ELECTROLYTIC MEMBRANE, METHOD OF MANUFACTURING IT AND USE

摘要

PURPOSE: Provided is electrolytic membrane comprising an ion-conducting polymer which is fixed in the pores of a porous polyalkene membrane stretched in at least one direction. CONSTITUTION: A polyalkene membrane has a porosity of 30-90 % and a mean pore diameter of 0.1 to 5.0μm. The elctrolytic membrane can be manufactured by impregnating the polyalkene with a suitable solution of the ion-conducting polymer at a temperature which is at least 80°C, preferably at least 110°C, and which is not above the melting point of the polyalkene membrane used. The electrolytic membrane is very suitable for use in solid-polymer fuel cells and batteries. Method of manufacturing an electrolytic membrane which comprises the following steps: a) dissolving an ion-conducting polymer in a solvent, at least 25% by weight of which is composed of a component having a boiling point higher than 125°C, b) applying an amount of the solution prepared under (a) to a horizontal polyalkene membrane stretched in at least one direction and having a pore volume of 30-90% of the total volume of the membrane, the amount of the solution being chosen in such a way that the volume of the ion-conducting polymer present therein is more than 60% of the pore volume, and the membrane being sealed at the underside, c) evaporating the solvent at a temperature which is at least 80°C and which is lower than the melting point of the polyalkene membrane.