CHEMICAL OXIDATION - A ROUTE TO ENHANCED CAPACITY IN LI-ION GRAPHITE ANODES

Chemical oxidation of graphite powder by the strong oxidative agents a mmonium peroxysulfate and hot, concentrated nitric acid was examined a s a way to enhance the capacity of graphite anodes in Li-ion cells. Ch emical oxidation increased the reversible capacity obtained during cyc ling from 370 to 430 mAh/g, whereas the irreversible capacity accompan ying the first intercalation cycle was reduced. Fourier transform infr ared spectroscopy was used to investigate the effects of chemical oxid ation on the surface of the graphite. Slow-scan cyclic voltammetry was applied in order to detect the origin of the extra capacity (where x > 1 in LixC6) associated with oxidized graphite powder.