Incorporation of CeO2 Nanosheets into MnCoSx Hollow Nanorods for Next Generation Supercapacitors

Abstract

Cerium oxide facilitates redox reactions due to the presence of a reversible redox couple, but its conductivity is not high. The presence of manganese–cobalt sulfide (MnCoS) as a transition metal sulfide, along with cerium oxide, boosts the electrical conductivity and electrochemical properties. Herein, MnCoS hollow nanorods were synthesized on cerium oxide nanosheets (MnCoS/CeO₂) using a hydrothermal technique. The specific capacitance is 772.5 F g^–1 at 1 A g^–1 for MnCoS/CeO₂. It also demonstrated high cyclic stability, maintaining an 89% capacitance after 2500 cycles. Additionally, a battery-type asymmetric supercapacitor (MnCoS/CeO₂//activated carbon) was constructed with an energy density of 24.9 Wh kg^–1 at 407.6 W kg^–1. The device capacitance is retained at 75% after 5000 cycles, showing good cyclic stability. These findings suggest that the MnCoS/CeO₂ composite offers significant potential for enhancing supercapacitor performance and energy storage devices in general.