Simple synthesis of a CoMoS4 based nanostructure and its application for high-performance supercapacitors

Abstract

Transition metal sulfides possess multiple oxidation states that enable rich redox reactions for pseudocapacitance, which have been investigated as promising electrode materials for high-performance supercapacitors. The CoMoS₄ nanoparticles are successfully synthesized via a facile chemical co-precipitation process followed by calcining at 200 °C. The as-prepared CoMoS₄ is firstly studied systematically as an electrode material for supercapacitors. Benefiting from the improved electron conductivity, low crystallinity, and effective porous structure, the as-fabricated CoMoS₄ exhibits a high specific capacitance of 415 F g⁻¹ at a current density of 0.5 A g⁻¹, a superior rate capability of 82.1% retention as the current density increased from 0.5 A g⁻¹ to 5 A g⁻¹, and an excellent cycling stability of 100% retention after 10 000 cycles at a current density of 2 A g⁻¹ in 6 M KOH aqueous electrolyte. Interestingly, the as-prepared CoMoS₄ achieves much more outstanding capacitive properties than those of CoS and MoS₂, which indicates a synergistic effect of the double metal sulfides on improvement of the electrochemical performance. The findings demonstrate the importance and great potential of CoMoS₄ nanoparticles in the development of high-performance energy-storage systems.