LAUSR

Abstract The intertwined fiber structure is advantageous as a structure of supercapacitor electrode material. In this paper, the NiCo2S4 embedded in carbon fiber (NiCo2S4/CF) has been prepared through hydrothermal vulcanization of electrospun NiCo2O4/carbon nanofibers precursor. It is a simple way to integrate the pseudocapacitive material with carbon, rendering high capacitance (1169 F g−1 at 1 A g−1), excellent rate capability (81.3% at 20 A g−1) and superior cycle stability (87.2% capacitance retention after 10,000 cycles). Afterwards, an all-solid-state asymmetric supercapacitor device (ASC) has been prepared with the NiCo2S4/CF positive electrode and porous carbon nanofiber negative electrode. When the power density of ASC is 878.3 W kg−1, the energy density can reach 28.8 Wh kg−1 with excellent cycle stability.