Pore-tailoring of pruned fruit tree branch derived activated carbon with hierarchical micropore structure for non-aqueous supercapacitors

Abstract

In non-aqueous supercapacitors, pore-tailoring of electrode materials is important for organic ion storage and accessibility. Herein, we report a pruned fruit tree branch derived activated carbon that has a hierarchical micropore structure suitable for non-aqueous supercapacitors. Pruned peach and apple tree branches are used as the biomass base in which two different pore-tailoring strategies are performed through an alkali activation and a self-template using naturally occurring compounds in the biomass. In tailoring, the amount of KOH was regulated to increase the specific surface area and pore volume, for the creation of energy storage related pores. Furthermore, CaCO3 particles (<2 nm) in carbonized pruned fruit tree branches were additionally contribute to create interconnecting micropores. The obtained activated carbons show suitable futures for electrochemical performance such as high surface area (up to 3090 m2 g−1) and pore volume (up to 1.39 cm3 g−1). The largest specific capacitance of 167.0 F g−1 was obtained when the pruned apple tree branch based electrode was used with an organic electrolyte. The maximum energy and power densities achieved were 42.1 Wh kg−1 and 7.1 kW kg−1, respectively. The results of this study present an environment friendly method to control the porosity in biomass-derived activated carbon for sustainable energy storage applications.