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 Ni2CoS4/graphene oxide (MH-Ni2CoS4/GO). Firstly, Ni2CoS4 nanoparticles are observed to grow uniformly on the surface of GO. Then the obtained MH-Ni2CoS4/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-Ni2CoS4/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. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

A simple and efficient strategy was used to synthesize Ni2CoS4/graphene oxide through the synergistic effect of microwave heating method and hydrothermal method. The resulting electrode demonstrated ultrahigh specific capacitance, excellent stability, and outstanding rate capability in supercapacitors, as well as delivering a good specific capacitance, outstanding stability, and ultrahigh energy density in asymmetric supercapacitors. This work provides a method for synthesizing electrode materials with superior performances in practical applications in supercapacitors.