Amorphous CoMoS4 for a valuable energy storage material candidate

•The prepared amorphous CoMoS4 was firstly used in supercapacitors.•The specific capacitance of CoMoS4 can reach 661 F g−1 at 1 A g−1.•The assembled CoMoS4//rGO hybrid supercapacitor own good supercapacitive behaviors.

The amorphous CoMoS4 is prepared using a simple precipitation method and for the first time used as a supercapacitor material. Surprisingly, it possesses very good electrochemical behavior owing to its amorphous structure and multiple oxidation states. In a three-electrode system, the ratio capacitance of CoMoS4 sample can reach 661 F g−1 at a current density of 1 A g−1. In the actual application of CoMoS4, the CoMoS4 symmetric device shows the ratio capacitance of 142 F g−1 at 2 A g−1; the assembled CoMoS4//rGO hybrid supercapacitor also owns a high ratio capacitance of 68 F g−1 at 1 A g−1 with energy and power densities of 27.2 Wh kg−1 at 400 W kg−1 and 17 Wh kg−1 at 2400 W kg−1. Further the hybrid supercapacitor has good capacitance retention (86% after 10,000 cycles), low internal and Warburg resistances.