Carbon nanomaterials for aqueous zinc-ion capacitors:recent progress,challenges,and perspectives

Zinc-ion hybrid capacitors(ZHCs),integrating the high power density of supercapacitors and high energy density of batteries,are an emerging and sustainable electrochemical energy storage device.However,the poor rate performance,low utilization of active sites and unsatisfactory cycling life of capacitive-type cathode are still current technical challenges,while the uneven deposition of zinc anode generates a large number of dendrites,which can easily penetrate the separator to cause device failure,greatly limiting the commercialization prospects of ZHCs.Here,this review systematically elaborates on the current research progress of cathode materials for ZHCs,including preparation methods and structural design of porous carbon and heteroatom-doped porous carbon,deeply analyzing and discussing the energy storage mechanism and electrochemical behavior.Moreover,this review analyzes the causes and inhibition mechanisms of zinc dendrites,including electrolyte modification,induced uniform deposition of zinc and zinc anode modification,systematically elaborating on the three directions of current modification strategies for zinc anode.Finally,the current challenges and future development of cathode materials and dendrite suppression were prospected,developing a high-performance ZHCs.