Ammonium nickel‐cobalt phosphate nanoflowers on highly conductive carbon fibers as an electrode material for enhanced electrochemical performance supercapacitors

The nickel cobalt ammonium phosphate (NH4(Ni, Co)PO4)/carbon fibers (CFs) electrode materials were prepared by a hydrothermal method. The nanoflower-like active materials (NH4(Ni, Co)PO4) have an average particle size of about 500 nm, which are uniformly and tightly dispersed on the surface of CFs. The specific capacitance of the composite electrode NCCF-3 with a molar ratio of Co and Ni of 1:1 is as high as 811.1 F·g−1 at the current density of 1.25 A·g−1. Meanwhile, the electrochemical performance of NCCF-3 exhibits a good reversibility and batter stability of 89.1% capacitance retention after 2000 cycles. The maximum energy density of NCCF-3 is 20.28 Wh·kg−1 at the power density of 189.17 W·kg−1. The electric double-layer of the high-conductivity CFs combined with the pseudocapacitance of NH4(Ni, Co)PO4 will help to improve their electrochemical performances. The NCCF-3 electrode materials, which can effectively improve the capacitance and stability, are a potential composite electrode for the applications of a supercapacitor.