“Thermal dissolution carbon enrichment” treatment of biomass wastes: Supercapacitor electrode preparation using the residue

“Thermal dissolution carbon enrichment” method proposed in our previous work has been proved to effectively separate biomass wastes into carbon-rich target products (the extracts) and a byproduct (the residue). In consideration of its improved gasification reactivity and concentrated minerals, the residue possesses great potential for high performance activated carbon preparation and further application for the supercapacitor. Therefore, in this study, the residue was firstly activated into porous carbon, and then utilized as supercapacitor electrode. Meanwhile, the activated carbons prepared from raw biomass with or without thermal pretreatment were also produced for comparison purpose. Results showed that the activated carbon prepared from residue has highest specific surface area of 2764 m2/g with hierarchical structure, and its derived supercapacitor possessed good capacitive performance including a specific capacitance of 228 F/g and low charge transfer resistance as well as diffusional resistance. Hence, the possibility of utilizing residue for supercapacitor was proved, and the practical application of “thermal dissolution carbon enrichment” method enters a new stage.