Preparation of hierarchical porous carbon materials from bamboo shoot shells via air activation for high–performance supercapacitors
Fanen Zeng, Yaning Zhang, Qi Lv, Lu Lu, Bing Xu
Abstract
Hierarchical porous carbon materials were synthesized from bamboo shoot shells through carbonization and static air activation. The physicochemical properties of bamboo shoot shell–based porous carbon (BBC) were observed by scanning electron microscopy with energy dispersive X–ray spectroscopy, X–ray diffraction, Raman spectroscopy, X–ray photoelectron spectroscopy, and N2 adsorption–desorption analysis. The BBC activated at 800 ℃ has a developed hierarchical porous structure that displays a specific surface area of 546.04 m2 g–1 and an average pore diameter of 3.28 nm. The formation mechanism of the BBC, which has a hierarchical porous structure in static air activation, was illustrated systematically. Within the three–electrode system, the BBC activated at 800 ℃ exhibits a specific capacitance of 172.65 F g–1 at a current density of 0.5 A g–1 and an excellent rate capability of 85.46 % at a current density of 5 A g–1. To evaluate the suitability of BBC for practical implementations further, the constructed symmetric SC with the best BBC as electrode material, when the power density is 252 W kg–1, the energy density is 11.11 Wh kg–1 and an outstanding cyclic retention rate of 100 % over 7000 cycles at a current density of 10 A g–1.