the transition portion 1222 are flush with the first metal portion 121.

[0428] In some examples, L2 < L1. Optionally, along the second direction X, the transition portion 1222 can be located at a middle position of the first metal portion 121, and both ends of the transition portion 1222 are not flush with both ends of the first metal portion 121. Alternatively, along the second direction X, the transition portion 1222 can be arranged offset to one end of the first metal portion 121, such that one end of the transition portion 1222 is flush with one end of the first metal portion 121, and the other end of the transition portion 1222 is not flush with the other end of the first metal portion 121.

[0429] In some examples, the first connecting portion 31 includes a second connecting sub-portion 312, which is located on a side of the transition portion 1222 away from the insulating substrate 11 along the thickness direction Y of the current collector, and the first connecting sub-portion 311 is connected to an end face of the second connecting sub-portion 312 away from the active material layer 20.

[0430] The second connecting sub-portion 312 can be one or multiple. In some examples, the first connecting sub-portion 311 is multiple and arranged spaced apart along the second direction X, the second connecting sub-portion 312 is one and continuously extends along the second direction X, and the second connecting sub-portion 312 connects the multiple first connecting sub-portions 311. In other examples, the first connecting sub-portion 311 and the second connecting sub-portion 312 are both multiple, and the multiple first connecting sub-portions 311 and the multiple second connecting sub-portions 312 are arranged one-to-one.

[0431] As an example, the second connecting sub-portion 312 can be directly fixedly connected to the transition portion 1222, or can be arranged in abutment without being directly fixed.

[0432] As an example, the second connecting sub-portion 312 is connected to the surface of the transition portion 1222 away from the insulating substrate 11 by welding, conductive adhesive bonding, or other means, to realize electrical connection between the second connecting sub-portion 312 and the transition portion 1222.

[0433] In the cycle process of the battery monomer 100, part of the current can be transmitted between the transition portion 1222 and the second connecting sub-portion 312, thereby reducing the overcurrent pressure between the protruding portion 1221 and the first connecting sub-portion 311, and facilitating reduction of heat generation of the protruding portion 1221, and improvement of the fast-charging performance and use reliability of the battery monomer 100.

[0434] In some examples, the second connecting sub-portion 312 is connected to the transition portion 1222.

[0435] As an example, 0.8 ≤ L2 / L1 ≤ 1. The larger the size L2 of the transition portion 1222, the larger the connection area of the transition portion 1222 and the second connecting sub-portion 312 can be arranged, and the better the overcurrent capacity between the transition portion 1222 and the second connecting sub-portion 312.

[0436] When L2 / L1 is set to 0.8-1, the transition portion 1222 has a large size in the second direction X, which is beneficial to increase the connection area between the second sub-connection portion 312 and the transition portion 1222, improve the current-carrying capacity at the connection between the second sub-connection portion 312 and the transition portion 1222, improve the current-carrying capacity of the first tab 1, reduce the heat generation of the battery monomer 100, and improve the fast-charging performance of the battery monomer 100.

[0437] In some embodiments, L2=L1. The embodiments of the present application can make the size of the transition portion 1222 in the second direction X larger, which is beneficial to design a larger connection area between the second sub-connection portion 312 and the transition portion 1222, and the current-carrying capacity at the connection between the second sub-connection portion 312 and the transition portion 1222 is optimal, which can effectively improve the current-carrying capacity of the first tab 1, reduce the heat generation of the battery monomer 100, and improve the fast-charging performance of the battery monomer 100.

[0438] In some embodiments, the second sub-connection portion 312 is one. The size of the second sub-connection portion 312 in the second direction X is equal to the size of the transition portion 1222 in the second direction X.

[0439] In some embodiments, along the first direction Z, the end surface of the second sub-connection portion 312 facing the active material layer 20 is the first end surface 31a. The first insulating member 4 can block burrs at the first end surface 31a, reduce the possibility of burrs piercing the separator 3 and contacting the second tab 2, and thus reduce the risk of short circuit.

[0440] In some embodiments, along the direction from the first metal portion 121 to the second metal portion 122, the first insulating member 4 protrudes from the end surface of the second sub-connection portion 312 facing away from the active material layer 20. The first insulating member 4 can block burrs at the end surface of the second sub-connection portion 312 facing away from the active material layer 20, reduce the possibility of burrs piercing the separator 3 and contacting the second tab 2, and thus reduce the risk of short circuit.

[0441] In some embodiments, at least part of the first insulating member 4 is attached to the second sub-connection portion 312.

[0442] In some embodiments, the first insulating member 4 includes a second insulating sub-portion 42, the second insulating sub-portion 42 covers the second sub-connection portion 312, and along the direction from the second metal portion 122 to the first metal portion 121, the second insulating sub-portion 42 protrudes from the first end surface 31a.

[0443] The first insulating member 4 can include or not include the first insulating sub-portion 41.

[0444] The second insulating sub-portion 42 can completely cover the first end surface 31a, or only cover part of the first end surface 31a.

[0445] The second insulating sub 42 can block burrs at the first end surface 31a, reduce the possibility of burrs piercing the separator 3 and contacting the second tab 2, and thus reduce the risk of short circuit.

[0446] In some embodiments, the second insulating sub 42 completely covers the second connecting sub 312.

[0447] In some embodiments, the second insulating sub 42 completely covers the transition 1222.

[0448] In some embodiments, in the second direction X, the second insulating sub 42 protrudes from the second connecting sub 312. The second insulating sub 42 can block burrs at both ends of the second connecting sub 312 in the second direction X, reduce the possibility of burrs piercing the separator 3 and contacting the second tab 2, and thus reduce the risk of short circuit.

[0449] Optionally, the second insulating sub 42 continuously extends in the second direction X, the size of the second insulating sub 42 in the second direction X is greater than the size of the second connecting sub 312 in the second direction X, and the size of the second insulating sub 42 in the second direction X is greater than the size of the transition 1222 in the second direction X.

[0450] Optionally, there are two first insulating components 4. The second insulating subs 42 of the two first insulating components 4 are fitted and bonded to the portions of the second connecting sub 312 protruding in the second direction X.

[0451] In some embodiments, the first insulating component 4 further comprises a first insulating sub 41 and a third insulating sub 43, and the first insulating sub 41 and the third insulating sub 43 are connected to the second insulating sub 42. In the first direction Z, the first insulating sub 41 and the third insulating sub 43 are both located on the side of the second insulating sub 42 away from the active material layer 20. The first insulating sub 41 covers the surface of the first connecting sub 311 away from the protruding part 1221. The first insulating sub 41 and the third insulating sub 43 are arranged and connected in the second direction X.

[0452] The third insulating sub 43 can block burrs on the end surface of the second connecting sub 312 away from the active material layer 20, or block burrs on the end of the first connecting sub 311 in the second direction X, thereby reducing the possibility of burrs piercing the separator 3 and contacting the second tab 2, reducing the risk of short circuit, and improving the use reliability of the battery monomer 100.

[0453] Optionally, the first insulating sub 41 and the third insulating sub 43 are both multiple. The multiple first insulating subs 41 and the multiple third insulating subs 43 are alternately arranged in the second direction X.

[0454] As an example, referring to FIG. 14 and FIG. 15, the junction lines of the first insulating sub-portion 41, the second insulating sub-portion 42, the third insulating sub-portion 43 and the fourth insulating sub-portion 44 are shown by dashed lines D1, D2, D3, D4, D5, D6. Among them, the dashed line D1 corresponds to the end surface of the second connecting sub-portion 312 facing the first connecting sub-portion 311, the dashed line D2 corresponds to the junction of the first connecting portion 31 and the second connecting portion 32 (the junction of the first connecting portion 31 and the second connecting portion 32 corresponds to the end surface of the protruding portion 1221 facing away from the transition portion 1222), D3 and D4 correspond to the two ends of the first connecting sub-portion 311 along the second direction X respectively, and D5 and D6 correspond to the two ends of the second connecting portion 32 along the second direction X respectively.

[0455] In some embodiments, the second connecting sub-portion 312 is welded to the surface of the transition portion 1222 facing away from the insulating base body 11 and forms a second welding mark portion 512, and the first welding mark 51 includes the second welding mark portion 512.

[0456] Exemplarily, the second connecting sub-portion 312 is welded to the surface of the transition portion 1222 facing away from the insulating base body 11, and the trace generated by the welding of the transition portion 1222 and the second connecting sub-portion 312 is the second welding mark portion 512.

[0457] In some examples, the first welding mark 51 can only include the second welding mark portion 512, i.e. the first connecting portion 31 is only welded to the transition portion 1222, but not to the protruding portion 1221. In other examples, the first welding mark 51 includes the second welding mark portion 512 and the first welding mark portion 511, and the second welding mark portion 512 is located between the first welding mark portion 511 and the active material layer 20, i.e. the first connecting portion 31 is welded to both the transition portion 1222 and the protruding portion 1221.

[0458] In some examples, the second connecting sub-portion 312 can be integrally welded to the transition portion 1222; alternatively, in other examples, the second connecting sub-portion 312 can also be partially welded to the transition portion 1222 and not welded to the transition portion 1222.

[0459] As an example, the second welding mark portion 512 can be a one-piece structure, or alternatively, the second welding mark portion 512 can also include a plurality of spaced welding points or welding lines.

[0460] The second connecting sub-portion 312 and the transition portion 1222 are connected by welding, which is simple and facilitates the manufacture of the first electrode tab 1. In addition, the second connecting sub-portion 312 and the transition portion 1222 can directly use the second welding mark portion 512 for current flow, which is conducive to improving the current flow capacity between the second connecting sub-portion 312 and the transition portion 1222 and reducing the heat generation of the battery monomer 100.

[0461] In some embodiments, the second insulator portion 42 covers at least part of the second welding portion 512. The second insulator portion 42 can block structures such as burrs, metal debris, etc. on the second welding portion 512, reduce the risk of these structures penetrating through the separator 3 and contacting the second tab 2, and help improve the use reliability of the battery cell 100.

[0462] In some embodiments, along the first direction Z, neither end of the second welding portion 512 exceeds the second insulator portion 42. The embodiments of the application can reduce the exposed area of the second welding portion 512, reduce the risk of the second welding portion 512 piercing the separator 3, and improve the use reliability of the battery cell 100.

[0463] In some embodiments, along the direction in which the first connecting portion 31 points to the active material layer 20, the second insulator portion 42 protrudes from the edge of the second welding portion 512 toward the active material layer 20.

[0464] In some embodiments, along the thickness direction Y of the current collector, the projection of the second welding portion 512 falls within the projection of the first insulator member 4, so that the first insulator member 4 can completely cover the second welding portion 512. The first insulator member 4 can completely cover the second welding portion 512, the first insulator member 4 can block structures such as burrs, metal debris, etc. on the entire second welding portion 512, reduce the risk of these structures penetrating through the separator 3 and contacting the second tab 2, and help improve the use reliability of the battery cell 100.

[0465] In some embodiments, along the second direction X, the size of the transition portion 1222 is L2, the size of the second welding portion 512 is L3, and 0.8≤L3 / L2≤1.

[0466] 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.

[0467] The larger L3 is, the larger the welding area of the transition portion 1222 and the second connecting portion 312 is, and the better the current-carrying capacity of the connection between the transition portion 1222 and the first connecting portion 31 is. The embodiments of the application set L3 / L2 to be 0.8-1, which can make the size of the transition portion 1222 along the second direction X larger, help improve the connection area between the first connecting portion 31 and the transition portion 1222, improve the current-carrying capacity of the connection between the first connecting portion 31 and the transition portion 1222, reduce the heating of the battery cell 100, and improve the fast-charging performance of the battery cell 100.

[0468] In some embodiments, L3=L2. Along the second direction X, the two ends of the second welding portion 512 are flush with the two ends of the transition portion 1222. The embodiments of the present application make the size of the second welding portion 512 along the second direction X larger, which is conducive to designing the welding area between the second connecting sub-portion 312 and the transition portion 1222 to be larger, the overcurrent capacity at the connection between the second connecting sub-portion 312 and the transition portion 1222 is better, which can effectively improve the overcurrent capacity of the first tab 1, reduce the heat generation of the battery monomer 100, and improve the fast-charging performance of the battery monomer 100.

[0469] In other embodiments, L3

[0470] In some embodiments, the protruding portion 1221 and the transition portion 1222 are welded with the first connecting portion 31 at the same time, thereby forming the entire first welding 51, which can effectively increase the welding area between the first connecting portion 31 and the second metal portion 122, improve the overcurrent area between the first connecting portion 31 and the second metal portion 122, and be conducive to improving the overcurrent capacity between the first connecting portion 31 and the second metal portion 122.

[0471] In the process of cutting the conductive member 30, first, cutting is performed on the equal-width welding along the second direction X, then cutting is performed in the direction away from the active material layer 20 until the equal-width welding is left, then cutting is continued in the direction away from the active material layer 20 for a distance, then cutting is continued along the second direction X for a distance, then cutting is performed in the direction toward the active material layer 20 until the equal-width welding is cut for a distance, then cutting is continued on the equal-width welding along the second direction X, and so on, so that the first welding 51 is obtained. Taking the cutting position of cutting on the equal-width welding along the second direction X as a reference, along the first direction Z, the part of the first welding 51 on the side of the cutting position toward the active material layer 20 is the second welding portion 512, and the part on the side of the cutting position away from the active material layer 20 is the first welding portion 511, which can be a protruding structure of the second welding portion 512 away from the active material layer 20; the metal layer 12 of the current collector 10 cuts out the protruding portion 1221 in the process of cutting, and forms the transition portion 1222 between the protruding portion 1221 and the first metal portion 121.

[0472] In some embodiments, the second welding portion 512 and the first welding portion 511 are directly connected.

