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

Abstract

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/Cu2(OH)3NO3 electrode material is prepared by the solvothermal method by doping NiCo-based hydroxide with copper salt metal compounds (Cu2(OH)3NO3). NiCo(OH)4/Cu2(OH)3NO3 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/Cu2(OH)3NO3 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/Cu2(OH)3NO3//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 (Cu2(OH)3NO3) 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.