In situ growth of burl-like nickel cobalt sulfide on carbon fibers as high-performance supercapacitors

Abstract

Nickel cobalt sulfide (NiCo₂S₄), a recently reported novel electrode material, has a higher electric conductivity than that of NiCo₂O₄. We describe a facile one-step route to the development of burl-like NiCo₂S₄ on carbon fiber paper/cloth (CFP/CFC) used as electrodes for supercapacitors. The influence of the carbon substrate on the crystal structure and electrochemical performance of the NiCo₂S₄ electrodes is evaluated. We obtained a pure phase of NiCo₂S₄ over a CFP substrate, whereas, a mixed phase over a CFC substrate. Superior pseudocapacitive performance is achieved over NiCo₂S₄/CFP with a large specific capacitance of 0.83 F cm⁻² at a high current density of 25 mA cm⁻². The capacitance loss is 24.1% after 5000 cycles at a current density of 20 mA cm⁻², displaying good cyclability and high rate capability.