Synergistic effect of microwave heating and hydrothermal methods on synthesized Ni2CoS4/GO for ultrahigh capacity supercapacitors.

A simple and efficient strategy that takes advantages of the synergistic effect of microwave heating method and hydrothermal method is used to synthesize Ni 2 CoS 4 /graphene oxide (MH-Ni 2 CoS 4 /GO). Firstly, Ni 2 CoS 4 nanoparticles are observed to grow uniformly on the surface of GO. Then the obtained MH-Ni 2 CoS 4 /GO electrode is tested and it demonstrates ultrahigh specific capacitance of 2675.0 F g−1 at the current densities of 2 A g−1, fantastic stability of 95.0% even after 2000 cycles at 30 A g−1 and excellent rate capability of 89.7% with current density increasing from 2 A g−1 to 30 A g−1. Moreover, the assembled AC//MH-Ni 2 CoS 4 /GO asymmetric supercapacitor also delivers a good specific capacitance of 126.5 F g−1 at 0.5 A g−1, outstanding stability of 97.0% after 2000 cycles at 5.0 A g−1, and an ultrahigh energy density of 59.6 Wh kg−1 at power density of 497.6 W kg−1. This work provides an approach to synthesize electrode materials with superior excellent performances and it can be easily scaled up for practical applications in supercapacitors. [ABSTRACT FROM AUTHOR]