Spherical-Like Ball-by-Ball Architecture of Ni-Co-Zn-S Electrodes for Electrochemical Energy Storage Application in Supercapacitors

Abstract

Spherical-like ball-by-ball architecture of Ni-Co-Zn-S was obtained through one pot simple and facile hydrothermal method without any surfactant. The as synthesized crystalline powder was characterized by using various tools like powder X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Furthermore, the electrochemical performance studies were carried out from cyclic-voltammetry (CV), galvanostatic charge–discharge (CD) and electrochemical impedance spectroscopy (EIS), within 3.5 M KOH. The consistent increment of clear redox peaks were obtained from CV characteristics due to synergic activities of Ni, Co and Zn. In addition, the presence of Zn ions into Ni and Co has increased its electronic conductivity; therefore, we could observe the superior performance. Thus, Ni-Co-Zn-S exhibited a maximum specific capacitance of 825, 680, 582, 512, 460, 432, 392 and 328 Fg−1 at 1, 2, 3, 4, 5, 6, 7 and 10 Ag−1 within 3.5 M KOH electrolyte. The obtained results are suggesting the excellent electrochemical activities with affordable rate of Ni-Co-Zn-S which is suitable electrode for device applications. Thus, our results may pave the way for the fabrication of advanced high energy storage device through a low-cost preparation to attain the extraordinary limit in energy device industry.