Preparation and electrochemical performance of gel polymer electrolytes using tri(ethylene glycol) dimethacrylate

A gel polymer electrolyte (GPE) is prepared from tri(ethylene glycol) dimethacrylate monomer, benzoyl peroxide, and 1.0 M LiPF6/ethylene carbonate:diethyl carbonate (1:1 vol.%). The LiCoO2graphite cells are assembled and their electrochemical properties are evaluated at various current densities and temperatures. The viscosity of the precursor containing 5 vol.% tri(ethylene glycol) dimethacrylate monomer is around 4.6 mPa s. The ionic conductivity of the gel polymer electrolyte at 20 °C is around 5.9×10−3 S cm−1. The gel polymer electrolyte has good electrochemical stability up to 4.5 V versus Li/Li+. The capacity of the cell at the 1.0 C rate is 89% of the discharge capacity at the 0.2 C rate. The capacity of the cell at temperature of −10 °C is 81% of the discharge capacity at 20 °C. The discharge capacity of the cell with gel polymer electrolyte is stable with charge–discharge cycling.