Boron and nitrogen dual-doped carbon as a novel cathode for high performance hybrid ion capacitors

Abstract

Hybrid ion capacitors have been considered as a very attractive energy source with high energy density and power density since it combines both merits of lithium ion batteries and supercapacitors. However, their commercial application has been limited by the mismatch of charge-storage capacity and electrode kinetics between the capacitor-type cathode and battery-type anode. Herein, B and N dual-doped 3D superstructure carbon cathode is prepared through a facile template method. It delivers a high specific capacity, excellent rate capability and good cycling stability due to the B, N dual-doping, which has a profound effect in control the porosity, functional groups, and electronic conductivity for the carbon cathode. The hybrid ion capacitors using B, N dual-doping carbon cathode and prelithiated graphite anode show a high energy density of 115.5Wh/kg at 250W/kg and remain about 53.6Wh/kg even at a high power density of 10kW/kg. Additionally, the novel hybrid device achieves 76.3% capacity retention after 2000 cycles tested at 1250W/kg power density. Significantly, the simultaneous manipulation of heteroatoms in carbon materials provides new opportunities to boost the energy and power density for hybrid ion capacitors.