Secondary battery and method of manufacturing the secondary battery

Abstract

The present disclosure relates to a secondary battery and a method of manufacturing the secondary battery. The secondary battery includes: a case; an electrode assembly, accommodated in the case and including a main body and a tab connected to the main body; a cap plate, coupled to the case; an electrode terminal, located on an outer side of the cap plate and including a first metal layer and a second metal layer disposed one on top of another; and a current collecting member, connected between the tab and the electrode terminal.

What is claimed is: 
     
         1 . A secondary battery, comprising:
 a case;   an electrode assembly, accommodated in the case and comprising a main body and a tab connected to the main body;   a cap plate, coupled to the case and comprising an electrode lead-out hole;   an electrode terminal, covering the electrode lead-out hole of the cap plate and provided with a first through hole; and   a current collecting member, connected between the tab and the electrode terminal, wherein the current collecting member comprises an extending portion extending toward the electrode terminal and protruding into the first through hole, the extending portion is connected to the electrode terminal and is exposed to a side of the electrode terminal facing away from the cap plate.   
     
     
         2 . The secondary battery according to  claim 1 , wherein the electrode terminal comprises a first metal layer and a second metal layer disposed one on top of another, the second metal layer is located on a side of the first metal layer away from the cap plate, and the first metal layer and the second metal layer are made of different materials, and wherein the first through hole is a stepped hole and the stepped hole comprises a first hole segment penetrating through the first metal layer and a second hole segment penetrating through the second metal layer and extending into the first metal layer, the extending portion protrudes into the first hole segment and is directly connected to the first metal layer, and the first metal layer is made of the same material as the current collecting member. 
     
     
         3 . The secondary battery according to  claim 2 , wherein,
 both of the first metal layer and the current collecting member are made of copper, and the second metal layer is made of aluminum.   
     
     
         4 . The secondary battery according to  claim 2 , wherein,
 both of the first metal layer and the current collecting member are made of aluminum, and the second metal layer is made of copper.   
     
     
         5 . The secondary battery according to  claim 2 , wherein the second hole segment has a diameter larger than that of the first hole segment, and the extending portion is welded to the first metal layer. 
     
     
         6 . The secondary battery according to  claim 5 , wherein the second hole segment includes a sink portion disposed in the first metal layer, and a top surface of the extending portion is flush with a bottom surface of the sink portion. 
     
     
         7 . The secondary battery according to  claim 5 , wherein the extending portion and the first metal layer are welded to each other, by which an annular welding seam is formed so as to connect the extending portion and the first metal layer in a sealed manner. 
     
     
         8 . The secondary battery according to  claim 2 , wherein a composite connection interface is formed between the first metal layer and the second metal layer, and the secondary battery further comprises a connecting member abutting against the second metal layer and forming a contact interface together with the second metal layer, wherein the contact interface is located above the composite connection interface. 
     
     
         9 . The secondary battery according to  claim 1 , wherein the current collecting member further comprises a connecting portion connected to the extending portion, the connecting portion is located on an inner side of the cap plate and directly connected to the tab, and the connecting portion is formed in a sheet-like shape and is made of the same material as the tab. 
     
     
         10 . The secondary battery according to  claim 9 , wherein the current collecting member further comprises a projection connected between the extending portion and the connecting portion, and a recess is formed on a side of the projection away from the electrode terminal by forming the projection. 
     
     
         11 . The secondary battery according to  claim 10 , wherein the extending portion, the projection and the connecting portion are formed into an integral member. 
     
     
         12 . The secondary battery according to  claim 10 , wherein the projection is provided with a second through hole, and the extending portion is adapted to pass through the second through hole; and the current collecting member further comprises a support portion connected with the extending portion, and the support portion is accommodated in the recess. 
     
     
         13 . The secondary battery according to  claim 12 , wherein the support portion is adapted to extend beyond an inner wall of the second through hole in a radial direction of the second through hole. 
     
     
         14 . The secondary battery according to  claim 13 , wherein the projection is clamped by the support portion and the electrode terminal together. 
     
     
         15 . The secondary battery according to  claim 10 , wherein the secondary battery further comprises an insulating member disposed on the inner side of the cap plate, the insulating member is located between the connecting portion of the current collecting member and the cap plate and surrounds the projection of the current collecting member in a circumferential direction, so as to electrically insulate the current collecting member from the cap plate. 
     
     
         16 . The secondary battery according to  claim 1 , wherein the extending portion is formed as a hollow cylindrical member having a blind hole, and the blind hole is provided with an opening toward the electrode assembly. 
     
     
         17 . A battery module, comprising:
 a plurality of secondary batteries according to  claim 1 .   
     
     
         18 . A battery pack, comprising:
 at least one battery module according to  claim 17 .   
     
     
         19 . An apparatus using a secondary battery as a power source, wherein,
 the secondary battery is a secondary battery according to  claim 1 .   
     
     
         20 . A method of manufacturing a secondary battery, comprising steps of:
 providing a current collecting member, wherein the current collecting member comprises an extending portion;   providing an electrode terminal and a cap plate, wherein the cap plate is provided with an electrode lead-out hole and the electrode terminal covers the electrode lead-out hole of the cap plate and is provided with a first through hole;   inserting the extending portion into the first through hole from an inner side of the cap plate; and   performing laser welding from an outer side of cap plate so as to weld the extending portion to the electrode terminal by the laser welding.