Effect of fillers on the electrochemical and interfacial properties of PEO-LiN(SO2CF2CF3)2 polymer electrolytes

The effect of nano-sized silica and gamma-LiAIO(2) on the electrochemical and interfacial properties of P(EO)(20)LiN(SO2CF2CF3)(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)(20)LiBETI polymer electrolytes at 90degreesC 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 90degreesC. For the galvanostatic Li stripping/deposition at 0.2 mA/cm(2) at 90degreesC, 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)(20)LiBETI polymer electrolytes results in no substantial improvement on the electrochemical and interfacial properties of the electrolytes at 90degreesC. (C) 2003 Elsevier Ltd. All rights reserved.