CN-122029688-A - Battery cell, battery device and electricity utilization device

CN122029688ACN 122029688 ACN122029688 ACN 122029688ACN-122029688-A

Abstract

A battery cell (100), a battery device (1100) and an electric device, wherein the battery cell (100) comprises a shell (200) and an electrode assembly (101), the shell (200) is provided with an electrode leading-out part (2011), the electrode assembly (101) is at least partially accommodated in the shell (200), the electrode assembly (101) comprises a first pole piece (1), the first pole piece (1) comprises a conductive component (30), a current collector (10) and an active substance layer (20), the conductive component (30) is connected with the electrode leading-out part (2011), the current collector (10) comprises an insulating base (11) and a metal layer (12), the insulating base (11), the metal layer (12) and the active substance layer (20) are stacked along the thickness direction of the current collector (10), at least part of the metal layer (12) is positioned between the insulating base (11) and the active substance layer (20), the metal layer (12) comprises a conductive part (121) and an extension part (122) which extends outwards from the end part of the conductive part (121) along the first direction, the first direction is perpendicular to the thickness direction of the current collector (10), the conductive part (121) is covered with the active substance layer (20), the extension part (122) is not covered with the active material layer (20), the conductive member (30) is welded on the surface of the extension part (122) facing away from the insulating substrate (11) and forms a first welding mark (51), and the distance between the first welding mark (51) and the active material layer (20) ranges from 0.3mm to 5mm.

Inventors

WU ZHIYANG
ZHANG YU
XUE QINGRUI
ZHANG JINSONG
ZHAO ZHENGYUAN

Assignees

宁德时代新能源科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20240723

Claims (20)

A battery cell, comprising: a housing provided with an electrode lead-out portion; The electrode assembly is at least partially accommodated in the shell, and comprises a first pole piece, a second pole piece and a third pole piece, wherein the first pole piece comprises a conductive member, a current collector and an active material layer, the conductive member is connected with the electrode lead-out part, the current collector comprises an insulating matrix and a metal layer, the insulating matrix, the metal layer and the active material layer are stacked along the thickness direction of the current collector, and at least part of the metal layer is positioned between the insulating matrix and the active material layer; The metal layer comprises a conductive part and an extension part which extends outwards from the end part of the conductive part along a first direction, wherein the first direction is perpendicular to the thickness direction of the current collector; The conductive member is welded on the surface of the extension part, which is opposite to the insulating substrate, and forms a first welding mark, and the distance between the first welding mark and the active material layer is 0.3 mm-5 mm.
The battery cell of claim 1, wherein the first solder and the active material layer have a spacing in the range of 0.5mm to 2.8mm.
The battery cell according to claim 1 or 2, wherein the conductive member includes a first connection part and at least one second connection part, the first connection part and the second connection part being aligned in the first direction, the first connection part and the second connection part being connected, the second connection part being connected to the electrode lead-out part, the first connection part being welded to a surface of the extension part facing away from the insulating base body and forming the first weld, the second connection part being located at a side of the extension part facing away from the conductive part.
The battery cell according to claim 3, wherein the first solder is spaced from the first connecting portion toward the end face of the active material layer in the first direction.
The battery cell according to claim 4, wherein a distance between the first solder and an end surface of the first connecting portion facing the active material layer in the first direction is in a range of 0.3mm to 1.2mm.
The battery cell according to any one of claims 3 to 5, wherein the first solder comprises a first solder portion, the extension portion comprises at least one protruding portion, the protruding portion is connected with the conductive portion, and the first connection portion is soldered to a surface of the protruding portion facing away from the insulating substrate and forms the first solder portion; The size of the protruding portion is smaller than the size of the conductive portion in a second direction perpendicular to the first direction and the thickness direction of the current collector.
The battery cell of claim 6, wherein the first weld extends from one side of the protrusion to the other side of the protrusion in the second direction.
The battery cell of claim 6 or 7, wherein the tab comprises a first tab portion and a second tab portion, the second tab portion being connected between the conductive portion and the first tab portion; Along the second direction, the second protrusion has a size smaller than the first protrusion, and the first protrusion has a size smaller than the conductive portion; The first welding part comprises a first welding sub-part, and the first connecting part is welded on the surface of the first protruding sub-part, which is opposite to the insulating substrate, and forms the first welding sub-part.
The battery cell of claim 8, wherein the first solder pad sub-portion extends from one side of the first tab sub-portion to the other side of the first tab sub-portion in the second direction.
The battery cell according to claim 8 or 9, wherein the first solder portion further includes a second solder sub-portion, and the first connection portion is soldered to a surface of the second projection sub-portion facing away from the insulating substrate and forms the second solder sub-portion.
The battery cell of claim 10, wherein the second solder pad portion extends from one side of the second tab portion to the other side of the second tab portion in the second direction.
The battery cell according to any one of claims 6 to 11, wherein the number of the protruding portions is plural, the protruding portions are arranged at intervals along a second direction, each protruding portion is welded with the first connecting portion, and the second direction is perpendicular to the first direction and the thickness direction of the current collector.
The battery cell of claim 12, wherein the first connection part comprises a plurality of first connection sub-parts, the plurality of first connection sub-parts are arranged at intervals along the second direction, the number of the second connection parts is a plurality, and each first connection sub-part is connected with each second connection part in a one-to-one correspondence; Each first connecting sub-part is welded on the surface of each protruding part, which faces away from the insulating substrate, in a one-to-one correspondence manner.
The battery cell according to any one of claims 6 to 13, wherein the first solder comprises a second solder portion, the extension portion further comprises a transition portion, the transition portion is connected between the protruding portion and the conductive portion, and the first connection portion is welded to a surface of the transition portion facing away from the insulating substrate and forms the second solder portion; In the second direction, the size of the transition portion is larger than the sum of the sizes of all the protruding portions.
The battery cell of claim 14, wherein the conductive portion has a dimension L 1 and the transition portion has a dimension L 2 ,0.8≤L 2 /L 1 ≤1 in the second direction.
The battery cell of claim 14 or 15, wherein the transition portion has a dimension L 2 and the second weld portion has a dimension L 3 ,0.8≤L 3 /L 2 ≤1 in the second direction.
The battery cell according to any one of claims 14 to 16, wherein the number of the protruding parts is plural, and the protruding parts are arranged at intervals along the second direction; The first connecting parts comprise second connecting sub-parts and a plurality of first connecting sub-parts, the first connecting sub-parts are arranged at intervals along the second direction, and the first connecting sub-parts are welded on the surface of the protruding parts, which is opposite to the insulating substrate, in a one-to-one correspondence manner; The number of the second connecting parts is multiple, one side of each first connecting sub-part is connected with each second connecting part in a one-to-one correspondence manner along the first direction, the other side of each first connecting sub-part is connected with the second connecting sub-part, and the second connecting sub-parts are continuously arranged along the second direction; The second connector part is welded on the surface of the transition part, which is opposite to the insulating substrate.
The battery cell according to any one of claims 3 to 17, wherein the first connection portion and the active material layer are spaced apart in the first direction.
The battery cell according to any one of claims 3 to 18, wherein the electrode assembly further comprises an insulating member, the insulating member comprising a first insulating portion, the first insulating portion covering a surface of the extension portion facing away from the insulating base, the entire first insulating portion being located between the first solder and the active material layer.
The battery cell of claim 19, wherein the first insulating portion is located between the first connecting portion and the active material layer.