[0473] In some examples, the second welding portion 512 and the first welding portion 511 form a first welding 51 in one piece, and there is no obvious boundary between the two; the first welding 51 in one piece can cover the junction of the protruding portion 1221 and the transition portion 1222; in the actual manufacturing process, the second welding portion 512 and the first welding portion 511 are formed by cutting the above-mentioned welding with equal width.

[0474] In some examples, the second welding portion 512 and the first welding portion 511 adopt the structure of welding spots, and the welding spot spacing in the second welding portion 512 is the same as the welding spot spacing of the first welding portion 511; for example, the welding spots in the second welding portion 512 and the first welding portion 511 are not welded to the junction line of the protruding portion 1221 and the transition portion 1222, and the spacing between the two adjacent welding spots in the second welding portion 512 and the first welding portion 511 is equal to the welding spot spacing in the second welding portion 512; for example, the welding spots are welded to the junction line of the protruding portion 1221 and the transition portion 1222, thereby connecting the second welding portion 512 and the first welding portion 511 into a whole welding.

[0475] By adopting the technical scheme of this embodiment, the first welding 51 can cover the junction of the protruding portion 1221 and the transition portion 1222, and a part of the current can directly flow to the first connecting portion 31 through the first welding 51 when flowing to the junction of the transition portion 1222 and the protruding portion 1221, thereby reducing the overcurrent pressure at the junction of the protruding portion 1221 and the transition portion 1222, improving the overcurrent capacity of the first tab 1, reducing the heating of the battery monomer 100, and improving the fast charging performance of the battery monomer 100.

[0476] In some embodiments, the end surface of the second connecting sub-portion 312 away from the active material layer 20 is flush with the end surface of the transition portion 1222 away from the first metal portion 121.

[0477] The embodiments of the present application can reduce the redundancy of the second connecting sub-portion 312 or the redundancy of the transition portion 1222, save materials, improve space utilization, and improve the energy density of the battery monomer 100.

[0478] In addition, the first insulating member 4 can simultaneously block the burrs on the end surface of the second connecting sub-portion 312 away from the active material layer 20 and the burrs on the end surface of the transition portion 1222 away from the first metal portion 121, reduce the risk of the burrs piercing the separator 3, and improve the reliability.

[0479] In some embodiments, the number of protrusions 1221 is plural, and the plural protrusions 1221 are arranged at intervals along the second direction X. The first connecting portion 31 includes a second connecting sub-portion 312 and plural first connecting sub-portions 311, the plural first connecting sub-portions 311 are arranged at intervals along the second direction X, and each first connecting sub-portion 311 is welded to a corresponding protrusion 1221 and forms a first welding mark 511. The second connecting sub-portion 312 is arranged continuously along the second direction X, is welded to the transition portion 1222, and forms a second welding mark 512. The first welding mark 51 includes the second welding mark 512 and the plural first welding marks 511.

[0480] For example, the first connecting sub-portion 311 can refer to the portion of the first connecting portion 31 that covers the protrusion 1221, and the second connecting sub-portion 312 can refer to the portion of the first connecting portion 31 that covers the transition portion 1222.

[0481] For example, the second connecting sub-portion 312 is arranged continuously along the second direction X. Alternatively, along the second direction X, the second connecting sub-portion 312 extends from one side of the transition portion 1222 to the other side of the transition portion 1222.

[0482] The plural first connecting sub-portions 311 of the first connecting portion 31 are arranged at intervals along the second direction X, and there is a gap between adjacent two first connecting sub-portions 311, which can reduce the required material of the first connecting portion 31, reduce the manufacturing cost of the battery monomer 100, and improve the energy density of the battery monomer 100.

[0483] The second connecting sub-portion 312 is arranged continuously along the second direction X, which can connect the plural first connecting sub-portions 311 as a whole, and the second connecting sub-portion 312 can provide good support to the first connecting sub-portion 311, which can reduce the risk of the first connecting sub-portion 311 bending into the active material layer 20 and the second electrode plate 2, reduce the risk of short circuit, and be beneficial to improve the use reliability of the battery monomer 100. In addition, along the second direction X, the size of the second connecting sub-portion 312 is large, which is beneficial to increase the welding area between the second connecting sub-portion 312 and the transition portion 1222, improve the overcurrent capacity at the connection between the first connecting portion 31 and the transition portion 1222, improve the overcurrent capacity of the first electrode plate 1, and improve the fast charging performance and use reliability of the battery monomer 100.

[0484] In some embodiments, the number of second connecting portions 32 is plural, and along the first direction Z, one end of the first connecting sub-portion 311 is connected to a corresponding second connecting portion 32, and the other end of the first connecting sub-portion 311 is connected to the corresponding second connecting sub-portion 312.

[0485] In some embodiments, the sum of the sizes L4 of all the first welds 511 is less than the size L3 of the second weld 512, and the size L3 of the second weld 512 is large, which is conducive to increasing the welding area of the transition portion 1222 and the second connecting portion 312, increasing the current carrying capacity of the connection between the transition portion 1222 and the conductive member 30, increasing the current carrying capacity of the first tab 1, reducing the heat generation of the battery monomer 100, and improving the fast charging performance and use reliability of the battery monomer 100.

[0486] In the plurality of first welds 511, the sizes of some of the first welds 511 can be the same along the second direction X, or the sizes of all the first welds 511 can be completely different, or the sizes of all the first welds 511 are the same.

[0487] In some embodiments, the number of metal layers 12 is two, the two metal layers 12 are arranged on opposite sides of the insulating base 11 along the thickness direction Y of the current collector, the number of active material layers 20 is two, and the two active material layers 20 are respectively covered on the two metal layers 12; the number of conductive members 30 is two, and the first connecting portions 31 of the two conductive members 30 are respectively welded to the surfaces of the two metal layers 12 away from the insulating base 11 and form two first welds 51; the number of first insulating components 4 is two, and the two first insulating components 4 respectively cover at least part of the two first welds 51.

[0488] The number of metal layers 12, the number of first insulating components 4, the number of active material layers 20, and the number of conductive members 30 are all two, the two metal layers 12 are respectively covered on opposite sides of the insulating base 11 along the thickness direction Y, and the two active material layers 20 are respectively covered on the first metal portions 121 of the two metal layers 12; the first connecting portion 31 of one conductive member 30 is welded to the surface of one of the metal layers 12 away from the insulating base 11 and forms a first weld 51, the first connecting portion 31 of the other conductive member 30 is welded to the other metal layer 12 and also forms a first weld 51, and the two first insulating components 4 are located on opposite sides of the insulating base 11 along the thickness direction Y and respectively cover the two first welds 51.

[0489] In some embodiments, along the direction in which the first metal portion 121 points to the transition portion 1222, the first insulating component 4 protrudes from the end of the transition portion 1222 away from the first metal portion 121.

[0490] In some embodiments, the first insulating component 4 at least partially covers the end surface of the transition portion 1222 away from the first metal portion 121. Alternatively, the first insulating component 4 completely covers the end surface of the transition portion 1222 away from the first metal portion 121. Along the thickness direction Y of the current collector, the projection of the end surface of the transition portion 1222 away from the first metal portion 121 coincides with the projection of the first insulating component 4.

[0491] Exemplarily, during the cutting of the conductive member 30, burrs are prone to be formed at the transition portion 1222 towards the end face of the protruding portion 1221, especially during the cutting of the conductive member 30 at the first welding mark 51, larger burrs are prone to be formed at the transition portion 1222 towards the end face of the protruding portion 1221. The first insulating member 4 according to the embodiments of the present application can block the burrs at the transition portion 1222 towards the end face of the protruding portion 1221, reduce the risk of the burrs piercing the separator 3 to contact the second tab 2, thereby reducing the risk of short circuit of the battery monomer 100, and facilitating to improve the use reliability of the battery monomer 100.

[0492] In some examples, the transition portion 1222 towards the end face of the protruding portion 1221 is prone to be impacted to generate metal debris, which can fall into the electrode assembly 101, thereby causing the short circuit of the battery monomer 100. The third insulating sub portion 43 of the two first insulating members 4 is arranged in abutment, and the two third insulating sub portions 43 can block the metal debris, reduce the risk of the metal debris falling into the electrode assembly 101, and facilitate to reduce the risk of short circuit.

[0493] In some embodiments, the first welding mark 51 can only include the first welding mark portion 511; exemplarily, in the first direction Z, the interval between the first welding mark portion 511 and the active material layer 20 is 0.3mm-5mm. In other embodiments, the first welding mark 51 can include a second welding mark portion 512, and in the first direction Z, the interval between the second welding mark portion 512 and the active material layer 20 is 0.3mm-5mm.

[0494] In some embodiments, the electrode assembly 101 further includes a second tab 2 opposite in polarity to the first tab 1, the second tab 2 includes a main functional portion 210 and a tab portion 220, the tab portion 220 extends from the end face of the main functional portion 210 along the first direction Z.

[0495] The second tab 2 can refer to a tab opposite in polarity to the first tab 1. For example, the first tab 1 is a positive tab, and the second tab 2 is a negative tab, or the first tab 1 is a negative tab, and the second tab 2 is a positive tab.

[0496] The first tab 1 and the second tab 2 can be laminated and then wound to form a wound electrode assembly 101; alternatively, a plurality of first tabs 1 and a plurality of second tabs 2 are arranged in lamination to form a laminated electrode assembly 101.

[0497] The second tab 2 includes a main functional portion 210 and a tab portion 220. The main functional portion 210 can refer to a main portion of the second tab 2, and the tab portion 220 can refer to a portion of the second tab 2 protruding from the main functional portion 210. For example, in the case where the second tab 2 is a negative tab, the tab portion 220 can refer to a protruding structure at the edge portion of the negative current collector, and the main functional portion 210 can include the negative current collector except the protruding structure and the negative active material layer. For example, in the case where the second tab 2 is a positive tab, the tab portion 220 can refer to a protruding structure at the edge portion of the positive current collector, and the main functional portion 210 can include the positive current collector except the protruding structure and the positive active material layer.

[0498] In some embodiments, along a direction in which the active material layer 20 points to the first connecting portion 31, an end surface of the second connecting sub-portion 312 away from the active material layer 20 exceeds the main functional portion 210.

[0499] Even if the burr on the end surface of the second connecting sub-portion 312 away from the active material layer 20 pierces the separator 3, the burr is less likely to contact the main functional portion 210, thereby reducing the risk of short circuit.

[0500] In some embodiments, along a direction in which the active material layer 20 points to the first connecting portion 31, an end surface of the main functional portion 210 toward the tab portion 220 exceeds the first end surface 31a.

[0501] The main functional portion 210 can exceed the first end surface 31a, so that the main functional portion 210 can have a larger size in the first direction Z, thereby improving the capacity of the main functional portion 210.

[0502] In some embodiments, the first insulating member 4 separates the first end surface 31a from the main functional portion 210, thereby blocking the burr at the first end surface 31a, reducing the possibility of the burr at the first end surface 31a lapping with the main functional portion 210, reducing the risk of short circuit, and improving the reliability of the battery monomer 100.

[0503] In some embodiments, along a direction in which the active material layer 20 points to the first connecting portion 31, the first insulating member 4 exceeds an end surface of the main functional portion 210 toward the tab portion 220.

[0504] For example, along the thickness direction Y of the current collector, a projection of the main functional portion 210 toward the end surface of the tab portion 220 falls within a projection of the first insulating member 4.

[0505] The first insulating member 4 can block the burr at the end surface of the main functional portion 210 of the second tab 2 near the tab portion 220 from piercing the separator 3 and connecting with the first tab 1, reduce the risk of short circuit between the first tab 1 and the second tab 2, and be conducive to improving the use reliability of the battery monomer 100.

[0506] In some embodiments, along the direction of the active material layer 20 pointing to the first connecting part 31, the end face of the main functional part 210 towards the tab part 220 can or can not exceed the end face of the second connecting sub-part 312 facing away from the active material layer 20.

[0507] As an example, in FIG. 6, the connection between the first connecting sub-part 311 and the second connecting sub-part 312 is shown by the dashed line D7, and the connection between the first connecting part 311 and the second connecting part 32 is shown by the dashed line D8.

[0508] Optionally, along the direction of the active material layer 20 pointing to the first connecting part 31, the end face of the main functional part 210 towards the tab part 220 does not exceed the end face of the second connecting sub-part 312 facing away from the active material layer 20. Along the thickness direction Y of the current collector, the projection of the end face of the main functional part 210 towards the tab part 220 at least partially overlaps with the projection of the second connecting sub-part 312. The burr at the end face of the main functional part 210 of the second tab 2 towards the tab part 220 is opposite to the first insulating part 4.

[0509] Alternatively, along the direction of the active material layer 20 pointing to the first connecting part 31, the end face of the main functional part 210 towards the tab part 220 exceeds the end face of the second connecting sub-part 312 facing away from the active material layer 20. Along the thickness direction Y of the current collector, the projection of the end face of the main functional part 210 towards the tab part 220 does not overlap with the projection of the second connecting sub-part 312, so that the burr at the end face of the main functional part 210 of the second tab 2 towards the tab part 220 corresponds to the hollow area of the second metal part 122 not extending out of the protruding part 1221. The burr at the end face of the main functional part 210 of the second tab 2 towards the tab part 220 corresponding to the hollow area of the second metal part 122 not extending out of the protruding part 1221 can also reduce the risk of short circuit of the battery monomer 100 and improve the use reliability of the battery monomer 100.

[0510] In some embodiments, along the thickness direction Y of the current collector, the projection of the second welding mark part 512 can fall within the projection of the main functional part 210, and the second welding mark part 512 can be covered with the first insulating part 4, so that the first insulating part 4 can block burrs, metal debris and other components on the second welding mark part 512, reduce the risk of burrs, metal debris and other components piercing the separator 3 to connect with the second tab 2, reduce the risk of short circuit, and improve the use reliability of the battery monomer 100.

