Battery cell, battery, and electric apparatus

Abstract

Embodiments of this application provide a battery cell, a battery, and an electric apparatus. The battery cell may include an electrode assembly, a housing, an electrode terminal, and a current collector. The electrode assembly may include a first tab. The housing may be configured to accommodate the electrode assembly. The electrode terminal may be disposed in the housing, and the electrode terminal may include a first concave portion and a connecting portion at the bottom of the first concave portion. The current collector may be connected to the first tab and welded to the connecting portion.

1 . A battery cell, comprising:
 an electrode assembly, comprising a first tab;   a housing, configured to accommodate the electrode assembly;   an electrode terminal, disposed on the housing, the electrode terminal comprising a first concave portion and a connecting portion at the bottom of the first concave portion; and   a current collector, connected to the first tab and welded to the connecting portion.   
     
     
         2 . The battery cell according to  claim 1 , wherein the current collector is welded to the connecting portion to form a first welding portion, and in a thickness direction of the connecting portion, the first welding portion extends from a side of the connecting portion facing away from the current collector at least to the inside of the current collector. 
     
     
         3 . The battery cell according to  claim 2 , wherein in the thickness direction of the connecting portion, the first welding portion does not protrude beyond a surface of the current collector facing away from the connecting portion. 
     
     
         4 . The battery cell according to  claim 2 , wherein the housing comprises a cylinder and a cover connected to the cylinder, the cylinder is disposed around the periphery of the electrode assembly, the cover is provided with an electrode lead-out hole, and the electrode terminal is mounted in the electrode lead-out hole;
 the first welding portion and the cover are both annular, outer diameter of the cover is D 0 , and inner diameter of the first welding portion is D 1 ; and   D 1  and D 0  satisfy 0.1≤D 1 /D 0 ≤0.6.   
     
     
         5 . The battery cell according to  claim 4 , wherein the first welding portion is a non-closed structure, and a central angle of the first welding portion ranges from 180° to 330°. 
     
     
         6 . The battery cell according to  claim 4 , wherein the first welding portion is a closed structure. 
     
     
         7 . The battery cell according to  claim 4 , wherein 0.2≤D 1 /D 0 ≤0.4. 
     
     
         8 . The battery cell according to  claim 4 , wherein D 1  ranges from 5 mm to 14 mm. 
     
     
         9 . The battery cell according to  claim 4 , wherein the cover and the cylinder are integrally formed. 
     
     
         10 . The battery cell according to  claim 2 , wherein in the thickness direction of the connecting portion, a dimension of the first welding portion is h, and a thickness of a region of the connecting portion for welding with the current collector is d 0 ; and
 d 0  and h satisfy 1<h/d 0 ≤1.5.   
     
     
         11 . The battery cell according to  claim 10 , wherein a thickness of a region of the current collector for welding with the connecting portion is d 1 , and d 0  and d 1  satisfy 0.5≤d 1 /d 0 ≤1.2. 
     
     
         12 . The battery cell according to  claim 10 , wherein do ranges from 0.4 mm to 1.2 mm. 
     
     
         13 . The battery cell according to  claim 1 , wherein at least part of the first tab is located on a side of the current collector facing away from the electrode terminal and supports the current collector. 
     
     
         14 . The battery cell according to  claim 13 , wherein a first portion of the first tab is located on a side of the connecting portion facing away from the first concave portion, and is configured to support part of the current collector that is opposite the connecting portion. 
     
     
         15 . The battery cell according to  claim 14 , wherein the first portion is welded to the current collector to form a second welding portion. 
     
     
         16 . The battery cell according to  claim 13 , wherein a second portion of the first tab encloses the periphery of the first portion, and is configured to support a region of the current collector that is not opposite the connecting portion. 
     
     
         17 . The battery cell according to  claim 16 , wherein the second portion is welded to the current collector to form a third welding portion. 
     
     
         18 . The battery cell according to  claim 17 , wherein the current collector has a convex portion on a side facing the first tab, and the convex portion is welded to the second portion to form the third welding portion. 
     
     
         19 . The battery cell according to  claim 17 , wherein the first tab is disposed around the central axis of the electrode assembly, and a cross section of the first tab perpendicular to the central axis is annular; and
 an outer radius of the first tab is R, a minimum distance from the third welding portion to the central axis in the radial direction of the first tab is D 2 , and R and D 2  satisfy 0.2≤D 2 /R≤0.8.   
     
     
         20 . The battery cell according to  claim 19 , wherein D 2  and R satisfy 0.2≤D 2 /D 2 ≤0.5. 
     
     
         21 . The battery cell according to  claim 19 , wherein D 2  ranges from 3.5 mm to 10 mm. 
     
     
         22 . The battery cell according to  claim 13 , wherein a diameter of the current collector is D 3 , a diameter of the first tab is D 4 , and D 3  is less than D 4 . 
     
     
         23 . The battery cell according to  claim 22 , wherein D 3  and D 4  satisfy 0.75≤D 3 /D 4 ≤0.97. 
     
     
         24 . The battery cell according to  claim 22 , wherein D 3  ranges from 35 mm to 44 mm. 
     
     
         25 . The battery cell according to  claim 2 , wherein the connecting portion is provided with a groove recessed from a first outer surface of the connecting portion in a direction facing the electrode assembly, and the first welding portion extends from the bottom wall of the groove at least to the inside of the current collector. 
     
     
         26 . The battery cell according to  claim 1 , wherein
 the housing comprises a cylinder and a cover connected to the cylinder, the cylinder is provided around the periphery of the electrode assembly, the cover is provided with an electrode lead-out hole, and the electrode terminal is mounted in the electrode lead-out hole; and   the electrode terminal comprises a terminal body, the terminal body comprises a columnar portion, a first restraint structure, and a second restraint structure, at least part of the columnar portion is located in the electrode lead-out hole, the first concave portion is disposed in the columnar portion, the first restraint structure and the second restraint structure are both connected to and protrude from the outer lateral wall of the columnar portion, and the first restraint structure and the second restraint structure are disposed on the outside and inside of the cover respectively and together are configured to clamp part of the cover.   
     
     
         27 . The battery cell according to  claim 26 , wherein the terminal body has a second outer surface, and the first concave portion is recessed from the second outer surface in the direction facing the electrode assembly to the first outer surface of the connecting portion. 
     
     
         28 . The battery cell according to  claim 26 , wherein the electrode terminal further comprises a sealing plate, and the sealing plate is connected to the terminal body and seals an opening of the first concave portion. 
     
     
         29 . The battery cell according to  claim 1 , wherein the electrode assembly further comprises a second tab with a polarity opposite to that of the first tab, and the second tab is disposed around the central axis of the electrode assembly; and
 the first tab is disposed at an end of the electrode assembly facing the electrode terminal, the second tab is disposed at an end of the electrode assembly facing away from the electrode terminal, and the second tab is electrically connected to the housing.   
     
     
         30 . The battery cell according to  claim 29 , wherein the second tab is a negative electrode tab, and a substrate material of the housing is steel. 
     
     
         31 . The battery cell according to  claim 1 , wherein the housing has an opening at an end facing away from the electrode terminal, and the battery cell further comprises a cover plate for sealing the opening. 
     
     
         32 . A battery, comprising the battery cell according to  claim 1 . 
     
     
         33 . An electric apparatus, comprising the battery according to  claim 32 , wherein the battery is configured to supply electrical energy.