Engineering layer structure of MoS2/polyaniline/graphene nanocomposites to achieve fast and reversible lithium storage for high energy density aqueous lithium-ion capacitors

Abstract In recent years, many efforts are devoted to enhance the energy density of supercapacitors without sacrificing its intrinsic high power density. To achieve this, high energy density aqueous lithium-ion capacitors (LIC) are demonstrated by employing phosphorus-MoS2/polyaniline/reduced graphene oxide hierarchical nanosheets (P–MoS2/PANI/rGO HNSs) anode electrode via a simple organic/inorganic hybridization method. With the phosphorus and PANI intercalate into the adjacent MoS2 layers and then grow on the rGO nanosheets, the P–MoS2/PANI/rGO HNSs has enlarged and disordered interlayer structure and thus obtain improved Li-ion storage capability. Accordingly, an P–MoS2/PANI/rGO HNSs based LIC delivers an energy density of 56.0 Wh kg−1, when the power density is 0.45 kW kg−1. Moreover, the capacitance retention of the P–MoS2/PANI/rGO based LIC can be up to 93.5% after 30,000 charge/discharge cycles at a current density of 5 A g−1, showing great application potential for future electric vehicle.