(JP2872223-B2)      Vinylacetate copolymer for a gel polymer electrolyte compsn. usable in a L i-secondary cell comprises a cpd. of formula (1). R1 = H or CH3; R2 = a gp. of formula -COOR3 (2) or 1-pyrrolidone; m,n = integer, ratio m/n is (50-99)/(1-50). Gel polymer electrolyte compsn. comprises the copolymer 20-30 w t%, inorganic filler 5-20 wt% and an electrolyte soln. (Li-salt dissolved in a non-protonic solvent) 60-80 wt%. Also claimed is a vinylacetate copolymer for a gel polymer electrolyte compsn. usable in a Li-secondary cell comprises a cpd. of formula (3). A = carbonyl gp. of formula -CO- (4) or maleic anhydride gp. of formula (5); x,y,z = integer, ratio of x/y/z -s (60-90)/(10-40)/(0-20).    USE -   Used in Li-secondary cell.    ADVANTAGE -   Product has high ion conductivity.    (CA2237705-A)      NOVELTY - Vinyl acetate copolymers (I) may be used in the gel polymer electrolyte of a lithium secondary cell.    DETAILED DESCRIPTION - A vinyl acetate copolymer for use in the gel polymer electrolyte of a lithium secondary cell has the formula (I). R1 = H or methyl; R2 = -C(O)O-alkyl or 1-pyrrolidone; alkyl = methyl, ethyl, propyl, isopropyl or butyl; and m, n = integers with a ratio m:n of 50-99:1-50.    INDEPENDENT CLAIMS are also included for: (a) a copolymer for use as the gel polymer electrolyte of a lithium secondary cell having the formula (II); and (b) gel polymer electrolyte compositions for use in a lithium secondary cell comprising copolymer (I) or (II) (20-30 wt.%), an inorganic filler (5-20 wt.%) and a solution of a lithium salt in an aprotic solvent (60-80 wt.%). A = carbonyl or a maleic anhydride group (a); and x, y, z = integers with a ratio x:y:z of 60-90:10-40:0-20    USE -   In the polymer electrolyte composition of a lithium secondary cell (claimed), e.g. for electrical, electronic, telecommunication or computer applications.    ADVANTAGE -   The copolymers provide polymer electrolytes with a high film-forming property, good electrolyte containment and adhesive properties (to the anode and cathode), and cells with good methanical strength are prepared easily. The copolymers contain groups which make them compatible with liquid organic electrolytes. An organic electrolyte in a matrix of the polymer is stable and resistant to loss of the organic liquid, it has a high ionic conductivity, and it can be prepared easily at room temperature.    (US6268088-B1)      Vinylacetate copolymer for a gel polymer electrolyte compsn. usable in a L i-secondary cell comprises a cpd. of formula (1). R1 = H or CH3; R2 = a gp. of formula -COOR3 (2) or 1-pyrrolidone; m,n = integer, ratio m/n is (50-99)/(1-50). Gel polymer electrolyte compsn. comprises the copolymer 20-30 w t%, inorganic filler 5-20 wt% and an electrolyte soln. (Li-salt dissolved in a non-protonic solvent) 60-80 wt%. Also claimed is a vinylacetate copolymer for a gel polymer electrolyte compsn. usable in a Li-secondary cell comprises a cpd. of formula (3). A = carbonyl gp. of formula -CO- (4) or maleic anhydride gp. of formula (5); x,y,z = integer, ratio of x/y/z -s (60-90)/(10-40)/(0-20).    USE -   Used in Li-secondary cell.    ADVANTAGE -   Product has high ion conductivity.