[0511] In some embodiments, the main functional portion 210 protrudes from the end surface of the first insulating member 4 close to the active material layer 20, and does not protrude from the end surface of the first insulating member 4 away from the active material layer 20, in the direction of the active material layer 20 toward the first connecting portion 31.

[0512] FIG. 18 is a partial cross-sectional view of an electrode assembly of a battery cell according to some embodiments of the present application.

[0513] Referring to FIG. 18, in some embodiments, the electrode assembly 101 includes a second insulating member 6 disposed on the surface of the metal layer 12 facing away from the insulating substrate 11. In the first direction Z, at least part of the second insulating member 6 is located between the first connecting portion 31 and the active material layer 20.

[0514] The second insulating member 6 can be, but is not limited to, an insulating coating, an insulating glue (e.g., hot melt glue, etc.), or an insulating adhesive tape.

[0515] In some examples, in the first direction Z, the second insulating member 6 can be located entirely between the first connecting portion 31 and the active material layer 20; alternatively, part of the second insulating member 6 is located between the first connecting portion 31 and the active material layer 20 in the first direction Z, and the other part covers the first connecting portion 31 or the active material layer 20.

[0516] The second insulating member 6 can support the part of the metal layer 12 located between the first connecting portion 31 and the active material layer 20, and can reduce damage such as cracks or fractures of this part during the manufacturing process of the battery device 1100, thereby improving the electronic transmission capability of this part of the metal layer 12 and improving the fast-charging performance and reliability of the battery cell 100. In addition, the second insulating member 6 can also separate the area of the metal layer 12 not covered by the first connecting portion 31 and the active material layer 20 from the second tab 2, thereby reducing the risk of short circuit and improving the reliability of the battery cell 100.

[0517] In some embodiments, in the thickness direction Y of the current collector, the second insulating member 6 is not coincident with the first weld 51, and the second insulating member 6 is arranged to be spaced apart from the first weld 51, so that the first connecting portion 31 is not welded to the second insulating member 6, thereby reducing the risk of false welding between the first connecting portion 31 and the metal layer 12. In other embodiments, the second insulating member 6 is only coincident with the edge of the first weld 51, and the edge of the first weld 51 is coincident with the edge of the second insulating member 6, which can also reduce the risk of false welding between the first connecting portion 31 and the metal layer 12.

[0518] By adopting the technical solutions of the embodiments, the risk of false welding between the first connecting portion 31 and the metal layer 12 can be reduced, the connection reliability of the first connecting portion 31 and the metal layer 12 can be improved, and the overcurrent capacity can be improved.

[0519] In some embodiments, the entire second insulating member 6 is located between the first connecting portion 31 and the active material layer 20 in the first direction Z.

[0520] In some embodiments, a portion of the first insulating member 4 is located on the side of the second insulating member 6 away from the metal layer 12 and is connected to the second insulating member 6.

[0521] The first insulating member 4 can cover a portion of the second insulating member 6 or completely cover the second insulating member 6. For example, the second insulating member 6 extends to the active material layer 20 in the first direction Z, thereby completely covering the second insulating member 6.

[0522] For example, the portion of the first insulating member 4 covering the second insulating member 6 is connected to the portion of the first insulating member 4 covering the first connecting portion 31.

[0523] Connecting the first insulating member 4 to the second insulating member 6 can reduce the risk of the first insulating member 4 falling off. The first insulating member 4 and the second insulating member 6 can jointly cover the metal layer 12, thereby improving the insulation effect, reducing the risk of the metal layer 12 being in conduction with the second electrode tab 2, and improving the reliability.

[0524] In some embodiments, the two ends of the second insulating member 6 in the first direction Z are connected to the active material layer 20 and the first connecting portion 31, respectively.

[0525] In some embodiments, a portion of the first insulating member 4 covers the first connecting portion 31, and another portion of the first insulating member 4 covers the active material layer 20. The first insulating member 4 is continuously arranged in the first direction Z and covers the portion of the metal layer 12 between the first connecting portion 31 and the active material layer 20.

[0526] The first insulating member 4 and the metal layer 12 can be provided with the second insulating member 6 or can not be provided with the second insulating member 6.

[0527] In some examples, the metal layer 12 is covered with the second insulating member 6, and the first insulating member 4 completely covering the second insulating member 6 can further extend onto the active material layer 20 to cover a portion of the active material layer 20. The metal layer 12 is covered with the second insulating member 6 and the first insulating member 4, achieving two-layer insulation and good insulation effect.

[0528] In some examples, the metal layer 12 is not covered by the second insulating member 6, and the first insulating member 4 extends from the first connecting part 31 to the active material layer 20, so as to cover the part of the metal layer 12 between the first connecting part 31 and the active material layer 20, reduce the risk of short circuit of this part, and improve the use reliability of the battery monomer 100. In addition, the second insulating member 6 can be omitted to save cost, and the active material layer 20 can be used to cover the position of the original second insulating member 6, so as to increase the coverage area of the active material layer 20 on the metal layer 12, and improve the energy density of the battery monomer 100.

[0529] The first insulating member 4 extends from the first connecting part 31 to the active material layer 20, the coverage area of the first insulating member 4 is wide, and the insulation effect is good, which is conducive to improving the use reliability of the battery monomer 100.

[0530] In some examples, the second insulating member 6 is connected to the end surface of the active material layer 20 facing the first connecting part 31. The second insulating member 6 and the active material layer 20 form a mutual solubility region, so that the fixation of the second insulating member 6 is more stable.

[0531] In some examples, the second insulating member 6 is connected to a part of the active material layer 20 facing the first connecting part 31.

[0532] In some examples, the second insulating member 6 is arranged on the transition part. Optionally, the second insulating member 6 is coated on the transition part.

[0533] FIG. 19 is a schematic view of the first pole piece, the first insulating member and the second insulating member of the battery monomer in an unfolded state according to some examples of the present application; FIG. 20 is a sectional view of FIG. 19 taken along line D-D; FIG. 21 is a schematic view of the first pole piece and the second insulating member shown in FIG. 19; FIG. 22 is an enlarged schematic view of the circle frame in FIG. 21;

[0534] FIG. 23 is a schematic view of the first pole piece shown in FIG. 21, in which the conductive member is shown; FIG. 24 is an enlarged schematic view of the circle frame in FIG. 23; FIG. 25 is a schematic view of the first insulating member shown in FIG. 19; FIG. 26 is an enlarged schematic view of the circle frame in FIG. 25; FIG. 27 is a schematic view of a part of the conductive member shown in FIG. 21.

[0535] Referring to FIGS. 19-27, in some examples, the second metal part 122 includes at least one protruding part 1221; the first connecting part 31 includes at least one first connecting sub-part 311, the first connecting sub-part 311 is located on the side of the protruding part 1221 away from the insulating base 11, and the first connecting sub-part 311 corresponds to the protruding part 1221 one by one.

[0536] Optionally, the first connecting portion 31 can include only the first connecting sub-portion 311 overlapping the protruding portion 1221. In other words, the first connecting portion 31 can not include the second connecting sub-portion 312. The second metal portion 122 can include the transition portion 1222 or can not include the transition portion 1222.

[0537] In some embodiments, the second metal portion 122 includes one protruding portion 1221, and the first connecting portion 31 includes one first connecting sub-portion 311. The first connecting sub-portion 311 faces the first end surface 31a of the active material layer 20.

[0538] In some embodiments, the second metal portion 122 includes a plurality of protruding portions 1221, and the first connecting portion 31 includes a plurality of first connecting sub-portions 311. The plurality of first connecting sub-portions 311 and the plurality of protruding portions 1221 are arranged one-to-one. Each first connecting sub-portion 311 has a second end surface 31b facing one end of the active material layer 20. The second end surfaces 31b of the plurality of first connecting sub-portions 311 form the first end surface 31a.

[0539] The first insulating member 4 can block the burr at each second end surface 31b, reduce the possibility of the burr at the second end surface 31b piercing the separator 3 and contacting the second electrode tab 2, and thus reduce the risk of short circuit.

[0540] In some embodiments, the conductive member 30 includes a plurality of second connecting portions 32. Each first connecting sub-portion 311 is connected to each second connecting portion 32 one-to-one. For example, one first connecting portion 31 and one second connecting portion 32 form one conductive tab, and the conductive member 30 includes a plurality of conductive tabs arranged in the second direction X. For example, the plurality of conductive tabs of two conductive members 30 are arranged one-to-one. For example, in FIG. 17, the boundary between the first connecting sub-portion 311 and the second connecting portion 32 is shown by a dashed line. The boundary between the first connecting sub-portion 311 and the second connecting portion 32 corresponds to the end surface of the protruding portion 1221 facing away from the transition portion.

[0541] In some embodiments, the first connecting sub-portion 311 covers only a portion of the protruding portion 1221. For example, in the direction of the first connecting portion 31 pointing to the active material layer 20, the protruding portion 1221 protrudes from the second end surface 31b.

[0542] In some embodiments, the first insulating member 4 covers the portion of the protruding portion 1221 that is not covered by the first connecting sub-portion 311.

[0543] In some embodiments, the electrode assembly 101 includes a second insulating member 6, at least a portion of the second insulating member 6 is disposed on the protrusion 1221 and between the first connecting sub-member 311 and the active material layer 20. Alternatively, the second insulating member 6 can be omitted, and a portion of the first insulating member 4 is attached to the first connecting sub-member 311, and another portion of the first insulating member 4 is attached to the protrusion 1221.

[0544] In some embodiments, the first insulating member 4 completely covers the first connecting sub-member 311.

[0545] In some embodiments, the first insulating member 4 completely covers the protrusion 1221.

[0546] In some embodiments, the second metal member 122 further includes a transition member 1222, the transition member 1222 is connected between the first metal member 121 and the protrusion 1221.

[0547] In some embodiments, the first insulating member 4 covers at least a portion of the transition member 1222.

[0548] In some embodiments, the first insulating member 4 protrudes from an end surface of the transition member 1222 facing away from the first metal member 121 in a direction pointing from the first metal member 121 to the transition member 1222. The first insulating member 4 can block burrs at the end surface of the transition member 1222, reducing the risk of the burrs piercing the separator 3 and contacting the second electrode tab 2, thereby reducing the risk of short circuit and improving reliability.

[0549] In some embodiments, the first insulating member 4 completely covers the transition member 1222.

[0550] In some embodiments, the electrode assembly 101 includes a second insulating member 6, at least a portion of the second insulating member 6 is disposed on the transition member 1222.

[0551] Optionally, the first insulating member 4 covers the second insulating member 6.

[0552] In some embodiments, the first insulating member 4 includes a first insulating sub-member 41, a second insulating sub-member 42, a third insulating sub-member 43, and a fourth insulating sub-member 44.

[0553] The first insulating sub-member 41 covers a surface of the first connecting sub-member 311 facing away from the protrusion 1221. The second insulating sub-member 42 is connected to the first insulating sub-member 41 and is located on a side of the first insulating sub-member 41 facing the active material layer 20 in the first direction Z.

[0554] The third insulator portion 43 and the first insulator portion 41 are disposed along the second direction X; in the first direction Z, the third insulator portion 43 and the first insulator portion 41 are located on the same side of the second insulator portion 42. The end of the third insulator portion 43 along the first direction Z is connected to the second insulator portion 42, and the end of the third insulator portion 43 along the second direction X is connected to the first insulator portion 41.

[0555] The fourth insulator portion 44 is connected to the first insulator portion 41, and the second insulator portion 42 is located on the side of the first insulator portion 41 facing away from the active material layer 20 along the first direction Z. Optionally, the fourth insulator portion 44 is attached to the second connecting portion 32 and connected to the third insulator portion 43.

[0556] As an example, referring to Figures 25 and 26, the boundary lines of the first insulating part, the second insulating part, the third insulating part, and the fourth insulating part are represented by dashed lines D9 and D1. 10 D 11 D 12 D 13 D 14 As shown. The dashed line D9 corresponds to the second end face 31b (the intersection of the plane containing the second end face 31b and the first insulating component 4 is the dashed line D9). 10 Corresponding to the junction of the first connecting portion 31 and the second connecting portion 32 (the junction of the first connecting portion 31 and the second connecting portion 32 corresponds to the end face of the protrusion 1221 facing away from the transition portion 1222), D 11 and D 12 Corresponding to the two ends of the first connecting sub-part 311 along the second direction X, D 13 and D 14 They correspond to the two ends of the second connecting part 32 along the second direction X, respectively.

[0557] In some embodiments, there are multiple third insulator portions 43 and multiple first insulator portions 41, and the multiple third insulator portions 43 and multiple first insulator portions 41 are alternately arranged along the second direction X.

[0558] In some embodiments, the third insulator portion 43 can block burrs at the end of the first connector portion 311 along the second direction X and burrs at the end of the second connector portion 32 along the second direction X.

[0559] In some embodiments, along the direction from the transition portion 1222 to the first metal portion 121, the second insulator portion 42 protrudes from the end face of the transition portion 1222 facing the protrusion 1221. The second insulator portion 42 can block burrs on the end face of the transition portion 1222 facing the protrusion 1221.

[0560] In some embodiments, along the second direction X, the two ends of the second insulating sub-portion 42 protrude from the two ends of the transition portion 1222 respectively.

[0561] In some embodiments, the protruding portion 1221 comprises a first protruding sub-portion 1221a and a second protruding sub-portion 1221b, the first protruding sub-portion 1221a is connected between the second protruding sub-portion 1221b and the first metal portion 121. Along the second direction X, the size l1 of the first protruding sub-portion 1221a is greater than the size l2 of the second protruding sub-portion 1221b.

[0562] For example, the protruding portion 1221 has a stepped structure, along the first direction Z, the protruding portion 1221 is divided into two parts, the part close to the first metal portion 121 is the first protruding sub-portion 1221a, and the part away from the first metal portion 121 is the second protruding sub-portion 1221b; along the second direction X, the size of the first protruding sub-portion 1221a is greater than the size of the second protruding sub-portion 1221b, which is equivalent to increasing the size of the first protruding sub-portion 1221a along the second direction X, improving the flow area between the protruding portion 1221 and the first metal portion 121, improving the flow capacity, and reducing the heat generation of the battery monomer 100.

