Perpustakaan Digital ITB

For the application of lithium-ion batteries (LiBs) to a large-scalepower source for electric vehicles, positive electrode materials with high energyand power densities should be developed. Although Li-excess materials areregarded as high-capacity positive electrodes, there are several issues in the anionicredox reactions, such as oxygen gas evolution and large resistance, which lead tocapacity fading and limitation of high-current operation. Here, we report the high-current operation of an electrochemical cell using the Li2RuO3?Li2SO4positiveelectrode in LiBs. The cell using Li2Ru0.8S0.2O3.2showed a high capacity of 350mAh g?1with an average discharge voltage of 2.9 V vs Li at 25°C. By introducingan amorphous matrix based on Li2SO4, a high diffusion coefficient was maintained during the whole charge?discharge process,and low charge-transfer resistance was maintained even at a high oxidation state up to 4.2 V vs Li. As a result, extremely highcurrent operation, such as 40 C rate, was achieved.