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

• Published in: Solid state ionics Vol. 135; no. 1; pp. 249 - 257
• Main Authors: Du Pasquier, A., Warren, P.C., Culver, D., Gozdz, A.S., Amatucci, G.G., Tarascon, J.-M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-11-2000; Elsevier Science
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Lithium-ion; Microporosity; Phase inversion; Polymer battery; PVDF-HFP copolymers; Phase inversion; PVDF-HFP copolymers; Polymer battery; Microporosity; Lithium-ion; Vinylidene fluoride copolymer; Manufacturing process; Battery; Polymer solid electrolyte; Secondary cell; Porous material; Lithium ion; Separator
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/S0167-2738(00)00371-4

A method of making microporous separators and laminated plastic Li-ion batteries which avoids the use of a plasticizer extraction process is described. It is based on phase inversion of PVDF-HFP copolymers via film casting from solutions of the copolymer in a mixture of volatile solvent and non-solvent. The electrode and separator films so obtained exhibit a high electrolyte uptake and allow the fabrication of laminated plastic Li-ion batteries with good discharge rate capabilities. The unique and unexpected pore morphology obtained by the described process is illustrated by SEM microphotographs. Its effect on the mechanical stability of the microporous structure, which enables excellent bonding of the various layers via lamination under elevated temperature and pressure without destruction of the porosity, is discussed as well.