Lithium secondary battery

Abstract

A lithium secondary battery contains an electrode body obtained by winding a positive electrode and a negative electrode via a separator, a non-aqueous electrolytic solution, and a battery case accommodating the electrode body and the non-aqueous electrolytic solution. A lid and a metal foil are adhered to each other with a resin to form a pressure-releasing valve and make air-tight the inside of the battery case. This secondary battery is easy to produce and has excellent operational safety and excellent reliability.

What is claimed is:  
     
         1 . A lithium secondary battery comprising: an electrode body obtained by winding or laminating a positive electrode and a negative electrode via a separator; and a non-aqueous electrolytic solution, 
 wherein at least one metal foil and at least one resin film are provided in layers to seal the non-aqueous electrolytic solution.    
     
     
         2 . A lithium secondary battery according to  claim 1 , wherein the at least one resin film faces an interior of the battery.  
     
     
         3 . A lithium secondary battery according to  claim 1 , wherein the at least one metal foil and the at least one resin film are adhered to each other.  
     
     
         4 . A lithium secondary battery according to  claim 1 , wherein the at least one metal foil is coated with the at least one resin film.  
     
     
         5 . A lithium secondary battery according to  claim 1 , wherein the at least one metal foil comprises at least one metal selected from the group consisting of Al, Cu, and Ni.  
     
     
         6 . A lithium secondary battery according to  claim 1 , wherein the at least one resin film comprises at least one resin selected from the group consisting of polyethylene, polypropylene, polyamides and fluororesins.  
     
     
         7 . A lithium secondary battery according to  claim 1 , wherein the electrode body and the non-aqueous electrolytic solution are contained within at least one lid and a battery case.  
     
     
         8 . A lithium secondary battery according to  claim 7 , wherein a hole formed on the lid or on the case, is closed with the at least one metal foil and the at least one resin film.  
     
     
         9 . A lithium secondary battery according to  claim 8 , wherein the hole functions as a pressure-releasing hole.  
     
     
         10 . A lithium secondary battery according to  claim 8 , wherein the at least one metal foil and the at least one resin film together constitute a pressure releasing valve.  
     
     
         11 . A lithium secondary battery according to  claim 1 , wherein said at least one metal foil consists of a single metal foil, and said at least one resin film consists of a single resin film in contact with said single metal foil.  
     
     
         12 . A lithium secondary battery according to  claim 1 , wherein said at least one metal foil consists of a single metal foil having a first side and a second side, and said at least one resin film consists of a first resin film and a second resin film, said first resin film being in contact with said first side of said metal foil, said second resin film being in contact with said second side of said metal foil.