A hybrid NiCo2O4@NiMoO4 structure for overall water splitting and excellent hybrid energy storage

Abstract

In this study, a two-step hydrothermal method is used to prepare NiCo₂O₄@NiMoO₄ nanoscale materials for periodic stability supercapacitors. The synthesized product can be directly used as the electrode material of the supercapacitor, and its specific capacitance is 685.7 C g⁻¹. The composite electrode NiCo₂O₄@NiMoO₄ is used as the positive electrode and the hybrid capacitor is assembled. Meanwhile, at the power density of 4050 W kg⁻¹, the energy density is 96.3 W h kg⁻¹, and the capacitance retention is 100% after 10 000 cycles. At the same time, when the composite is used as a catalyst, it exhibits OER overvoltage (300 mV), HER overvoltage (170 mV) and a low battery voltage of 1.65 V at 10 mA cm⁻². After 14 hours of long-term use, NiCo₂O₄@NiMoO₄ maintained good stability, indicating that its structure further improved the electrochemical performance, providing a great advantage for the study of low-cost electrode materials for overall water splitting.