NiCoP/Co9S8 nanoflowers as advanced electrode material for asymmetric supercapacitors

This work presents the synthesis of NiCoP using the Kirkendall effect and the preparation of a three-dimensional (3D) nanoflower-like structure of NiCoP/Co9S8 through sulfur-induced dissociation. The optimized electrode sample exhibited a capacity of 1252 μAh cm−2 (31.3 mAh g−1) at 1 mA cm−2 and 898 μAh cm−2 (22.5 mAh g−1) at 30 mA cm−2. The assembled NiCoP/Co9S8 electrode/active carbon (AC)-based asymmetric supercapacitor (ASC) demonstrated a capacity retention rate of 87 % after 5000 cycles at 20 mA cm−2 current density. Furthermore, the optimized NiCoP/Co9S8 composite showed a power density of 480.1 W kg−1 at an energy density of 115.1 Wh kg−1 and a power density of 4800.1 Wh kg−1 at an energy density of 66.4 W kg−1. These findings highlight the potential of the 3D NiCoP/Co9S8 nanoflower-like structure for application in asymmetric supercapacitors.