Pitaya peel derived carbons with ultra-high specific surface area for solid-state flexible asymmetric supercapacitors

Abstract

In this paper, a well-designed process to fabricate bio-mass carbon with ultra-high specific surface area (UHSSA) and hierarchical porous (HP) structure is achieved. The process pre-treating with ethanol and KOH cooperatively is first introduced to optimize the microstructure and porosity. The as-prepared carbons present an UHSSA of ca. 3521 m2 [Formula: see text] g[Formula: see text], with large amounts of micro and mesopores. The assembled asymmetric flexible super-capacitor (SC) holds very high energy density of 49.9 Wh [Formula: see text] kg[Formula: see text] at 90 W [Formula: see text] kg[Formula: see text], and 10.3 Wh [Formula: see text] kg[Formula: see text] at the higher power density of 9 kW [Formula: see text] kg[Formula: see text], demonstrating that the device possesses long cyclic life and well stability. The exciting results reveal that our study provides an effective approach to biomass recycling by pre-treatment of ethanol and KOH producing HP carbons possessing ultra-high SSA for high-energy storage applications.