A high energy density all-solid-state asymmetric supercapacitor based on MoS2/graphene nanosheets and MnO2/graphene hybrid electrodes

An asymmetric supercapacitor (ASC) with high energy density is designed using flower-like MoS2 and MnO2 grown on graphene nanosheets (GNS) as the negative and positive electrodes, respectively. In this paper, flower-like MoS2/GNS and MnO2/GNS electrodes were controllably synthesized through a hydrothermal approach. The prepared MoS2/GNS hybrid displays a typical crinkly and rippled structure with ultrathin MoS2 nanosheets uniformly grown on the surface of graphene. Additionally, the MoS2/GNS electrode exhibits superior electrochemical performance, such as high specific capacitance (320 F g(-1) at 2 A g(-1)). The MoS2/GNS electrode holds great promise as a negative electrode for an ASC due to its high specific capacitance and wide operation window in negative potential. The assembled all-solid-state ASC delivers a remarkable energy density of 78.9 W h kg(-1) at a power density of 284.1 W kg(-1). Thus the MoS2/GNS hybrid is a promising electrode material for next-generation storage systems.