 Used as the cathode for a lithium-sulfur battery this system has high capacity on the formation of Li2S.In 2014, researchers at USC Viterbi School of Engineering used a graphite oxide coated sulfur cathode to create a battery with 800 mAh/g for 1,000 cycles of charge/discharge, over 5 times the energy density of commercial cathodes.Sulfur is abundant, low cost and has low toxicity.