Method for manufacturing safety vent on cover of lithium-ion battery

Abstract

A method for manufacturing a safety vent on a cover of a lithium-ion battery has punching the cover to form an annular recess and the cover made of aluminum alloy; heating the annular recess to a temperature between 200° C.˜500° C.; cooling the annular recess; and obtaining the safety vent on the cover of the lithium-ion battery. The aluminum alloy can be heated to a specific temperature for lowering its stress, so a thickness between a lower surface of the cover and a bottom of the annular recess is neither necessary to be precisely controlled, so retaining yield of lithium-ion batter

1 . A method for manufacturing a safety vent on a cover of a lithium-ion battery comprising:
 punching the cover to form an annular recess and the cover made of aluminum alloy;   heating the annular recess to a temperature between 200° C.˜500° C.;   cooling the annular recess; and   obtaining the safety vent on the cover of the lithium-ion battery.   
     
     
         2 . The method as claimed in  claim 1 , wherein in the step of punching the cover to form an annular recess, a thickness between a lower surface of the cover and a bottom of the annular recess is between 0.05 mm and 0.07 mm. 
     
     
         3 . The method as claimed in  claim 1 , wherein in the step of heating the annular recess, the annular recess is heated to a temperature of 400° C. 
     
     
         4 . The method as claimed in  claim 2 , wherein in the step of heating the annular recess, the annular recess is heated to a temperature of 400° C. 
     
     
         5 . The method as claimed in  claim 1 , wherein the steps of heating the annular recess and cooling the annular recess forms a step of annealing the annular recess, which is performed after the step of punching the cover. 
     
     
         6 . The method as claimed in  claim 2 , wherein a step of annealing the annular recess having the steps of heating the annular recess and cooling the annular recess are performed after the step of punching the cover. 
     
     
         7 . The method as claimed in  claim 3 , wherein a step of annealing the annular recess having the steps of heating the annular recess and cooling the annular recess are performed after the step of punching the cover. 
     
     
         8 . The method as claimed in  claim 4 , wherein a step of annealing the annular recess having the steps of heating the annular recess and cooling the annular recess are performed after the step of punching the cover.