Graphene decorated with molybdenum dioxide nanoparticles for use in high energy lithium ion capacitors with an organic electrolyte

An electrode material consisting of graphene decorated with molybdenum dioxide nanoparticles (G-MoO2) is developed. The material exhibits not only a high specific capacitance but also an excellent cycling performance as well as good rate capability in lithium ion capacitors (LICs). The specific capacitance of the G-MoO2 containing 10 wt% G reaches 624.0 F g(-1) at a current density of 50 mA g(-1), much higher than 269.2 F g(-1) for the MoO2 particles alone. Even at a current density of 1000 mA g(-1), a high specific capacitance of 173.2 F g(-1) is obtained. The capacitance retention remains 91.2% after 500 cycles. Moreover, G-MoO2 provides a high specific energy density of 33.2 W h kg(-1) at a power density of 3000 W kg(-1). The influences of the synergistic effect of nanostructured MoO2 and conducting G on the electrochemical performance of the LICs are discussed.