A General Eco-friendly Production of Bio-sources Derived Micro-/Mesoporous Carbons with Robust Supercapacitive Behaviors and Sodium-Ion Storage

Recently, biomass-derived carbons (BDCs) have attracted great attention as energy storage materials due to their congenital advantages. However, green and moderate activation protocols for advanced BDCs are still challengeable. Herein, we devised a scalable, yet general, strategy to fabricate a series of porous BDCs via direct activation of various abundant biomass resources by using KHCO3 as eco-friendly activator. The BDCs activated by KHCO3 exhibited even better electrochemical behaviors than other activators. More encouragingly, the optimized shiitake mushroom derived carbon (C-KHCO3) was endowed with a surface area of 1788.1 m(2) g(-1), average pore size of 2.5 nm, high-content N (1.3 at. %), and mass density of 0.62 g cm(-3). When evaluated as electrodes for supercapacitors, our fabricated electrode (5 mg cm(-2)) in a three-electrode configuration exhibited competitive capacitance of 354.8 F g(-1) (220.0 F cm(-3)) at a rate of 1.0 A g(-1) in 1 M H2SO4. Furthermore, the organic C-KHCO3//C-KHCO3 symmetric capacitor delivered an energy density of 55.2 Wh kg(-1) (34.2 Wh L-1) at 1250 W kg(-1), and long-duration cycling performance. Moreover, the resultant C-KHCO3 was also highlighted with remarkable Na+-storage behaviors. Promisingly, the methodology here shows attractive superiorities in cost efficiency, good universality and scalability to commercial levels of BDCs for energy-related applications.