[0563] The first protruding sub-portion 1221a can refer to the root of the protruding portion 1221 close to the transition portion 1222; for example, along the second direction X, the size l1 of the first protruding sub-portion 1221a can refer to the length of the boundary line (see dashed line D 15 ) between the protruding portion 1221 and the transition portion 1222. The size l1 of each first protruding sub-portion 1221a along the second direction X can be the same or different.

[0564] Along the second direction X, the size l2 of the second protruding sub-portion 1221b is equal to the length of the boundary line (see dashed line D 16 ) between the first protruding sub-portion 1221a and the second protruding sub-portion 1221b. The size l2 of each second protruding sub-portion 1221b along the second direction X can be the same or different.

[0565] l1>l2, which is equivalent to increasing the size of the first protruding sub-portion 1221a along the second direction X, increasing the flow area between the protruding portion 1221 and the transition portion 1222, improving the flow capacity, and reducing the heat generation of the battery monomer 100.

[0566] In some embodiments, the first connecting sub-portion 311 comprises a first connecting protruding portion 3111, and the first connecting protruding portion 3111 is located on the side of the first protruding sub-portion 1221a away from the insulating base body 11.

[0567] The first insulating component 4 comprises at least one first insulating sub-portion 41 corresponding to the first connecting sub-portion 311 one by one, and at least part of the first insulating sub-portion 41 covers the first connecting protruding portion 3111. The first insulating sub-portion 41 can cover the first connecting protruding portion 3111, reducing the risk of the first connecting protruding portion 3111 contacting and conducting with the second pole piece 2.

[0568] In some embodiments, the first connecting protruding portion 3111 is welded to the surface of the first protruding sub-portion 1221a away from the insulating base body 11 and forms a first welding mark sub-portion 5111, and the first welding mark portion 511 comprises the first welding mark sub-portion 5111.

[0569] Exemplarily, the first connecting protruding portion 3111 is welded to the surface of the first protruding sub-portion 1221a away from the insulating base body 11, and the trace generated by welding can be the first welding mark sub-portion 5111.

[0570] Exemplarily, the first connecting protruding portion 3111 can be welded to the first protruding sub-portion 1221a to reduce the distance between the first welding mark sub-portion 5111 and the transition portion 1222, thereby facilitating to improve the flow capacity between the first connecting portion 31 and the transition portion 1222, reduce the heat generation of the battery monomer 100, and improve the fast charging performance and use reliability of the battery monomer 100.

[0571] In some embodiments, the first insulating sub-portion 41 covers at least part of the first welding mark sub-portion 5111. The first insulating sub-portion 41 can cover part of the first welding mark sub-portion 5111, or cover the entire first welding mark sub-portion 5111.

[0572] The first connecting protruding portion 3111 is welded to the first protruding sub-portion 1221a and forms the first welding mark sub-portion 5111, and the first protruding sub-portion 1221a has a large size in the second direction X, which facilitates to increase the welding area of the protruding portion 1221 and the first connecting sub-portion 311, improve the flow area between the protruding portion 1221 and the first connecting sub-portion 311, improve the flow capacity, reduce the heat generation of the battery monomer 100, and improve the fast charging performance and use reliability of the battery monomer 100. In addition, in the second direction X, the second protruding sub-portion 1221b has a small size, which facilitates to reduce the occupied space of the protruding portion 1221 and improve the energy density of the battery monomer 100. The first insulating component 4 can block burrs, metal debris and other components on the first welding mark sub-portion 5111, reduce the risk of burrs, metal debris and other components passing through the isolation piece 3 and contacting the second pole piece 2, and facilitate to improve the use reliability of the battery monomer 100.

[0573] In some embodiments, along the second direction X, the sum l3 of the sizes of the first protruding sub-portion 1221a of all the protruding portions 1221 is greater than 0.5 times the size L1 of the first metal portion 121, and exemplarily, 0.5≤l3 / L1≤1.

[0574] Along the second direction X, the sum of the sizes l3 of the first protruding sub-parts 1221a of all the protruding parts 1221 is greater than or equal to more than half of the size L1 of the first metal part 121, which increases the total flow area between the protruding parts 1221 and the first metal part 121 and improves the total flow capacity between the protruding parts 1221 and the first metal part 121; for example, the sum of the sizes l3 of the first protruding sub-parts 1221a of all the protruding parts 1221 along the second direction X can be increased by increasing the number of the protruding parts 1221, or the sum of the sizes l3 of the first protruding sub-parts 1221a of all the protruding parts 1221 along the second direction X can be increased by increasing the size of a single first protruding sub-part 1221a along the second direction X.

[0575] In some examples, the value of l3 / L1 can be 0.5 and any value between 0.5 and 1, for example; wherein the value of l3 / L1 can be but is not limited to 0.5, 0.6, 0.7, 0.8, 0.9, 0.99.

[0576] In some embodiments, along the direction in which the first metal part 121 points to the protruding part 1221, the first insulating part 4 protrudes from the end face of the first protruding sub-part 1221a which faces away from the first metal part 121.

[0577] Along the thickness direction Y of the current collector, the projection of the end face of the first protruding sub-part 1221a which faces away from the first metal part 121 falls within the projection of the first insulating part 4.

[0578] During the manufacturing process of the pole piece, the end face of the first protruding sub-part 1221a which faces away from the first metal part 121 is obtained by cutting, which causes burrs to be easily generated at the end face of the first protruding sub-part 1221a which faces away from the first metal part 121, and the first insulating part 4 can block the burrs at the end face of the first protruding sub-part 1221a which faces away from the first metal part 121, thereby reducing the risk of short circuit inside the battery monomer 100 and being beneficial to improve the use reliability of the battery monomer 100; in addition, the first insulating part 4 can completely cover the first solder sub-part 5111, thereby reducing the risk of short circuit caused by burrs, metal debris and other components on the first solder sub-part 5111, and being beneficial to improve the use reliability of the battery monomer 100.

[0579] In some embodiments, along the second direction X, the first solder sub-part 5111 extends from one side edge of the first protruding sub-part 1221a to the other side edge of the first protruding sub-part 1221a.

[0580] Along the thickness direction Y, the projection of the first solder sub-part 5111 falls within the projection of the first protruding sub-part 1221a.

[0581] The first welding sub-part 5111 has a large size along the second direction X, which is beneficial to increase the welding area of the protruding part 1221 and the first connecting part 31, increase the flow area between the protruding part 1221 and the first metal part 121, improve the flow capacity, reduce the heat generation of the battery monomer 100, and improve the fast charging performance and use reliability of the battery monomer 100.

[0582] In some embodiments, the first connecting sub-part 311 includes a second connecting protruding part 3112 located on the side of the second protruding sub-part 1221b away from the insulating base 11. Along the second direction X, the size of the first connecting protruding part 3111 is larger than the size of the second connecting protruding part 3112.

[0583] As an example, the junction of the second connecting protruding part 3112 and the first connecting protruding part 3111 corresponds to the junction of the first protruding sub-part 1221a and the second protruding sub-part 1221b. For example, in FIG. 27, the junction of the second connecting protruding part 3112 and the first connecting protruding part 3111 is indicated by a dashed line D 17 . The junction of the second connecting protruding part 3112 and the second connecting part 32 is indicated by a dashed line D 18 .

[0584] The first insulating sub-part 41 covers the first connecting protruding part 3111 and the second connecting protruding part 3112. The first insulating sub-part 41 can cover the first connecting protruding part 3111 and the second connecting protruding part 3112, reducing the risk of contact and conduction between the first connecting sub-part 311 and the second pole piece 2.

[0585] In some embodiments, the first welding part 511 further includes a second welding sub-part 5112, the second connecting protruding part 3112 is welded to the surface of the second protruding sub-part 1221b away from the insulating base 11 and forms the second welding sub-part 5112, and the first insulating part 4 covers at least part of the second welding sub-part 5112.

[0586] As an example, the surface of the second protruding sub-part 1221b away from the insulating base 11 is welded to the second connecting protruding part 3112, and the trace generated by the welding is the second welding sub-part 5112.

[0587] The first insulating sub-part 41 can cover part of the second welding sub-part 5112, or cover the entire second welding sub-part 5112.

[0588] The second protruding sub-part 1221b is also welded with the first connecting sub-part 311, which is conducive to increasing the flow area between the first connecting sub-part 311 and the protruding part 1221 and improving the flow capacity between the first connecting sub-part 311 and the protruding part 1221. The first insulating part 4 can block burrs, metal chips and other components on the second welding sub-part 5112, reduce the risk of burrs, metal chips and other components passing through the separator 3 and contacting the second pole piece 2, and is conducive to improving the use reliability of the battery monomer 100.

[0589] In some embodiments, along the direction of the first metal part 121 pointing to the protruding part 1221, the first insulating part 4 protrudes from the edge of the second welding sub-part 5112 away from the first protruding sub-part 1221a.

[0590] Along the thickness direction Y of the current collector, the projection of the edge of the second welding sub-part 5112 away from the first protruding sub-part 1221a falls within the projection of the first insulating part 4, so that the first insulating part 4 can completely cover the second welding sub-part 5112 and the first welding sub-part 5111.

[0591] The first insulating part 4 can completely cover the second welding sub-part 5112 and the first welding sub-part 5111, reduce the risk of short circuit caused by burrs, metal chips and other components on the second welding sub-part 5112 and the first welding sub-part 5111, and is conducive to improving the use reliability of the battery monomer 100.

[0592] In some embodiments, along the second direction X, the second welding sub-part 5112 extends from one side edge of the second protruding sub-part 1221b to the other side edge of the second protruding sub-part 1221b.

[0593] Along the thickness direction Y, the projection of the second welding sub-part 5112 falls within the projection of the second protruding sub-part 1221b.

[0594] The second welding sub-part 5112 has a large size along the second direction X, which is conducive to increasing the welding area between the first connecting sub-part 311 and the protruding part 1221, and improving the flow area and flow capacity between the first connecting sub-part 311 and the protruding part 1221.

[0595] FIG. 28 is a schematic view of a first pole piece, a first insulating part and a second insulating part of a battery monomer in an unfolded state according to some embodiments of the present application; and FIG. 29 is a schematic view of a partial structure of the first insulating part shown in FIG. 28.

[0596] Referring to FIGS. 28 and 29, in some embodiments, the first insulating component 4 further comprises a plurality of second insulating subparts 42, the plurality of first insulating subparts 41 and the plurality of second insulating subparts 42 are arranged one-to-one corresponding, and the first insulating subpart 41 is connected with the corresponding second insulating subpart 42. The first direction Z, the second insulating subpart 42 is located on the side of the first insulating subpart 41 facing the active material layer 20. By arranging the second insulating subpart 42 in multiple, the size of a single second insulating subpart 42 can be reduced, the space can be saved, and the energy density can be improved.

[0597] In some embodiments, along the second direction X, the size of the second insulating subpart 42 is greater than or equal to the size of the first insulating subpart 41.

[0598] In some embodiments, along the second direction X, two third insulating subparts 43 are arranged between two adjacent first insulating subparts 41.

[0599] The two third insulating subparts 43 located between the two adjacent first insulating subparts 41 are respectively connected with the two first insulating subparts 41. The first insulating component 4 forms a hollow area between the two third insulating subparts 43, thereby saving the weight and space occupied by the first insulating component 4 and improving the energy density.

[0600] In some embodiments, the number of third insulating subparts 43 is twice the number of first insulating subparts 41.

[0601] In some embodiments, the first insulating component 4 comprises a plurality of insulating sheets 40, and the plurality of insulating sheets 40 are arranged one-to-one corresponding with a plurality of conductive sheets. The conductive sheet is composed of a first connecting subpart 311 and a second connecting part 32, and the insulating sheet 40 is composed of a first insulating subpart 41, a second insulating subpart 42, two third insulating subparts 43 and a fourth insulating subpart 44.

[0602] As an example, in FIG. 29, the junction lines of the first, second, third and fourth insulating parts are shown by dashed lines D9, D 10 , D 11 , D 12 , D 13 , D 14 , and D 10 . Among them, the dashed line D9 corresponds to the second end surface 31b (the intersection line of the plane where the second end surface 31b is located and the first insulating component 4 can be the dashed line D9), the dashed line D 11 corresponds to the junction of the first connecting part 31 and the second connecting part 32 (the junction of the first connecting part 31 and the second connecting part 32 corresponds to the end surface of the protruding part 1221 facing away from the transition part 1222), D 12 and D 13and D 14 respectively correspond to the two ends of the second connection portion 32 along the second direction X.

[0603] In some embodiments, the insulating sheet 40 completely covers the corresponding conductive sheet.

[0604] In some embodiments, the insulating sheet 40 can be a rectangular adhesive tape.

[0605] FIG. 30 is a schematic view of a first electrode sheet and a first insulating component of a battery cell in an unfolded state according to some embodiments of the present application; FIG. 31 is a schematic view of the first electrode sheet shown in FIG. 30; and FIG. 32 is another schematic view of the first electrode sheet shown in FIG. 31, with the conductive member omitted.

[0606] Referring to FIGS. 30 to 32, in some embodiments, the second metal portion 122 includes a transition portion 1222, both ends of the transition portion 1222 in the second direction X are flush with both ends of the first metal portion 121, and the second direction X is perpendicular to the first direction Z and the thickness direction Y of the current collector.

[0607] As an example, the second metal portion 122 can include a protruding portion or can not include a protruding portion.

[0608] Alternatively, the second metal portion 122 does not include a protruding portion.

