Recent advances of cathode materials for zinc-ion hybrid capacitors

Zinc-ion hybrid capacitors (ZIHCs) have attracted increasing attention in recent years due to their merits such as environmental benignity, cost effectiveness, highly intrinsic safety, ease of assembling in air. ZIHCs composed of capacitor-type electrode and battery-type electrode are regarded as the combination of high power density and long cycling lifespan of supercapacitors and high energy density of zinc-ion battery. However, the electrochemical performance of ZIHCs is still far from the practical application. Here, this review comprehensively summarizes recent advances towards the capacitor-type and battery-type cathodes of ZIHCs and mechanism understanding of cathodes with a focus on carbon-based cathode materials. Moreover, we summarize the equations for performance parameter calculation for unify. Besides, the applications of ZIHCs towards integration and multi-functionality are briefly showcased. Pertinent insights into the development of cathode materials for ZIHCs are presented for constructing high-performance ZIHCs to realize their large-scale development.