Waste biomass-based 3D graphene aerogels for high performance zinc-ion hybrid supercapacitors

Biomass-based 3D graphene aerogels were explored as cathode materials for the fabrication of high-performance zinc-ion hybrid supercapacitors. These hybrid supercapacitors delivered a high specific capacitance of ∼353.1 F g^-1 at a current density of 0.1 A g^-1 and maximum specific energy and power of 158.9 W h kg^-1 (at 84 W kg^-1 of specific power) and 14.8 kW kg^-1 (at 77.2 W h kg^-1 of specific energy), respectively. These devices exhibited a remarkable rate capability at high current densities and excellent capacity retention, retaining ∼84.2% of their capacity with ∼100% coulombic efficiency up to 10 000 cycles at 10 A g^-1.