Electrochemical performance of asymmetric supercapacitors based on NiCo(OH)4/Cu2(OH)3NO3 electrode

Copper salt metal compounds are widely used in the field of supercapacitor electrode material due to their rich ionic groups. In this paper, NiCo(OH) 4 /Cu 2 (OH) 3 NO 3 electrode material is prepared by the solvothermal method by doping NiCo-based hydroxide with copper salt metal compounds (Cu 2 (OH) 3 NO 3 ). NiCo(OH) 4 /Cu 2 (OH) 3 NO 3 electrode material with different morphologies and sizes is prepared by adjusting the concentration of metal salts. When the metal salt concentration is 2 M, the prepared circular sheet NiCo(OH) 4 /Cu 2 (OH) 3 NO 3 electrode material with a diameter of 3 μm and a thickness of 150 nm exhibits excellent specific capacitance (1335 C g −1 at 1 A g −1 ) and capacitance retention (after 5000 cycles, the capacitance retention rate is 71.7 %). Furthermore, the NiCo(OH) 4 /Cu 2 (OH) 3 NO 3 //AC asymmetric supercapacitor is prepared, which exhibited an energy density is 83.78 Wh kg −1 at a power density of 800 W kg −1 . The capacitance retention rate of the asymmetric supercapacitor is 65.2 % (after 5000 cycles at 10 A g −1 ). We used copper salt metal compounds (Cu 2 (OH) 3 NO 3 ) to improve the electrochemical performance of NiCo-based hydroxide electrode material. This idea has certain reference significance for improving the performance of NiCo-based hydroxide electrode material.