Enhancing the electrochemical performance of Ni-doped CuCo2O4 electrode material through 2D layered sheets

Abstract

In the present study, the structural and electrochemical properties on Ni-CuCo2O4 (0 <= x <= 10 %) was studied for the use of active electrode materials in asymmetric supercapacitors prepared by a simple hydrothermal process. The synthesized material's morphology shows that the nanosheets are assembled with an average diameter of about 50 nm, and the X-ray diffraction results show the spinel cubic structure with the space group of Fd-3mz (No. 227). CuCo2O4 electrodes exhibit a high specific capacitance for the electrodes because of the abundant redox reactions of Co2+/Co3+ and Co3+/Co4+, and Ni at the Co site has displayed exceptional charge-discharge and cyclic stability properties. The electrochemical studies show that the Ni doped CuCo2O4 electrode has the highest pseudocapacitive nature, with ultra-specific capacitances of 803 F g(-1), 889 F g(-1), 924 F g(-1), and 1,086 F g(-1) at 1 A g(-1) respectively for pure, 2, 6, and 10 % Ni doped CuCo2O4 electrodes. Further, the excellent rate capability with 82 % capacitance retention and 92.3 % Coulombic efficiency were realized after 1,000 cycles. Moreover, the M-H study at room temperature showed paramagnetic behaviour. Additionally, the electrochemical and magnetic characteristics of the CuCo2O4 system is expected to improve as the doping quantity of Ni increased. This study may pave the way for enhanced properties of Ni doped CuCo2O4 for futuristic hybrid devices applications.