TECHNOLOGY FOCUS - POLYMERS - Preferred Polymer: The oxyalkylene-containing group is introduced by the reaction of a polymer compound containing the polyvinyl alcohol units with one or more oxirane compounds of ethylene oxide, propylene oxide and glycidol, or by reacting with a polyoxyalkylene compound with a substituent having reactivity towards the terminal hydroxyl groups on the polyvinyl alcohol unit-containing polymer compound in which the reactive substituent can be isocyanate group, epoxy group, carboxy group, acid chloride group, ester group, amide group, halogen, or silicon-containing group.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.Preferred Resin Binder And Composition: The resin binder and composition have 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 parts wt.) in acetone was treated with sodium hydroxide aqueous solution then with glycidol (67 parts wt.) to give a dihydroxypropylated polyvinyl alcohol in a yield of 22.5 parts 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. Properties of the composition: ion conductivity = 5.2 x 10-4 S/cm; bonding strength = 0.74 kN/m; non crystalline; rubbery solid at room temperature; and not more than 0.1% weight loss by vaporization.