[0609] The size of the transition portion 1222 along the second direction X is the same as the size of the first metal portion 121 along the second direction X, and the current of the first metal portion 121 can be uniformly transmitted to the transition portion 1222, thereby improving current uniformity, improving overcurrent capacity, and improving the fast charging performance of the battery cell 100.

[0610] In some embodiments, the first connection portion 31 includes a second connection sub-portion 312, the second connection sub-portion 312 is located on the side of the transition portion 1222 away from the insulating substrate 11, the second connection sub-portion 312 is welded to the surface of the transition portion 1222 away from the insulating substrate 11 and forms a second welding mark portion 512, and the first welding mark 51 includes the second welding mark portion 512. The end surface of the second connection sub-portion 312 facing the active material layer 20 is the first end surface 31a.

[0611] In the cycle process of the battery cell 100, the current can be transmitted between the transition portion 1222 and the second connection sub-portion 312, thereby improving the overcurrent capacity and improving the fast charging performance and use reliability of the battery cell 100. The first insulating component 4 can block the burr at the first end surface 31a, reduce the possibility of the burr piercing the separator 3 and contacting the second electrode sheet 2, and thereby reduce the risk of short circuit.

[0612] In some embodiments, in the second direction X, both ends of the first insulating member 4 protrude from the second connecting sub-member 312. The first insulating member 4 can block burrs at both ends of the second connecting sub-member 312 in the second direction X, reduce the possibility of the burrs piercing the separator 3 and contacting the second tab 2, and thus reduce the risk of short circuit.

[0613] In some embodiments, the first insulating member 4 completely covers the transition portion 1222 and the second connecting sub-member 312.

[0614] In some embodiments, the second connecting portion 32 is connected to an end of the second connecting sub-member 312 away from the active material layer 20.

[0615] In some embodiments, the second connecting portion 32 is multiple. The second connecting sub-member 312 continuously extends in the second direction X and is connected to multiple second connecting portions 32.

[0616] In some embodiments, in the direction of the active material layer 20 pointing to the first connecting portion 31, the first insulating member 4 protrudes from the end surface of the second connecting sub-member 312 away from the active material layer 20.

[0617] In some embodiments, in the direction of the active material layer 20 pointing to the first connecting portion 31, the end surface of the second connecting sub-member 312 away from the active material layer 20 can protrude beyond the end surface of the transition portion 1222 away from the first metal portion 121, or can be flush with the end surface of the transition portion 1222 away from the first metal portion 121.

[0618] FIG. 33 is a partial cross-sectional schematic view of an electrode assembly of a battery cell according to some embodiments of the present application.

[0619] Referring to FIG. 33, in some embodiments, the current collector 10 includes two metal layers 12 arranged on opposite sides of the insulating base 11 in the thickness direction Y of the current collector. The first tab 1 includes two active material layers 20 arranged on the two metal layers 12, respectively, and two conductive members 30 having first connecting portions 31 welded to second metal portions 122 of the two metal layers 12 and forming two first welds 51, respectively. Second connecting portions 32 of the two conductive members 30 are welded and form a second weld 52.

[0620] In some embodiments, the first insulating member 4 covers at least part of the second weld 52.

[0621] The first insulating member 4 can cover part of the second weld 52, or can cover the entire second weld 52.

[0622] The first insulating component 4 can block the burrs, metal scraps and the like on the second welding mark 52, reduce the risk of the burrs, metal scraps and the like piercing the separator 3 and contacting the second tab 2, reduce the short circuit risk, and improve the use reliability of the battery monomer 100.

[0623] In some embodiments, the first insulating component 4 protrudes from the edge of the active material layer 20 away from the second welding mark 52 in the direction pointing to the first connecting portion 31 along the active material layer 20.

[0624] The first insulating component 4 can completely cover the second welding mark 52 to block the burrs, metal scraps and the like on the entire second welding mark 52, reduce the risk of the burrs, metal scraps and the like piercing the separator 3 and contacting the second tab 2, reduce the short circuit risk, and improve the use reliability of the battery monomer 100.

[0625] FIG. 34 is a partial cross-sectional view of an electrode assembly of a battery monomer according to some embodiments of the present application; FIG. 35 is a schematic view of a first tab of a battery monomer in a flattened state according to some embodiments of the present application, in which the conductive member is omitted; and FIG. 36 is an enlarged view of the circular frame portion of FIG. 35.

[0626] Referring to FIGS. 34 to 36, in some embodiments, the current collector 10 further includes a conductive protective layer 13, at least a portion of which is located between the active material layer 20 and the metal layer 12.

[0627] The conductive protective layer 13 can refer to a conductive structure provided between the active material layer 20 and the metal layer 12, which can conduct electricity so that the battery monomer 100 can output or input electric energy. The conductive protective layer 13 can be an equal-thickness structure or a non-equal-thickness structure.

[0628] For example, a portion of the conductive protective layer 13 is located between the active material layer 20 and the first metal portion 121, and another portion covers the transition portion 1222 and protrudes out of the active material layer 20.

[0629] For example, the entire conductive protective layer 13 is located between the active material layer 20 and the first metal portion 121.

[0630] In some examples, the conductive protective layer 13 can contain conductive carbon black and a binder, which on the one hand plays a buffering and lubricating role between the active material and the metal layer 12, and can alleviate the damage of the particles in the active material layer 20 to the metal layer 12 during the rolling process of the first tab 1; on the other hand, the conductive carbon black can reduce the contact resistance between the particles and the metal layer 12, which is conducive to improving the use performance of the battery monomer 100.

[0631] During the rolling process of the first pole piece 1, the thickness of the metal layer 12 is thin, and the particles in the active material layer 20 can damage the metal layer 12, thereby causing the metal layer 12 to be prone to cracks and other problems. The conductive protective layer 13 of the embodiment of the application can separate the active material layer 20 and the metal layer 12 while protecting the metal layer 12, reducing the risk of cracks in the metal layer 12 caused by rolling the active material layer 20, and being conducive to improving the overcurrent capacity of the metal layer 12.

[0632] In some embodiments, in the direction in which the active material layer 20 points to the first connecting part 31, the conductive protective layer 13 protrudes from the end face of the active material layer 20 towards the first connecting part 31.

[0633] The conductive protective layer 13 protrudes from the active material layer 20, and the conductive protective layer 13 can completely separate the metal layer 12 and the active material layer 20. In addition, it can also provide an extension space for the active material layer 20 during the rolling process, which is conducive to the subsequent conductive protective layer 13 being able to completely separate the metal layer 12 and the active material layer 20.

[0634] By adopting the technical scheme of this embodiment, the conductive protective layer 13 can completely separate the active material layer 20 and the metal layer 12, the protective ability of the conductive protective layer 13 to the metal layer 12 is better, and the overcurrent capacity of the first pole piece 1 is better, which is conducive to improving the fast charging performance and use reliability of the battery monomer 100.

[0635] In some embodiments of the present application, in the direction in which the active material layer 20 points to the first connecting part 31, the protruding length of the end face of the conductive protective layer 13 protruding from the active material layer 20 towards the first connecting part 31 is S3, and 0.3mm≤S3≤0.8mm.

[0636] The value of S3 can be 0.3mm, 0.8mm and any value between 0.3mm and 0.8mm, for example: the value of S3 can be but not limited to 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm.

[0637] The design of S3≥0.3mm can make the conductive protective layer 13 completely separate the active material layer 20 and the metal layer 12, the protective ability of the conductive protective layer 13 to the metal layer 12 is better, and the overcurrent capacity of the first pole piece 1 is better, which is conducive to improving the fast charging performance and use reliability of the battery monomer 100; the design of S3≤0.8mm makes the conductive protective layer 13 not too large, which is conducive to saving the internal space of the battery monomer 100 and improving the energy density of the battery monomer 100.

[0638] By adopting the technical scheme of this embodiment, the overcurrent capacity and energy density of the battery monomer 100 can be better balanced.

[0639] In some embodiments, the current collector 10 further comprises an electrically conductive protective layer 13, at least part of the electrically conductive protective layer 13 is located between the active material layer 20 and the metal layer 12, and the electrically conductive protective layer 13 is spaced apart from the first welding mark 51 along the first direction Z. The first connecting part 31 is not welded to the electrically conductive protective layer 13, which can reduce the risk of false welding and the like, and is conducive to improving the reliability of the welding of the first connecting part 31 to the metal layer 12.

[0640] In some embodiments, the electrically conductive protective layer 13 is spaced apart from the first connecting part 31 along the first direction Z. The embodiments of the present application can reduce the possibility of the first connecting part 31 overlapping the electrically conductive protective layer 13, reduce the interference of the electrically conductive protective layer 13 with the connection of the first connecting part 31 to the metal layer 12, and improve the connection strength and overcurrent capacity between the first connecting part 31 and the metal layer 12.

[0641] In some embodiments, at least one of the first insulating component 4 and the second insulating component 6 covers the part of the electrically conductive protective layer 13 located between the first connecting part 31 and the active material layer 20.

[0642] The metal layer 12 comprises a first metal part 121 and a second metal part 122 arranged and connected along the first direction Z, the first metal part 121 is covered with the active material layer 20, and the second metal part 122 is not covered with the active material layer 20. The second metal part 122 comprises a transition part 1222 and at least one protruding part 1221; the transition part 1222 is connected between the first metal part 121 and the protruding part 1221. Along the second direction X, the size of the transition part 1222 is greater than the sum of the sizes of all the protruding parts 1221, and the second direction X is perpendicular to the first direction Z and the thickness direction Y of the current collector. The first connecting part 31 is welded to the second metal part 122 and forms the first welding mark 51.

[0643] In some embodiments, the thickness of the first metal part 121 is at least partially less than the thickness of the transition part 1222.

[0644] For example, the transition part 1222 is an equal-thickness structure or a substantially equal-thickness structure, the first metal part 121 is also an equal-thickness structure or a substantially equal-thickness structure, and the thickness t1 of the transition part 1222 is greater than the thickness of the first metal part 121.

[0645] For example, the first metal part 121 can be of unequal thickness, and the thickness of the first metal part 121 increases along the direction of the first metal part 121 pointing to the protruding part 1221, which can be a stepped increase or a slow increase, and the thickness of the part of the first metal part 121 away from the transition part 1222 is less than the thickness of the transition part 1222.

[0646] The thickness t1 of the transition portion 1222 is large, the flow capacity of the transition portion 1222 is good, the flow capacity of the first pole piece 1 is improved, the heat generation of the battery monomer 100 is reduced, and the fast charging performance and use reliability of the battery monomer 100 are improved.

[0647] In some embodiments, the first metal portion 121 includes a first sub-portion 1211 and a second sub-portion 1212, the first sub-portion 1211 is connected between the second sub-portion 1212 and the transition portion 1222, the first sub-portion 1211 and the second sub-portion 1212 are covered with the active material layer 20, the thickness of the first sub-portion 1211 is greater than the thickness of the second sub-portion 1212, and the thickness of the transition portion 1222 is greater than or equal to the thickness of the first sub-portion 1211.

[0648] The first metal portion 121 can be of unequal thickness structure, along the direction of the first metal portion 121 pointing to the protruding portion 1221, the first metal portion 121 is divided into two parts, the part close to the transition portion 1222 is the first sub-portion 1211, and the part away from the transition portion 1222 is the second sub-portion 1212, and the first sub-portion 1211 and the second sub-portion 1212 are both covered with the active material layer 20.

[0649] In some examples, the first sub-portion 1211 can be of equal thickness structure, and the second sub-portion 1212 can be of equal thickness structure; the thickness t2 of the first sub-portion 1211 is greater than the thickness t3 of the second sub-portion 1212, so that the first sub-portion 1211 and the second sub-portion 1212 form a stepped structure.

[0650] The thickness t1 of the transition portion 1222 is greater than or equal to the thickness t2 of the first sub-portion 1211. For example, the thickness t1 of the transition portion 1222 can be equal to the thickness t2 of the first sub-portion 1211, so that the transition portion 1222 and the first sub-portion 1211 form an equal thickness structure; or the thickness t1 of the transition portion 1222 can be greater than the thickness t3 of the second sub-portion 1212, so that the first sub-portion 1211 and the transition portion 1222 form a stepped structure.

[0651] In some examples, the first sub-portion 1211 can also be of multi-segment structure, along the direction of the first metal portion 121 pointing to the protruding portion 1221, the thickness of each segment increases in turn; for example, the first sub-portion 1211 includes a first segment and a second segment, the first segment is located between the second segment and the second sub-portion 1212, along the direction of the first metal portion 121 pointing to the protruding portion 1221, the thickness of the first segment gradually increases, the second segment is generally of equal thickness structure, and the thickness of the second segment is equal to the thickness t1 of the transition portion 1222; the thickness of the first segment gradually increases from the thickness t3 of the second sub-portion 1212 to the thickness of the second segment, in this way, the first segment can smoothly connect the second segment and the second sub-portion 1212, which is conducive to reducing stress concentration and improving structural strength. The thickness of the first segment can be equal to the thickness t1 of the transition portion 1222, or can be less than the thickness t1 of the transition portion 1222.

[0652] In the use of the battery cell 100, in the direction of the first metal part 121 pointing to the protruding part 1221, the electrons generated by the active material layer 20 gradually converge on the transition part 1222 through the first metal part 121, and the number of electrons flowing through the part of the first metal part 121 close to the transition part 1222 is more than the number of electrons flowing through the part of the first metal part 121 away from the transition part 1222, so it is required that the overcurrent capacity of the part of the first metal part 121 close to the transition part 1222 is greater than the overcurrent capacity of the part of the first metal part 121 away from the transition part 1222.

[0653] And the first sub-part 1211 of the embodiment of the application is connected between the second sub-part 1212 and the transition part 1222, and the thickness t2 of the first sub-part 1211 is greater than the thickness t3 of the second sub-part 1212, so that the overcurrent capacity of the first sub-part 1211 close to the transition part 1222 is greater than the overcurrent capacity of the second sub-part 1212 away from the transition part 1222, which can reduce the current limitation, improve the overcurrent capacity of the first pole piece 1, reduce the heating of the battery cell 100, and be beneficial to improve the use reliability of the battery cell 100.

