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