Tailoring pore structures in hierarchical activated carbon from bamboo steam treatment for high performance supercapacitors

Recently, hierarchical porous carbons material from biomass have attracted much research due to their exclusive properties and have been applied broadly in energy storage systems. However, the optimal on pore volume and the ratio of micro/meso/macro pores of carbon material for electrodes in electric double-layer capacitors (EDLC) are still challenging. In this study, a facile method to synthesize a unique hierarchical porous carbon material with optimal pore structure was developed for EDLC. The optimal sample, which prepared at the weight ratio of 1:1.5:1 (bamboo steam treatment: K2C2O4: CaCO3), exhibited the high specific capacitance value of 213 F g−1 at 1 A g−1 in 6 M KOH aqueous electrolyte. Furthermore, the capacitance value of the sample in three electrodes revealed an excellent cycling stability of 102 % and Coulombic efficiency of 100 % after 60,000 cycles. The fabricated symmetric electrode in 1 M TEABF4/PC organic electrolyte delivered a remarkable energy density of 13.8 W h kg−1 at a power density of 1265 W kg−1 and could remain 12.7 W h kg −1 at the notable value of 30,274 W kg−1. This method has comprehensive worth in producing hierarchical activated carbon via sustainable and friendly environment process for energy storage applications.