Lithium Secondary Battery and Secondary Battery Sub Module Comprising the Same

Abstract

The present invention provides a lithium secondary battery and a lithium secondary battery sub module including the same. The lithium secondary battery includes: an electrode assembly; a plastic case which houses the electrode assembly and includes a gas barrier layer; and a pouch film cover which seals the plastic case having the electrode assembly housed therein, such that it is possible to achieve a battery having a significantly increased thickness so as to increase the capacity thereof without structural limitation, secure durability of the battery due to having excellent resistance to permeability, and improve productivity due to a decrease in an occurrence of poor insulation. Thereby, the lithium secondary battery sub module including the lithium secondary battery may have a high energy density and may be formed in a compact shape with reduced manufacturing costs.

What is claimed is: 
     
         1 . A lithium secondary battery comprising:
 an electrode assembly;   a plastic case which houses the electrode assembly and includes a gas barrier layer; and   a pouch film cover which seals the plastic case having the electrode assembly housed therein.   
     
     
         2 . The lithium secondary battery according to  claim 1 , wherein the plastic case is made of at least one selected from a group consisting of polyethylene, polypropylene, polyethylene terephthalate and polyethylene naphthalate. 
     
     
         3 . The lithium secondary battery according to  claim 1 , wherein the plastic case is injection mold. 
     
     
         4 . The lithium secondary battery according to  claim 1 , wherein the gas barrier layer includes at least one selected from a group consisting of ethylene-vinyl alcohol copolymer; polyvinylidene chloride; polyvinyl alcohol; nylon; polyamide; polyacrylonitrile, linear low-density polyethylene, ethylene-vinyl alcohol copolymer, and ionomer copolymer; a metal film; a coating layer made of at least one selected from a group consisting of silica, alumina, rubber, metal, glass and amorphous carbon; and a film having a coating layer in which layered silicate nano particles are dispersed in a polyvinyl alcohol binder. 
     
     
         5 . The lithium secondary battery according to  claim 1 , wherein the gas barrier layer is formed on an inner surface of the plastic case. 
     
     
         6 . The lithium secondary battery according to  claim 1 , wherein the plastic case is formed in a plurality of layers, and the gas barrier layer is included in an inner layer of the plastic case. 
     
     
         7 . The lithium secondary battery according to  claim 1 , wherein the pouch film cover is a stacked film including an inner resin layer, a metal thin film and an outer resin layer. 
     
     
         8 . The lithium secondary battery according to  claim 1 , wherein the inner resin layer contacting with the plastic case of the pouch film cover is made of the same material as the plastic case. 
     
     
         9 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 1 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         10 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 2 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         11 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 3 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         12 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 4 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         13 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 5 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         14 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 6 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         15 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 7 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.   
     
     
         16 . A lithium secondary battery sub module comprising:
 a heat radiation plate; and   the lithium secondary batteries according to  claim 8 , which are respectively disposed on both side of the heat radiation plate,   wherein the respective lithium secondary batteries are disposed so that the pouch film covers face the heat radiation plate.