Utilizing bamboo shoot shells to develop hierarchical porous carbon materials for high–performance supercapacitor applications

Abstract

Hierarchical porous carbon materials were synthesized from bamboo shoot shells via KOH activation. The physicochemical properties of bamboo shoot shell–based hierarchical porous carbon (BBCK) were investigated by scanning electron microscopy, X–ray diffraction, Raman spectroscopy, X–ray photoelectron spectroscopy, and N2 adsorption–desorption analyses. Results confirmed that the ratio of KOH to BBCK significantly affected the pore structure, O content and electrochemical properties of BBCK. The obtained BBCK exhibited a specific surface area of 1394 m2 g–1 and a pore volume of 0.58 cm3 g–1. The O content of BBCK was 25.09%. The formation mechanism of BBCK, which had a hierarchical porous structure via KOH activation, was illustrated systematically. The specific capacitance was 320.05 F g–1 at 0.5 A g–1 in the 6 M KOH electrolyte, and multiplicity performance was 75.22% at 10 A g–1. The assembled symmetric supercapacitors demonstrate the power density was 250 W kg–1, and the energy density was 7.36 Wh kg–1. After 7000 cycles, the capacitance retention rate at 100%.