[0654] In some embodiments, the current collector 10 further comprises a conductive protective layer 13, the conductive protective layer 13 comprises a first protective part 131 and a second protective part 132, the first protective part 131 is located between the first sub-part 1211 and the active material layer 20, and the second protective part 132 is located between the second sub-part 1212 and the active material layer 20; the thickness of the first protective part 131 is less than the thickness of the second protective part 132.

[0655] In some examples, in the first direction Z, the part of the conductive protective layer 13 between the first sub-part 1211 and the active material layer 20 can be the first protective part 131, and the part of the conductive protective layer 13 between the second sub-part 1212 and the active material layer 20 can be the second protective part 132, wherein the thickness t4 of the first protective part 131 is less than the thickness t5 of the second protective part 132, and the thickness t2 of the first sub-part 1211 is greater than the thickness t3 of the second sub-part 1212, which can reduce the difference between the thickness of the current collector 10 at the first protective part 131 and the thickness at the second protective part 132.

[0656] For example, the first protection part 131 is a third section and a fourth section, the third section is located between the first section and the active material layer 20, and the fourth section is located between the second section and the active material layer 20, the third section is located between the fourth section and the second protection part 132, and the thickness of the third section gradually decreases in the direction of the first metal part 121 pointing to the protruding part 1221, and the fourth section is generally an equal-thickness structure, so that the thickness t4 of the first protection part 131 can be matched with the thickness t2 of the first sub-part 1211, and the surface of the conductive protection layer 13 away from the insulating substrate 11 is close to a plane.

[0657] By adopting the technical scheme of the embodiment, the surface of the conductive protection layer 13 away from the insulating substrate 11 is close to a plane, which is beneficial to reduce the roll pressing damage and improve the overcurrent capacity of the metal layer 12, and in addition, the winding bulging problem of the current collector 10 can also be reduced.

[0658] In some embodiments, the conductive protection layer 13 further comprises a third protection part 133, the third protection part 133 covers the surface of the transition part 1222 away from the insulating substrate 11, and the thickness of the third protection part 133 is less than or equal to the thickness of the first protection part 131.

[0659] In some examples, along the first direction Z, the conductive protection layer 13 can be divided into three parts, a part close to the conductive member 30 is the third protection part 133, a part away from the conductive member 30 is the second protection part 132, and a part in the middle is the first protection part 131. The thickness t4 of the first protection part 131 is less than the thickness t5 of the second protection part 132, and the thickness t2 of the first sub-part 1211 is greater than the thickness t3 of the second sub-part 1212, which can reduce the thickness difference of the current collector 10 at the first protection part 131 and the second protection part 132; similarly, the thickness t6 of the third protection part 133 is less than or equal to the thickness t4 of the first protection part 131, and the thickness t1 of the transition part 1222 is greater than or equal to the thickness t2 of the first sub-part 1211, which can reduce the thickness difference of the current collector 10 at the first protection part 131 and the third protection part 133, and is beneficial to the surface of the conductive protection layer 13 away from the metal layer 12 close to a plane.

[0660] For example, the second protection part 132, the third protection part 133, the transition part 1222, and the second sub-part 1212 are all equal-thickness structures, and the first sub-part 1211 and the first protection part 131 are all unequal-thickness structures; the thickness t2 of the first sub-part 1211 and the thickness t4 of the first protection part 131 are matched, so that the surface of the conductive protection layer 13 away from the insulating substrate 11 is close to a plane.

[0661] The third protection part 133 is arranged to protrude from the active material layer 20 and the conductive protection layer 13, so that the active material layer 20 and the metal layer 12 are better separated. In addition, the thickness of the third protection part 133 is not too large, which is beneficial to reduce material waste and save the manufacturing cost of the battery monomer 100.

[0662] In some embodiments, the thickness t7 of the protruding part 1221 is greater than or equal to the thickness t1 of the transition part 1222.

[0663] For example, the thickness t7 of the protruding part 1221 can be equal to the thickness t1 of the transition part 1222, so that the protruding part 1221 and the transition part 1222 form an equal-thickness structure.

[0664] For example, the thickness t7 of the protruding part 1221 can also be greater than the thickness t1 of the transition part 1222, so that the protruding part 1221 and the transition part 1222 form a stepped structure.

[0665] The thickness t7 of the protruding part 1221 is relatively thick, which can improve the flow capacity of the protruding part 1221, is beneficial to improve the flow capacity of the first pole piece 1, reduce the heating of the battery monomer 100, and is beneficial to improve the fast-charging performance and use reliability of the battery monomer 100.

[0666] In some embodiments, the thickness of the second active material part 22 is t8, and 0.002≤(t1-t3) / t8≤0.08.

[0667] t1-t3 can be the difference between the thicknesses of the transition part 1222 and the second sub-part 1212, to represent the thickening degree of the transition part 1222.

[0668] The value of (t1-t3) / t8 can be 0.002, 0.08, and any value between 0.002 and 0.08; for example, the value of (t1-t3) / t8 can be but is not limited to 0.002, 0.003, 0.004, 0.008, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08.

[0669] The setting of 0.002≤(t1-t3) / t8≤0.08 makes the thickness difference between the transition part 1222 and the second sub-part 1212 within the thickness error range of the active material layer 20, so that the thickening of the transition part 1222 does not easily cause the surface of the active material layer 20 to protrude, which can reduce subsequent roll damage and subsequent extrusion damage between the first pole piece 1 and other pole pieces, and is beneficial to improve the use reliability of the battery monomer 100.

[0670] In some embodiments, 0.003≤(t1-t3) / t8≤0.06. The embodiments of the present application enable the thickness difference of the transition portion 1222 and the second sub-portion 1212 to be better within the thickness difference range of the active material layer 20, so that the thickening of the transition portion 1222 is less likely to cause the surface of the active material layer 20 to protrude, which can reduce subsequent roll damage and subsequent extrusion damage between the first pole piece 1 and other pole pieces, thereby improving the use reliability of the battery monomer 100.

[0671] In some embodiments, 60μm≤t8≤250μm.

[0672] It can be understood that the value of t8 can be 60μm, 250μm, and any value within the range of 60μm-250μm; for example, the value of t8 can be, but is not limited to, 60μm, 70μm, 80μm, 90μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, 220μm, 250μm.

[0673] The design of t8≥60μm enables the battery monomer 100 to have a higher capacity; the design of t8≤250μm enables the distance of electron extraction in the part of the active material layer 20 close to the metal layer 12 to be not too long, and the electron extraction in the part of the active material layer 20 close to the metal layer 12 is easy, which is conducive to improving the capacity of the battery monomer 100.

[0674] The thickness of the second active material portion 22 is within a suitable range, and the volume of the active material layer 20 is reasonably set, which is conducive to improving the fast-charging performance and use reliability of the battery monomer 100, and can also reduce the risk of ion extraction difficulty in the region of the active material layer 20 close to the conductive layer, thereby improving the performance of the battery monomer 100.

[0675] In some embodiments, 80μm≤t8≤180μm.

[0676] By adopting the technical solutions of the embodiments, the setting of 80μm≤t8≤180μm enables the thickness of the second active material portion 22 to be within a more suitable range, and the volume of the active material layer 20 is reasonably set, which is conducive to improving the fast-charging performance and use reliability of the battery monomer 100, and can also reduce the risk of ion extraction difficulty in the region of the active material layer 20 close to the conductive layer, thereby improving the performance of the battery monomer 100.

[0677] In some embodiments, 0.2μm≤t1-t3≤4.5μm.

[0678] It can be understood that the value of t1-t3 can be 0.2 μm, 4.5 μm, and any value between 0.2 μm and 4.5 μm; for example, the value of t1-t3 can be, but is not limited to, 0.2 μm, 0.3 μm, 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 1.75 μm, 2 μm, 3 μm, 4 μm, 4.5 μm.

[0679] By adopting the technical solution of this embodiment, the design of 0.2 μm≤t1-t3≤4.5 μm, the thickening degree of the transition portion 1222 is reasonable, on the basis of improving the flow capacity, the thickness of the transition portion 1222 is not too large to occupy a large space and weight, which is beneficial to improve the energy density of the battery monomer 100.

[0680] In some embodiments, 0.3 μm≤t1-t3≤1.75 μm.

[0681] By adopting the technical solution of this embodiment, the design of 0.3 μm≤t1-t3≤1.75 μm, the thickening degree of the transition portion 1222 is more reasonable, the flow capacity is better, and it is also more beneficial to improve the energy density of the battery monomer 100.

[0682] In some embodiments, 1

[0683] t1 / t3 can refer to the ratio of the thickness t1 of the transition portion 1222 to the thickness t3 of the second sub-portion 1212, and can also represent the thickening degree of the transition portion 1222.

[0684] It can be understood that the value of t1 / t3 can be 4 and any value between 1 and 4; for example, the value of t1 / t3 can be, but is not limited to, 1.1, 1.5, 2, 2.5, 3, 3.5, 4.

[0685] By adopting the technical solution of this embodiment, the design of 1

[0686] In some embodiments, 1.5≤t1 / t3≤2.5. By adopting the technical solution of this embodiment, the thickening degree of the transition portion 1222 is more reasonable, the flow capacity is better, and it is also more beneficial to improve the energy density of the battery monomer 100.

[0687] In some embodiments, 1 μm≤t1≤5 μm.

[0688] It can be understood that the value of t1 can be 1 pm, 5 pm, and any value between 1 pm and 5 pm; for example, the value of t1 can be, but is not limited to, 1 pm, 1.1 pm, 1.2 pm, 1.5 pm, 2 pm, 2.5 pm, 3 pm, 3.5 pm, 4 pm, 5 pm.

[0689] By adopting the technical solutions of this embodiment, the design of 1 pm≤t1≤5 pm, the thickness of the transition part 1222 is reasonable, which is conducive to improving the flow capacity. In addition, the thickness of the transition part 1222 is not too large to occupy a large space and weight, which is conducive to improving the energy density of the battery monomer 100.

[0690] In some embodiments, 1.2 pm≤t1≤3.5 pm.

[0691] By adopting the technical solutions of this embodiment, the design of 1.2 pm≤t1≤3.5 pm, the thickness of the transition part 1222 is more reasonable, the flow capacity is better, and it is also more conducive to improving the energy density of the battery monomer 100.

[0692] In some embodiments, 0.03≤t6 / t5≤0.95.

[0693] t6 / t5 can refer to the ratio of the thickness of the third protective part 133 to the thickness of the second protective part 132, which can represent the thinning degree of the third protective part 133 relative to the second protective part 132.

[0694] It can be understood that the value of t6 / t5 can be 0.03, 0.95, and any value between 0.03 and 0.95; for example, the value of t6 / t5 can be, but is not limited to, 0.03, 0.1, 0.125, 0.15, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95.

[0695] By adopting the technical solutions of this embodiment, the design of 0.03≤t6 / t5≤0.95, the thinning degree of the conductive protective layer 13 is reasonable, which can better adapt to the thickening degree of the transition part 1222, which is conducive to the surface of the conductive protective layer 13 facing away from the metal layer 12 approaching a plane, which is conducive to reducing the roll damage and improving the flow capacity of the metal layer 12.

[0696] In some embodiments, 0.125≤t6 / t5≤0.8.

[0697] By adopting the technical scheme of the embodiment, the design of 0.125≤t6 / t5≤0.8 makes the thinning degree of the conductive protective layer 13 more reasonable, can better adapt to the thickening degree of the transition part 1222, is beneficial to the surface of the conductive protective layer 13 being close to a plane in the direction away from the metal layer 12, is beneficial to reducing the damage caused by rolling, and improves the current carrying capacity of the metal layer 12.

[0698] In some embodiments, 0.5 μm≤t6≤4 μm.

[0699] It can be understood that the value of t6 can be 0.5 μm, 4 μm, and any value between 0.5 μm and 4 μm; for example, the value of t6 can be, but is not limited to, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm.

[0700] By adopting the technical scheme of the embodiment, the setting of 0.5 μm≤t6≤4 μm makes the third protective part 133 have a certain thickness, thereby reducing the risk of cracking of the metal layer 12; in addition, the third protective part 133 will not protrude from the second protective part 132 due to the third protective part 133 being too thick, and material accumulation and manufacturing cost can also be reduced.

[0701] In some embodiments, 1 μm≤t6≤2 μm.

[0702] By adopting the technical scheme of the embodiment, the setting of 1 μm≤t6≤2 μm makes the third protective part 133 have a more reasonable thickness, thereby better reducing the risk of cracking of the metal layer 12 and manufacturing cost.

[0703] In some embodiments, along the first direction Z, the size of the first sub-part 1211 is W1, and the size of the second sub-part 1212 is W2, where W1 / (W1+W2)≤0.45.

[0704] For example, the size W1 of the first sub-part 1211 can refer to the width of the first sub-part 1211, and the size W2 of the second sub-part 1212 can refer to the width of the second sub-part 1212. W1+W2 can refer to the width of the first metal part 121.

[0705] W1 / (W1+W2) can refer to the proportion of the first sub-part 1211 occupying the first metal part 121 in the width direction of the first pole piece 1.

[0706] It can be understood that the value of W1 / (W1+W2) can be 0.45 and any value between 0 and 0.45; for example, the value of W1 / (W1+W2) can be, but is not limited to, 0.001, 0.1, 0.2, 0.3, 0.4, 0.45.

[0707] By adopting the technical solutions of this embodiment, the design of W1 / (W1+W2)≤0.45 makes the active material layer 20 cover the first sub-part 1211, so as to improve the flow capacity and reduce the heat generation of the battery monomer 100; in addition, along the first direction Z, the first sub-part 1211 does not occupy a large area, which is beneficial to reduce the occupied space and weight of the first sub-part 1211 and improve the energy density of the battery monomer 100.

