A review of carbon-based cathode materials for zinc-ion capacitors

Zinc-ion capacitors are high-performance hybrid capacitors that have great advantages because of the abundance of zinc resources and their high theoretical capacitance. As a result they have become a hot research topic in the field of energy storage devices. Carbon-based materials are usually used as the cathode materials for these capacitors because of the wide range of available materials, and their easily tuned surface properties and simple fabrication. This review summarizes recent research progress on carbon cathode materials for flexible/non-flexible zinc ion capacitors, and gives a concise description of their novel structures and outstanding performance. It then discusses research on the energy storage mechanisms in the cathode materials and suggests directions for the development of carbon cathodes for zinc-ion capacitors.