Patent ID: 6858670

Claim:
A method for preparing solid polymer electrolyte from polyvinyl alcohol, alkaline metal hydroxide and water, comprising the steps of: a) providing a polyvinvl alcohol solution having polyvinyl alcohol with molecular weight between 2,000-120,000 that comprises 10-20% of the whole reactant by weight to mix with water 50-60% by weight under ambient temperature and in a closed environment, and at the same time, providing an alkaline metal hydroxide solution having alkaline metal hydroxide 15-25% by weight to mix with water under ambient temperature and in a closed environment; b) mixing and completely dissolving the polyvinyl alcohol solution and alkaline metal hydroxide solution together under ambient temperature to form a mixture and heating the mixture in a closed container up to 50-100° C. to undergo copolymerization and produce a polymer, and then cooling the polymer in atmosphere; and c) spreading the cooled polymer on a glass fiber cloth and a carrier tray, placing the carrier tray in a temperature/humidity chamber for 30-60 minutes under the temperature of 40-80° C. and humidity of 20-50 RH %, and forming a solid state polymer film.