Effect of processing parameters on the electrochemical properties of a polymer electrolyte prepared by the phase inversion process

Abstract

Porous polymer membranes based on poly(vinylidene fluoride-co-hexafluoropropylene) were prepared by the phase inversion process, and the effect of processing parameters, such as the type of solvent and concentration of the polymer solution, on the membrane morphology and electrochemical properties of a polymer electrolyte (PE) was investigated. The membranes prepared were characterized by scanning electron microscopy and differential scanning calorimetry. PEs were prepared by soaking the porous membrane in 1 M LiPF(6) in ethylene carbonate/dimethyl carbonate, and their electrochemical performance was studied. The polymer concentration and/or non-solvent greatly influenced the morphology and electrochemical performance of the PE. A conductivity of similar to 10(-3) S cm(-1) and charge/discharge capacities of similar to 140 mAh g(-1) for the Li/LiFePO(4) cell were obtained.