Facile microwave-assisted synthesis of cobalt diselenide/reduced graphene oxide composite for high-performance supercapacitors

The composites composed of metal selenides and carbonaceous materials have revealed enormous potential in varied applications. Herein, CoSe2/reduced graphene oxide (CoSe2/RGO) composites are prepared by a low-cost and efficient microwave assisted method. The effects of RGO proportion on crystalline structure, microstructure and energy storage capacity are explored. Benefiting from the good electrical conductivity and reasonable RGO content, the CoSe2/RGO sample with 35.2 wt% RGO reveals an excellent specific capacitance of 761 F g(-1) as well as outstanding durability. More importantly, we construct an all solid-state hybrid supercapacitor (CoSe2/RGO// active carbon) to broaden the voltage window, resulting in an enhanced energy density (43.1 Wh kg(-1)). The hybrid device presents a favorable durability with 10% capacity drop after 10,000 cycles. In addition, the practical applicability of asymmetric device is confirmed by powering a blue light emitting diode (LED) for more than 10 mins. This work presents a simple, effective, and reasonable construct strategy to synthesize composites of selenides and RGO for charge storage application.

Automated summary

The study shows that CoSe2/RGO composites exhibit excellent specific capacitance and durability, with the best performance achieved at 35.2 wt% RGO content. The hybrid supercapacitor using solid-state materials broadens the voltage window and enhances energy density.