High-performance MoSe2/rGO composites based on interface and phase engineering for all-solid-state symmetric supercapacitors

The energy storage capacity of supercapacitors depends on the electrode structure of the active material and its properties related to capacitance. Improving the properties of active materials through engineering strategies is essential to obtain high-energy supercapacitors. Here, we combine interface and phase engineering to overcome the inherent limitations of MoSe2 and improve their charge storage capacity. MoSe2 was anchored to reduced graphene oxide (rGO) using a simple hydrothermal method to form a heterogeneous structure. This approach provided a large number of electrode/electrolyte contact interfaces. The synergistic interaction of MoSe2 and rGO also enhances the overall electrical conductivity and structural stability. At the same time, the phase conversion of the MoSe2 material is triggered by the intercalation of Na+ ions to increasethe layer spacing and, thus, the charge storage capacity. In summary, MoSe2/rGO were prepared by engineering strategies with a high specific capacitance of 169.3 F g−1 at 0.5 A g−1. The assembled all-solid-state symmetrical supercapacitor (ASSC) devices have good cycling stability (83.1 % over 10,000 cycles) and potential practical applicability.