Effect of fillers on the electrochemical and interfacial properties of PEO–LiN(SO 2CF 2CF 3) 2 polymer electrolytes

Abstract

The effect of nano-sized silica and γ-LiAlO 2 on the electrochemical and interfacial properties of P(EO) 20LiN(SO 2CF 2CF 3) 2–10 wt.% filler polymer electrolytes has been studied using linear sweep voltammetry, ac impedance and galvanostatic stripping/deposition on symmetric non-blocking cells. Non-symmetric cells were used to investigate the electrochemical stability window. The limiting current density of the P(EO) 20LiBETI polymer electrolytes at 90 °C was found to decrease with the addition of nano-sized filler. The presence of silica caused higher interface resistance during storage in open circuit at 90 °C. For the galvanostatic Li stripping/deposition at 0.2 mA/cm 2 at 90 °C, the silica containing electrolyte showed the highest initial overvoltage due to the high interface resistance. These results suggest that the presence of nano-size silica in solvent-free P(EO) 20LiBETI polymer electrolytes results in no substantial improvement on the electrochemical and interfacial properties of the electrolytes at 90 °C.