[0708] In some embodiments, along the first direction Z, the size of the first sub-part 1211 is W2, where 10mm≤W2≤100mm.

[0709] It can be understood that the value of W2 can be 10mm, 100mm and any value between 10mm and 100mm; for example, the value of W2 can be but is not limited to 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm.

[0710] By adopting the technical solutions of this embodiment, the design of 10mm≤W2≤100mm makes the active material layer 20 cover the first sub-part 1211, so as to improve the flow capacity and reduce the heat generation of the battery monomer 100; in addition, along the first direction Z, the first sub-part 1211 does not occupy a large area, which is beneficial to reduce the occupied space and weight of the first sub-part 1211 and improve the energy density of the battery monomer 100.

[0711] FIG. 37 is a schematic view of a first insulating part of a battery monomer according to some embodiments of the present application.

[0712] Referring to FIG. 37, in some embodiments, the first insulating part 4 includes an insulating base layer 4a and an adhesive layer 4b, at least part of the adhesive layer 4b is bonded between the insulating base layer 4a and the first connecting part 31.

[0713] For example, the insulating base layer 4a can refer to the main part of the first insulating part 4 that plays an insulating role, and the adhesive layer 4b can refer to an adhesive covering the surface of the insulating base layer 4a. For example, the first insulating part 4 adopts the structure of a tape.

[0714] For example, the material of the insulating base layer 4a can include at least one of polyethylene terephthalate (PET), polypropylene, polyethylene and block copolymers thereof. The material of the adhesive layer 4b can include at least one of polyacrylate, styrene butadiene rubber, polyisobutylene or butyl rubber.

[0715] The insulating base layer 4a can have a higher structural strength, which can block the burrs and is not easy to be pierced by the burrs, thereby improving the insulation effect. Compared with the bonding layer 4b, the insulating base layer 4a has a high strength, and the deformation of the insulating base layer 4a is small during the bonding process of the first insulating part 4; the bonding layer 4b can stably fix the insulating base layer 4a on the first pole piece 1, thereby reducing the risk of falling off of the first insulating part.

[0716] In some embodiments, the first insulating part 4 is a tape. The tape is easy to cover comprehensively, thereby reducing the risk of incomplete coverage and reducing the risk of internal short circuit of the battery cell 100.

[0717] In some embodiments, the layer thickness of the insulating base layer 4a ranges from 6 μm to 15 μm.

[0718] The layer thickness of the insulating base layer 4a is T1, and 6 μm≤T1≤15 μm. The value of T1 can be 6 μm, 15 μm, and any value between 6 μm and 15 μm. For example, the value of T1 can be, but is not limited to, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm.

[0719] The design of T1≥6 μm makes the insulating base layer 4a have a certain thickness, so that the insulating base layer 4a can block the burrs and achieve insulation. The design of T1≤15 μm makes the thickness of the insulating base layer 4a not too large, thereby reducing the volume occupied by the first insulating part 4 and improving the energy density of the battery cell 100.

[0720] By adopting the technical scheme of the embodiment, the internal insulation and the energy density of the battery cell 100 can be considered to some extent.

[0721] In some embodiments, the layer thickness of the bonding layer 4b ranges from 0.5 μm to 3 μm.

[0722] The layer thickness of the bonding layer 4b is T2, and 0.5 μm≤T2≤3 μm. It can be understood that the value of T2 can be 0.3 μm, 3 μm, and any value between 0.3 μm and 3 μm. For example, the value of T2 can be, but is not limited to, 0.3 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm.

[0723] The design of T2≥0.5 μm makes the bonding layer 4b have a certain thickness, so that the first insulating part 4 can be stably bonded to the first pole piece 1, thereby improving the insulation reliability of the first insulating part 4. The design of T2≤3 μm makes the thickness of the bonding layer 4b not too large, thereby reducing the volume occupied by the first insulating part 4 and improving the energy density of the battery cell 100.

[0724] By adopting the technical solutions of the embodiment, the insulation reliability and energy density of the battery monomer 100 can be simultaneously considered.

[0725] In some embodiments, the layer thickness of the insulating base layer 4a ranges from 6 μm to 15 μm; and the layer thickness of the adhesive layer 4b ranges from 0.5 μm to 3 μm.

[0726] By adopting the technical solutions of the embodiment, the insulation reliability and energy density of the battery monomer 100 can be simultaneously considered.

[0727] FIG. 38 is a partial cross-sectional view of an electrode assembly of a battery monomer according to some embodiments of the present application.

[0728] Referring to FIG. 38, in some embodiments, the portion of the first insulating member 4 covering the active material layer 20 is configured to allow ions to pass through.

[0729] The present application can reduce the blocking of ions by the first insulating member 4 and reduce the capacity loss of the first electrode tab 1.

[0730] In some embodiments, the portion of the first insulating member 4 covering the active material layer 20 is provided with a through hole 4c. The through hole 4c can serve as a channel for ions to pass through.

[0731] The through hole 4c can be one or multiple.

[0732] In some embodiments, the insulating base layer 4a covers the active material layer 20. There is no adhesive layer 4b between the insulating base layer 4a and the active material layer 20.

[0733] In some embodiments, the insulating base layer 4a has a microporous structure. For example, the porosity of the insulating base layer 4a ranges from 20% to 80%.

[0734] Referring to FIGS. 2 to 17, the present application provides a battery monomer 100, which includes an end cover 201, a shell 202, and an electrode assembly 101. The electrode assembly 101 is installed at the shell 202, and the end cover 201 is attached to the opening of the shell 202 to seal the shell 202. The end cover 201 is provided with an electrode lead-out portion 2011.

[0735] The electrode assembly 101 includes a first electrode tab 1, a second electrode tab 2, and a separator 3. The separator 3 is located between the first electrode tab 1 and the second electrode tab 2, and the first electrode tab 1 and the second electrode tab 2 have opposite polarities. The first electrode tab 1 can be a positive electrode tab, and the second electrode tab 2 can be a negative electrode tab.

[0736] The first electrode sheet 1 includes a current collector 10, two active material layers 20, and two conductive members 30. The current collector 10 includes an insulating base 11 and two metal layers 12 arranged on opposite sides of the insulating base 11 in the thickness direction Y of the current collector. The two active material layers 20 are respectively arranged on the two metal layers 12.

[0737] The metal layer 12 includes a first metal portion 121 and a second metal portion 122 arranged in a first direction Z and connected to each other. The first metal portion 121 is covered with the active material layer 20, and the second metal portion 122 is not covered with the active material layer 20. The second metal portion 122 includes a transition portion 1222 and a plurality of protruding portions 1221. The transition portion 1222 is connected between the first metal portion 121 and the plurality of protruding portions 1221. The plurality of protruding portions 1221 are arranged at intervals in a second direction X. The second direction X, the first direction Z, and the thickness direction Y of the current collector are perpendicular to each other. For example, the second direction X can be the winding direction of the first electrode sheet 1.

[0738] The conductive member 30 includes a first connecting portion 31 and a plurality of second connecting portions 32. The first connecting portion 31 includes a plurality of first connecting sub-portions 311 and a second connecting sub-portion 312. The second connecting sub-portion 312 is located on the side of the transition portion 1222 away from the insulating base 11 and is welded to the transition portion 1222. The plurality of first connecting sub-portions 311 are arranged one-to-one corresponding to the plurality of protruding portions 1221. The first connecting sub-portion 311 is covered on the corresponding protruding portion 1221 and is welded to the protruding portion 1221. The second connecting sub-portion 312 continuously extends in the second direction X and is connected to the plurality of first connecting sub-portions 311.

[0739] The plurality of second connecting portions 32 correspond one-to-one to the plurality of first connecting sub-portions 311. The second connecting portion 32 extends from the corresponding first connecting sub-portion 311 away from the end of the second connecting sub-portion 312. In the direction of the active material layer 20 pointing to the first connecting portion 31, the second connecting portion 32 protrudes from the protruding portion 1221 as a whole.

[0740] The second connecting portions 32 of the plurality of conductive members 30 are connected to the electrode lead-out portion 2011.

[0741] The electrode assembly 101 further includes two first insulating members 4 located on both sides of the first electrode sheet 1. The two first insulating members 4 are respectively attached to the two conductive members 30.

[0742] In the direction of the active material layer 20 pointing to the first connecting portion 31, the first insulating member 4 protrudes from the end face of the second connecting sub-portion 312 away from the active material layer 20. In the direction of the first connecting portion 31 pointing to the active material layer 20, the first insulating member 4 protrudes from the end face of the second connecting sub-portion 312 facing the active material layer 20.

[0743] Optionally, the first insulating member 4 completely covers the plurality of first connecting sub portions 311 and the plurality of second connecting sub portions 312. Optionally, the first insulating member 4 completely covers the transition portion 1222.

[0744] According to some embodiments of the present application, the present application also provides a battery device 1100 comprising a plurality of the battery cell 100 of any one of the above embodiments.

[0745] The present application also provides a power consuming device comprising the battery device 1100 of any one of the above embodiments, the battery device 1100 being configured to provide electric energy for the power consuming device. The power consuming device can be any one of the devices or systems as described above.

[0746] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, comprising: a housing provided with an electrode lead-out portion; an electrode assembly at least partially housed in the housing, the electrode assembly including a first electrode tab and a first insulating member; the first electrode tab including a conductive member, a current collector, and an active material layer, the current collector including an insulating base and a metal layer, the insulating base, the metal layer, and the active material layer being stacked in a thickness direction of the current collector, at least a portion of the metal layer being located between the insulating base and the active material layer, the conductive member being configured to electrically connect the metal layer and the electrode lead-out portion; the conductive member including a first connecting portion, the first connecting portion being located on a side of the metal layer facing away from the insulating base and connected to the metal layer, the active material layer being disposed in a first direction with respect to the first connecting portion, the first direction being perpendicular to the thickness direction of the current collector; at least a portion of the first insulating member being located on a side of the first connecting portion facing away from the metal layer and attached to the first connecting portion, the first insulating member protruding from a first end surface of the first connecting portion facing the active material layer in a direction of the first connecting portion pointing toward the active material layer.

2. The battery cell of claim 1, wherein, the first connecting portion and the active material layer are spaced apart in the first direction.

3. The battery cell of claim 2, wherein, the first insulating member at least partially covers a region of the metal layer between the first connecting portion and the active material layer.

4. The battery cell of claim 2 or 3, wherein, a portion of the first insulating member is located between the first connecting portion and the active material layer in the first direction; the portion of the first insulating member between the first connecting portion and the active material layer is attached to the metal layer.

5. The battery cell of claim 2 or 3, wherein, the electrode assembly includes a second insulating member disposed on a surface of the metal layer facing away from the insulating base; at least a portion of the second insulating member is located between the first connecting portion and the active material layer in the first direction.

6. The battery cell of claim 5, wherein, a portion of the first insulating member is located on a side of the second insulating member facing away from the metal layer and connected to the second insulating member.

7. The battery cell of any one of claims 1-6, wherein, the first insulating member is further connected to the active material layer.

8. The battery cell of any one of claims 1-7, wherein, the first insulating member covers a portion of the active material layer.

9. The battery cell of claim 8, wherein, the portion of the first insulating member covering the active material layer is configured to allow ions to pass through.

10. The battery cell of claim 8 or 9, wherein, the portion of the first insulating member covering the active material layer is provided with a through hole.

11. The battery cell of claim 8, wherein, the first insulating member is configured to block ions from passing through.

12. The battery cell of any one of claims 8-11, wherein, the active material layer includes a first active material portion and a second active material portion arranged in the first direction, the first active material portion being located on a side of the second active material portion facing the first connecting portion, a thickness of the first active material portion at an end of the first active material portion facing away from the second active material portion being less than a thickness of the second active material portion, the thickness of the first active material portion decreasing in a direction of the first connecting portion with respect to the active material layer; the first insulating member covers at least a portion of the first active material portion.

13. The battery cell of any one of claims 8-12, wherein, In the first direction, the first insulating member covers a portion of the active material layer with a size of 0.2 mm to 1 mm.

14. The battery cell of any one of claims 1-13, wherein, The metal layer includes a first metal portion and a second metal portion arranged along the first direction and connected to each other, the first metal portion being covered with the active material layer, and the second metal portion not being covered with the active material layer. The first connecting portion is welded to the second metal portion and forms a first welding mark.

15. The battery cell of claim 14, wherein, The second metal portion includes at least one protruding portion, and in a second direction, a sum of sizes of all the protruding portions is less than a size of the first metal portion, the second direction being perpendicular to the first direction and a thickness direction of the current collector. The first connecting portion includes at least one first connecting sub-portion, the first connecting sub-portion being located on a side of the protruding portion away from the insulating base, and the first connecting sub-portion corresponding to the protruding portion one by one.

16. The battery cell of claim 15, wherein, The first insulating member includes at least one first insulating sub-portion, the first insulating sub-portion covering a surface of the first connecting sub-portion away from the protruding portion, and the first insulating sub-portion corresponding to the first connecting sub-portion one by one.

17. The battery cell of claim 16, wherein, The first insulating member further includes a second insulating sub-portion connected to the first insulating sub-portion, the second insulating sub-portion being located on a side of the first insulating sub-portion facing the active material layer in the first direction.

18. The battery cell of claim 16 or 17, wherein, The first insulating member further includes a third insulating sub-portion connected to the first insulating sub-portion, the third insulating sub-portion being arranged along the second direction with the first insulating sub-portion.

19. The battery cell of claim 18, wherein, The current collector includes two metal layers, the two metal layers being arranged on opposite sides of the insulating base along a thickness direction of the current collector. The first electrode tab includes two active material layers and two conductive members, the two active material layers being arranged on the two metal layers respectively, and the first connecting portions of the two conductive members being connected to the second metal portions of the two metal layers respectively. The electrode assembly includes two first insulating members, the two first insulating members being attached to the two first connecting portions respectively.