Description

Battery cell, battery device and electricity utilization device Technical Field The application belongs to the technical field of battery energy density, and particularly relates to a battery cell, a battery device and an electricity utilization device. Background Battery cells are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like. The battery device comprises one or more battery cells to meet different electric capacity use requirements, but in the technology of the battery cells, how to improve the energy density of the battery cells is an important research direction. The statements made above merely serve to provide background information related to the present disclosure and may not necessarily constitute prior art. Content of the application An object of an embodiment of the present application is to provide a battery cell, a battery device, and an electric device, including but not limited to, capable of improving the energy density of the battery cell. The technical scheme adopted by the embodiment of the application is as follows: In a first aspect, in some embodiments, a battery cell is provided, the battery cell includes a case provided with an electrode lead-out portion, and an electrode assembly at least partially accommodated in the case, the electrode assembly includes a first electrode sheet including a conductive member, a current collector, and an active material layer, the conductive member is connected to the electrode lead-out portion, the current collector includes an insulating base and a metal layer, the insulating base, the metal layer, and the active material layer are stacked in a thickness direction of the current collector, at least a portion of the metal layer is located between the insulating base and the active material layer, the metal layer includes a conductive portion and an extension portion extending outward from an end of the conductive portion in a first direction, the first direction is perpendicular to the thickness direction of the current collector, the conductive portion is covered with the active material layer, the extension portion is not covered with the active material layer, the conductive member is welded to a surface of the extension portion facing away from the insulating base and forms a first weld, and a distance between the first weld and the active material layer ranges from 0.3mm to 5mm. According to the technical scheme, under the condition that the battery monomer is normally used, the electrode lead-out part is used for inputting or outputting electric energy, charging and discharging of the battery monomer are achieved, the first welding mark and the active material layer are designed to be 0.3 mm-5 mm in interval range, so that the first welding mark cannot be welded to the active material layer, the problems of false welding and the like are reduced, connection reliability of a conductive member and the metal layer is improved, the interval between the active material layer and the first welding mark is small, the active material layer can be relatively close to the first welding mark, more areas can be covered by the active material layer under the condition that the size of the metal layer in the first direction is certain, energy density of the battery monomer is improved, in addition, the current collector adopts a composite structure of an insulating substrate and the metal layer, compared with a pure metal current collector, the thickness of the metal layer is small, burrs generated in the manufacturing process of the current collector are small, internal short circuit of the battery monomer is reduced, use reliability of the battery monomer is improved, and the battery monomer in the embodiment of the application has good reliability and use reliability. In some embodiments, the first solder print and the active material layer have a spacing in the range of 0.5mm to 2.8mm. By adopting the technical scheme of the embodiment, the distance between the active material layer and the first welding mark is more reasonable, and the connection reliability of the conductive member and the energy density of the battery cell can be better considered. In some embodiments, the conductive member includes a first connection portion and at least one second connection portion, the first connection portion and the second connection portion are arranged along a first direction, the first connection portion and the second connection portion are connected, the second connection portion is connected with the electrode lead-out portion, the first connection portion is welded to a surface of the extension portion facing away from the insulating substrate and forms a first solder mark, and the second connection portion is located at a side portion of the extension portion