TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: Some or all of the remaining hydroxyl groups on the polyvinyl alcohol units in the polymer compound can be blocked with halogen, 1-10C (un)substituted monovalent hydrocarbyl, R1CO- group (where R1 = 1-10C (un)substituted monovalent hydrocarbyl), R13Si-group, amino, alkylamino or/and phosphorus-containing group, particularly 1 or more of the blocking groups is cyanoethylated monovalent hydrocarbyl. Bonding strength of the composition is not less than 0.1 kN/m as determined by JIS K6854 (1994). Preferred Binder Resin: The binder resin has a bonding strength of not less than 0.1 kN/m as determined by JIS K6854 (1994). Preferred Batteries: Such batteries are fabricated with a layer of a solid electrolyte polymer made from the composition for ionically conductive polymer electrolyte. The resin binder can be used to made a composite positive electrode together with a positive electrode active material and dopant solution for coating onto the positive electrode current collector body, and similarly the binder is also applicable in producing a lithium foil-based negative electrode with a coating of the composition for ionically conductive polymer electrolyte. EXAMPLE - Polyvinyl alcohol (average polymerization degree = 500, and vinyl alcohol fraction = not less than 98%; 10 pts.wt.) in acetone was treated with sodium hydroxide aqueous solution then with glycidol (67 pts.wt.) to give a dihydroxypropylated polyvinyl alcohol in a yield of 22.5 pts.wt. which was cyanoethylated by treatment with acrylonitrile and aqueous sodium hydroxide. A composition for ionically conductive polymer electrolyte was formulated from the cyanoethylated polymer derivative and lithium perchlorate, followed by adding polyethylene glycol dimethacrylate (oxyethylene units = 9) as crosslinking agent (1), methoxypolyethylene glycol monomethacrylate (oxyethylene units = 9) as crosslinking agent (2) and azobisisobutyronitrile. Properties of the compositon: ion conductivity = 4.2 x 10-4 S/cm; bonding strength = 0.8 kN/m; non crystalline; solid at room temperature; and not more than 0.1% weight loss by vaporisation.