20. The battery cell of claim 19, wherein, The third insulating sub-portions of the two first insulating members are attached and / or connected.

21. The battery cell of any one of claims 16-20, wherein, The first insulating member further includes a fourth insulating sub-portion connected to the first insulating sub-portion, the fourth insulating sub-portion being located on a side of the first insulating sub-portion away from the active material layer in the first direction.

22. The battery cell of any one of claims 16-21, wherein, The first connecting sub-portion is welded to the protruding portion and forms a first welding mark portion, the first welding mark including the first welding mark portion; and the first insulating sub-portion covers at least a portion of the first welding mark portion.

23. The battery cell of claim 22, wherein, In the first direction, both ends of the first welding mark portion do not exceed the first insulating sub-portion.

24. The battery cell of any one of claims 15-23, wherein, The number of the protruding portions is plural, and the plural protruding portions are arranged along the second direction at intervals. The first connecting portion includes plural first connecting sub-portions, the plural first connecting sub-portions being arranged along the second direction at intervals, and the plural first connecting sub-portions corresponding to the plural protruding portions one by one.

25. The battery cell of claim 24, wherein, The first insulating member includes a plurality of first insulating sub-members arranged along the second direction, the first insulating sub-members being arranged on the surface of the first connecting sub-member facing away from the protruding member.

26. The battery cell of claim 25, wherein, The first insulating member further includes a second insulating sub-member, the second insulating sub-member being arranged on the side of the plurality of first insulating sub-members facing the active material layer along the first direction. The second insulating sub-member continuously extends along the second direction and is connected to the plurality of first insulating sub-members.

27. The battery cell of claim 25, wherein, The first insulating member further includes a plurality of second insulating sub-members, the plurality of first insulating sub-members and the plurality of second insulating sub-members being arranged one-to-one, and the first insulating sub-member being connected to the corresponding second insulating sub-member. The second insulating sub-member is arranged on the side of the first insulating sub-member facing the active material layer along the first direction.

28. The battery cell of any one of claims 25-27, wherein, The first insulating member includes a plurality of third insulating sub-members arranged along the second direction, and each of the first insulating members is connected to two third insulating sub-members at both ends thereof along the second direction.

29. The battery cell of claim 28, wherein, The plurality of first insulating sub-members and the plurality of third insulating sub-members are alternately arranged along the second direction, and two first insulating sub-members are connected by one third insulating sub-member.

30. The battery cell of claim 28, wherein, Along the second direction, two third insulating sub-members are arranged between two adjacent first insulating sub-members.

31. The battery cell of any one of claims 25-30, wherein, The first insulating member further includes a plurality of fourth insulating sub-members, the plurality of first insulating sub-members and the plurality of fourth insulating sub-members being arranged one-to-one, and the first insulating sub-member being connected to the corresponding fourth insulating sub-member. The fourth insulating sub-member is arranged on the side of the first insulating sub-member facing away from the active material layer along the first direction.

32. The battery cell of any one of claims 24-31, wherein, Each of the first connecting sub-members has a second end surface at the end thereof facing the active material layer, and the second end surfaces of the plurality of first connecting sub-members form the first end surface.

33. The battery cell of any one of claims 15-31, wherein, The second metal member further includes a transition member connected between the first metal member and the protruding member. Along the second direction, the size of the transition member is greater than the sum of the sizes of all the protruding members.

34. The battery cell of claim 33, wherein, The first connecting member includes a second connecting sub-member arranged on the side of the transition member facing away from the insulating base along the thickness direction of the current collector, and the first connecting sub-member is connected to the end surface of the second connecting sub-member away from the active material layer. Along the first direction, the end surface of the second connecting sub-member facing the active material layer is the first end surface.

35. The battery cell of claim 34, wherein, The first insulating member includes a second insulating sub-member arranged on the second connecting sub-member, and the second insulating sub-member protrudes from the first end surface along the direction of the second metal member pointing to the first metal member.

36. The battery cell of claim 35, wherein, Along the second direction, the second insulating sub-member protrudes from the second connecting sub-member.

37. The battery cell of claim 35 or 36, wherein, The first insulating member further comprises a first insulating sub-member and a third insulating sub-member, the first insulating sub-member and the third insulating sub-member are connected to the second insulating sub-member; in the first direction, the first insulating sub-member and the third insulating sub-member are located on the side of the second insulating sub-member away from the active material layer; The first insulating sub-member covers the surface of the first connecting sub-member away from the protruding part; The first insulating sub-member and the third insulating sub-member are arranged along the second direction and are connected.

38. The battery cell of any one of claims 35-37, wherein, The second connecting sub-member is welded to the surface of the transition part away from the insulating base and forms a second welding mark part, and the first welding mark includes the second welding mark part; The second insulating sub-member covers at least part of the second welding mark part.

39. The battery cell of claim 38, wherein, In the first direction, both ends of the second welding mark part do not exceed the second insulating sub-member.

40. The battery cell of claim 38 or 39, wherein, In the second direction, the size of the transition part is L2, the size of the second welding mark part is L3, and 0.8≤L3 / L2≤1.

41. The battery cell of any one of claims 34-40, wherein, The end surface of the second connecting sub-member away from the active material layer is flush with the end surface of the transition part away from the first metal part.

42. The battery cell of any one of claims 34-41, wherein, The number of protruding parts is multiple, and multiple protruding parts are arranged at intervals along the second direction; The first connecting part includes the second connecting sub-member and multiple first connecting sub-members, multiple first connecting sub-members are arranged at intervals along the second direction, and each first connecting sub-member is welded to each protruding part and forms a first welding mark part; The second connecting sub-member is arranged continuously along the second direction, welded to the transition part, and forms a second welding mark part; The first welding mark includes the second welding mark part and multiple first welding mark parts.

43. The battery cell of any one of claims 15-42, wherein, The protruding part includes a first protruding sub-member and a second protruding sub-member, the first protruding sub-member is connected between the second protruding sub-member and the first metal part; In the second direction, the size of the first protruding sub-member is greater than the size of the second protruding sub-member; The first connecting sub-member includes a first connecting convex part and a second connecting convex part, the first connecting convex part is located on the side of the first protruding sub-member away from the insulating base, and the second connecting convex part is located on the side of the second protruding sub-member away from the insulating base; in the second direction, the size of the first connecting convex part is greater than the size of the second connecting convex part; The first insulating member includes at least one first insulating sub-member, and the first insulating sub-member corresponds to the first connecting sub-member one by one; The first insulating sub-member covers the first connecting convex part and the second connecting convex part.

44. The battery cell of claim 14, wherein, The second metal part includes a transition part, in the second direction, both ends of the transition part are flush with both ends of the first metal part, and the second direction is perpendicular to the first direction and the thickness direction of the current collector; The first connecting part includes a second connecting sub-member, the second connecting sub-member is located on the side of the transition part away from the insulating base, the second connecting sub-member is welded to the surface of the transition part away from the insulating base and forms a second welding mark part, and the first welding mark includes the second welding mark part; The end surface of the second connecting sub facing the active material layer is the first end surface.

45. The battery cell of claim 44, wherein, The first insulating member protrudes from the end surface of the second connecting sub facing away from the active material layer in a direction pointing from the first metal part to the second metal part.

46. The battery cell of claim 44 or 45, wherein, In the second direction, both ends of the first insulating member protrude from the second connecting sub.

47. The battery cell of any one of claims 34-41, 44-46, wherein, The electrode assembly further comprises a second tab opposite in polarity to the first tab, the second tab comprising a main functional part and a tab part, the tab part extending from an end surface of the main functional part in the first direction; In a direction pointing from the active material layer to the first connecting part, the end surface of the second connecting sub facing away from the active material layer exceeds the main functional part.

48. The battery cell of any one of claims 1-47, wherein, The electrode assembly further comprises a second tab opposite in polarity to the first tab, the second tab comprising a main functional part and a tab part, the tab part extending from an end surface of the main functional part in the first direction; In a direction pointing from the active material layer to the first connecting part, the end surface of the main functional part facing towards the tab part exceeds the first end surface; The first insulating member separates the first end surface from the main functional part.

49. The battery cell of claim 48, wherein, In a direction pointing from the active material layer to the first connecting part, the end surface of the first insulating member facing towards the tab part exceeds the main functional part.

50. The battery cell of any one of claims 1-49, wherein, The current collector comprises two metal layers, the two metal layers being arranged on opposite sides of the insulating substrate along the thickness direction of the current collector; The first tab comprises two active material layers and two conductive members, the two active material layers being arranged on the two metal layers respectively, and the first connecting parts of the two conductive members being connected to the two metal layers respectively; The electrode assembly comprises two first insulating members, the two first insulating members being attached to the first connecting parts of the two conductive members respectively.

51. The battery cell of claim 50, wherein, A portion of the two first insulating members is attached and / or connected.

52. The battery cell of claim 50 or 51, wherein, The conductive member further comprises a second connecting part connected to the first connecting part, the second connecting part being located on a side of the first connecting part facing away from the active material layer in the first direction; the second connecting part is electrically connected to the electrode lead-out part; The second connecting parts of the two conductive members are welded and form a second welding mark.

53. The battery cell of claim 52, wherein, The first insulating member covers at least a portion of the second welding mark.

54. The battery cell of claim 53, wherein, In a direction pointing from the active material layer to the first connecting part, the first insulating member protrudes from the edge of the second welding mark away from the active material layer.

55. The battery cell of any one of claims 1-54, wherein, The metal layer comprises a first metal part and a second metal part arranged and connected in the first direction, the first metal part being covered with the active material layer, and the second metal part not being covered with the active material layer; The second metal part comprises a transition part and at least one protruding part; the transition part is connected between the first metal part and the protruding part; The second metal part comprises a transition part and at least one protruding part; the transition part is connected between the first metal part and the protruding part; In a second direction perpendicular to the first direction and a thickness direction of the current collector, a size of the transition portion is greater than a sum of sizes of all the protruding portions; The first connecting portion is welded to the second metal portion and forms a first welding mark.

56. The battery cell of claim 55, wherein, In the second direction, a size of the first metal portion is L1, and a size of the transition portion is L2, and 0.8≤L2 / L1≤1.

57. The battery cell of claim 55 or 56, wherein, At least a partial thickness of the first metal portion is less than a thickness of the transition portion.

58. The battery cell of claim 57, wherein, The first metal portion includes a first sub-portion and a second sub-portion, the first sub-portion is connected between the second sub-portion and the transition portion, the first sub-portion and the second sub-portion are covered by the active material layer, a thickness of the first sub-portion is greater than a thickness of the second sub-portion, and a thickness of the transition portion is greater than or equal to the thickness of the first sub-portion.

59. The battery cell of claim 58, wherein, The current collector further includes a conductive protective layer, the conductive protective layer includes a first protective portion and a second protective portion, the first protective portion is located between the first sub-portion and the active material layer, and the second protective portion is located between the second sub-portion and the active material layer; a thickness of the first protective portion is less than a thickness of the second protective portion.

60. The battery cell of claim 59, wherein, The conductive protective layer further includes a third protective portion, the third protective portion covers a surface of the transition portion away from the insulating base body, and a thickness of the third protective portion is less than or equal to the thickness of the first protective portion.

61. The battery cell of any one of claims 55-60, wherein, A thickness of the protruding portion is greater than or equal to a thickness of the transition portion.

62. The battery cell of any one of claims 1-61, wherein, The conductive member further includes at least one second connecting portion connected to the first connecting portion, in the first direction, the second connecting portion is located on a side of the first connecting portion away from the active material layer; and the second connecting portion is electrically connected to the electrode lead-out portion.

63. The battery cell of claim 62, wherein, The first connecting portion includes a plurality of first connecting sub-portions, the plurality of first connecting sub-portions are arranged at intervals in a second direction perpendicular to the first direction and a thickness direction of the current collector; Each of the first connecting sub-portions is connected to the metal layer; The number of the second connecting portions is plural, and each of the first connecting sub-portions is connected to each of the second connecting portions one by one.

64. The battery cell of any one of claims 1-63, wherein, The first connecting portion is welded to a surface of the metal layer away from the insulating base body and forms a first welding mark; In the first direction, a spacing between the first welding mark and the active material layer is S1, and 0.3mm≤S1≤5mm, and optionally, 0.5mm≤S1≤2.8mm.

65. The battery cell of any one of Claims 1-64, wherein, The current collector further includes a conductive protective layer, at least a portion of the conductive protective layer is located between the active material layer and the metal layer.

66. The battery cell of claim 65, wherein, In a direction of the active material layer pointing to the first connecting portion, an end surface of the conductive protective layer protruding from the active material layer towards the first connecting portion.

67. The battery cell of claim 66, wherein, In the direction of the active material layer pointing to the first connecting portion, a protruding length of the end surface of the conductive protective layer protruding from the active material layer towards the first connecting portion ranges from 0.3mm to 0.8mm.

68. The battery cell of any one of claims 65-67, wherein, In the first direction, the conductive protective layer and the first connecting portion are arranged at intervals.

69. The battery cell of any one of claims 1-68, wherein, The first insulating component includes an insulating base layer and a bonding layer, at least part of the bonding layer is bonded between the insulating base layer and the first connecting portion.

70. The battery cell of claim 69, wherein, The insulating base layer has a layer thickness in a range of 6 μm to 15 μm; and / or the bonding layer has a layer thickness in a range of 0.5 μm to 3 μm.

71. The battery cell of any one of claims 1-70, wherein, In the first direction, the first insulating component has a dimension W, 3 mm ≤ W ≤ 9 mm, optionally 4.5 mm ≤ W ≤ 6.5 mm.

72. A battery device comprising the battery cell of any one of claims 1-71.

73. An electrically powered device comprising the battery device of claim 72, the battery device being configured to provide electrical power.

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