Grafted microporous separator for electrochemical generator and a process for its production

摘要

A separator for an electrochemical generator is constituted by a microporous polyolefin film grafted with at least one monomer selected from diethyleneglycol dimethacrylate, furfuryl acrylate and a diethyleneglycol dimethacrylate/acrylic acid mixture. In a process for the production of a separator of this kind grafting of the monomer is carried out in three stages: irradiation of the film, if required, storage of the irradiated film, immersion of the irradiated film in the grafting solution comprising the monomer, a solvent, and at least one additive. The separator may be used in an electrochemical generator with either an aqueous or nonaqueous electrolyte where the salt concentration is between 1M and 2M.