A gel polymer electrolyte (GPE) was prepared using tetra(ethylene glycol) diacrylate monomer, benzoyl peroxide, and 1.0 M LiPF6/EC-DEC (1 : 1 vol%). The LiCoO2/GPE/graphite cells were prepared and their electrochemical properties were evaluated at various current densities and temperatures. The viscosity of the precursor containing the 5 vol% tetra(ethylene glycol) diacrylate monomer was around 4.6 mPa s. The ionic conductivity of the gel polymer electrolyte at 20degreesC was around 5.9 x 10(-3) S cm(-1). The gel polymer electrolyte had good electrochemical stability up to 4.3 V vs. Li/Li+. The capacity of the LiCoO2/GPE/graphite cell at 2.0 C rate was 63% of the discharge capacity at 0.2 C rate. The capacity of the cell at -10degreesC was 81% of the discharge capacity at 20degreesC. Discharge capacity of the cell with gel polymer electrolyte was stable with charge-discharge cycling. (C) 2003 Elsevier Science Ltd. All rights reserved.