Self-supporting composite electrode modified with Ni3S2nanosheets: For high performance supercapacitors

The microstructural optimization for electrode materials is a critical approach to enhance the electrochemical performance of supercapacitors. This paper used pine wood as a precursor and prepared a self-supporting carbon electrode (CW) with developed porous structure through high-temperature carbonization. CW can be directly used as an electrode for supercapacitors without the need for binders or conductive agents. Subsequently, Ni3S2nanosheets were uniformly deposited on the surface and channel walls of CW by electrodeposition method, the self-supporting composite electrode composite electrode modified with Ni3S2nanosheets (CW@Ni3S2–20) was prepared. CW@Ni3S2–20 demonstrated excellent electrochemical performance, achieving a high specific capacitance of 3.075 F cm−2at a current density of 5 mA cm−2. In addition, a hybrid supercapacitor CW@Ni3S2–20//HCW-0.7 was assembled using CW@Ni3S2–20 as the cathode. The hybrid supercapacitor exhibited a high energy density and excellent cyclic stability, at a current density of 4 mW cm−2, the energy density reached 0.42 mWh cm−2, and the capacity retention rate remained at 88.07 % after undergoing 5000 charge-discharge cycles under the current density of 100 mA cm−2.