Research progress of metal oxides as anode materials for lithium ion capacitors

As a new type of energy storage device, lithium-ion capacitor (LIC) combines the advantages of both supercapacitors and lithium-ion batteries, which can provide high energy density, high power density and stable cyclic life. LICs are considered a promising candidate for energy storage in the fields of electric vehicles, rail transit, smart grids, and mobile electronic devices, ushering in their great prospects. Due to the high theoretical specific capacity, naturally abundance and environmental friendliness, metal oxides are considered as ideal anode materials for LICs. However, the low electronic conductivity and huge irreversible volumetric distortion greatly restrict their potential application. In this review, the preparation methods of metal oxide anode materials are summarized, and their electrochemical performances, advantages and disadvantages for LICs are analyzed. Finally, the future development of metal oxide anode materials is also discussed.