Characteristics of gel alkylene oxide polymer electrolytes containing γ-butyrolactone

Gel polymer electrolytes consisted of poly(alkylene oxide) (PAO), LiBF4 or LiClO4, and aprotic solvents (γ-butyrolactone (GBL) and/or ethylene carbonate (EC)) were prepared and the conductivity was measured. The conductivity was very high and similar to that of the organic liquid electrolytes. The performance of Li gel polymer electrolyte LiCoO2 cell was measured and compared to that of the cell with the liquid electrolyte corresponded. The cell with the gel electrolyte showed a decrease of capacity at high-rate discharge and low temperature owing to concentration polarization.