Co3O4 nanowire@ultrathin Ni-Co layered double hydroxide core-shell arrays with vertical transfer channel for high-performance supercapacitor

Abstract

High electrochemical performance of supercapacitor electrodes largely rely on the heterostructure of different active component materials. Furthermore, the integration of Co3O4 nanowire (internal conductive highway) to bridge the Ni-Co layered double hydroxides nanosheets (provided high specific capacity), which is favorable for fast charge transfer, as well as improved conductivity. Thus, the Co3O4@Ni-Co LDH core-shell nanowire arrays electrodes exhibit a remarkable specific capacitance (1318 F·g−1 at 0.5 A·g−1) and also a relatively low resistance. Due to synergistic interaction of porous NiCo-LDH nanosheets and inner Co3O4 nanowire, an asymmetric supercapacitor (ASC) is assembled with Co3O4@Ni-Co LDH as the anode and active carbon as cathode. The as-fabricated ASC shows high energy density of 46.3 Wh·kg−1 and exhibit superior cyclic stability of 92% retention after 5000 cycles, suggesting this electrode is promising for efficient electrochemical capacitors.