Plastic PVDF-HFP electrolyte laminates prepared by a phase-inversion process

A method of making microporous separators and laminated plastic Li-ion batt eries which avoids the use of a plasticizer extraction process is described . It is based on phase inversion of PVDF-HFP copolymers via film casting fr om solutions of the copolymer in a mixture of volatile solvent and non-solv ent. The electrode and separator films so obtained exhibit a high electroly te uptake and allow the fabrication of laminated plastic Li-ion batteries w ith good discharge rate capabilities. The unique and unexpected pole morpho logy obtained by the described process is illustrated by SEM microphotograp hs. Its effect on the mechanical stability of the microporous structure, wh ich enables excellent bonding of the various layers via lamination under el evated temperature and pressure without destruction of the porosity, is dis cussed as well. (C) 2000 Published by Elsevier Science B.V.