Electrolyte Additives for High Voltage Lithium Ion Batteries

A group of electrolyte additives are selected for high voltage lithium ion batteries based on the concepts that the additives are oxidized preferably to solvents and subsequently protective films can be formed on cathodes. The oxidation probability of the selected additive is understood with theoretical calculations and their influences on cathode performances of high voltage lithium ion battery are investigated via physical and electrochemical characterizations. The selected additives involve the molecules that contain aromatic ring, sulfur, phosphor, nitrogen and or fluorine. The cathode materials that the selected additives are used for include spinel nickel manganese oxide, layer nickel, cobalt and manganese oxides and layered lithium-rich manganese oxide. The effects of the selected additives on graphite anode are also considered.