The role of feedstock and activation process on supercapacitor performance of lignocellulosic biochar

Porous carbons derived from lignocellulosic biomass and their use in electrochemical applications are attracting a growing level of interest due to the sustainable nature of the materials and its favourable properties. This study investigates the influence of feedstocks and three activation methods (CO2, steam, and KOH) on the electrochemical properties of lignocellulosic biochars. The results showed that activated biochars derived from straw biomass had a higher specific capacitance than wood-derived activated biochars, despite lower electrical conductivity and porosity. Furthermore, chemical activation using KOH was found to increase the capacitance of activated biochars compared to physical activation using steam and CO2, although sometimes at the expense of electrical conductivity. The study highlights the importance of carefully selecting the feedstocks and activation methods to optimise the electrochemical properties of biochar for potential use as a sustainable supercapacitor material.