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

Abstract

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.