3D porous Li3VO4@C composite anodes with ultra-high rate capacity for lithium-ion capacitors

Abstract

Lithium ion capacitors have attracted enormous interest in recent years due to their high energy density, high power density as well as long cycle stability. However, it remains as a grand challenge to find a suitable battery-type anode material with low Li-ion insertion potential and fast electrochemical kinetics. In this work, we demonstrate that the 3D porous Li3VO4@C composites synthesized by a facile freeze-drying-assisted thermal treatment method can be favorably used for high-performance lithium ion capacitors. Benefiting from the uniformly distributed Li3VO4 nanoparticles and interconnected conductive carbon networks, the 3D porous Li3VO4@C anode displays a fast kinetics for both charge-transfer and ion-diffusion, excellent rate capability (317 mAh/g even at a high rate of 10 A/g) and superior cycling stability (322 mAh/g at 5A/g after 2000 cycles). A lithium ion capacitor based on these 3D porous Li3VO4@C composites delivers high energy/power densities (129.7 Wh/kg at 251.8 W/kg, 52.8 Wh/kg even at 15.2 kW/kg), revealing the promising potential applications in high-performance and long life Lithium ion capacitors.