Realizing High Voltage Lithium Cobalt Oxide in Lithium-Ion Batteries

The combination of high voltage cathode and metal or graphite anodes provides a feasible way for future high-energy batteries. Among various battery cathodes, lithium cobalt oxide is outstanding for its excellent cycling performance, high specific capacity, and high working voltage and has achieved great success in the field of consumer electronics in the past decades. Recently, demands for smarter, lighter, and longer standby-time electronic devices have pushed lithium cobalt oxide-based batteries to their limits. To obtain high voltage batteries, various methods have been adopted to lift the cutoff voltage of the batteries above 4.45 V (vs Li/Li+). This review summarizes the mechanism of capacity decay of lithium cobalt oxide during cycling. Various modifications to achieve high voltage lithium cobalt oxide, including coating and doping, are also presented. We also extend the discussion of popular modification methods for electrolytes including electrolyte additives, quasi-solid electrolytes, and electrode/electrolyte interfaces.