Scale-up biomass strategy to macro-microporous nitrogen-doped carbon aerogels for ionic liquid supercapacitors with high efficiency

Ionic liquids are commonly employed as supercapacitor electrolytes owing to their wide voltage windows. However, ion transport in a carbon electrode is limited by the larger viscosity and larger ion size of an ionic liquid, which reduces the energy density of supercapacitors. In this work, we fabricated macro-microporous nitrogen-doped carbon aerogels (H-A-C-N) as electrode materials by scale-up biomass strategy for high-energy-density supercapacitors. The macroporous structure ensures the rapid transport of ions in the ionic liquid, particularly under high-current charging and discharging conditions. We fabricated a symmetric supercapacitor using the H-A-C-N as the electrode and 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim]BF₄) as the electrolyte. The developed supercapacitor presents an energy density of 68.8 Wh kg⁻¹. The results of this study present considerable potential for the preparation of high-performance electrode materials in future studies.