Porous activated carbon derived from Chinese-chive for high energy hybrid lithium-ion capacitor

Lithium-ion capacitor is a hybrid electrochemical energy storage device, which combines the intercalation mechanism of lithium ion battery with the cathode of electric double-layer capacitor. To improve the energy density of hybrid Lithium-ion capacitor, a high-performance ion adsorption cathode is essential. Herein the porous activated carbon for using as cathode of hybrid Lithium-ion capacitor has been prepared through a two-step fabrication process in which naturally Chinese-chives are used as biomass carbon precursor. The biomass derived porous carbon exhibits an extremely high specific surface area (3011 m(2) g(-1)) and relatively applicable pore volume (2.6 m(3) g(-1)). Besides, it displays excellent capacitive performance with specific capacity of 124 mAh g(-1) at a current density of 0.3 A g(-1), good rate capability and outstanding cycling stability in organic electrolyte. The hybrid Lithium-ion capacitor is assembled using biomass-derived porous carbon as cathode material and the silicon/flake graphite/carbon nanocomposite as anode material. The hybrid device shows a high energy density of 159 W h kg(-1) at 945 W kg(-1) and outstanding cycle stability (with 80% capacity retention rate after 8000 cycles at 1 A g(-1)).