Towards Li-Ion Batteries Operating At 80 Degrees C: Ionic Liquid Versus Conventional Liquid Electrolytes

Li-ion battery (LIB) full cells comprised of TiO2-nanotube (TiO2-nt) and LiFePO4 (LFP) electrodes and either a conventional organic solvent based liquid electrolyte or an ionic liquid based electrolyte have been cycled at 80 degrees C. While the cell containing the ionic liquid based electrolyte exhibited good capacity retention and rate capability during 100 cycles, rapid capacity fading was found for the corresponding cell with the organic electrolyte. Results obtained for TiO2-nt and LFP half-cells indicate an oxidative degradation of the organic electrolyte at 80 degrees C. In all, ionic liquid based electrolytes can be used to significantly improve the performance of LIBs operating at 80 degrees C.