Interfacial Polymetallic Oxides and Hierarchical Porous Core–Shell Fibres for High Energy‐Density Electrochemical Supercapacitors

摘要

Abstract Realizing high energy‐density and actual applications of fibre‐based electrochemical supercapacitors (FESCs) are pivotal but challenging, as the ability to construct advanced fibres for accelerating charges kinetic diffusion and Faradaic storage remain key bottlenecks. Here, we demonstrate high‐performance FESCs based on hetero‐structured polymetallic oxides/porous graphene core–sheath fibres, where the large pseudo‐active polymetallic oxide (PMO) sheath is uniformly loaded on a hierarchical porous graphene fibre (PGF) core. Due to the abundant micro‐/mesoporous pathways, large accessible surface, excellent redox activity and good interface electron conduction, the PMO‐PGF possesses high areal capacitance (2959.78?mF?cm?2) and manageable Faradaic reversibility in a 6?M KOH electrolyte. Furthermore, the PMO‐PGF‐based solid‐state FESCs present high energy‐density (187.22?μ?Wh?cm?2), long‐life cycles (95.8?% capacitive retention after 20?000?cycles), diverse‐powered capabilities and actual energy‐supply applications.