Capacitance Performance of Nanostructured CoNi₂S₄ with Different Morphology Grown on Carbon Cloth for Supercapacitors

Abstract

Abstract Nanostructured CoNi 2 S 4 materials with different morphologies were successfully grown on carbon cloth through a facile precursor transformation method by adjusting the anions in nickel cobalt salts. The resulting samples were characterized by XRD, EDS, FESEM, and TEM and were found to display different morphologies. Their electrochemical performance was investigated by means of cyclic voltammetry (CV), galvanostatic charge–discharge, electrochemical impedance spectroscopy (EIS), and cycle life. The as‐obtained CoNi 2 S 4 sample with NO 3 − as the anion in the nickel cobalt salt displayed an ultrahigh specific capacitance of 2714 F g −1 at 1 A g −1 and excellent rate capability (64.8 % capacity retention at 20 A g −1 ). However, the as‐obtained CoNi 2 S 4 samples with SO 4 2− and Cl − as the anions in the precursors displayed a limited specific capacitance of only 1750 and 1334 F g −1 , respectively. Besides, they also displayed different performances in the cycle life test. The study indicates that the as‐obtained CoNi 2 S 4 grown on carbon cloth prepared with NO 3 − as the anion will be a promising electrode material for supercapacitors.