Biomass derived carbon as binder-free electrode materials for supercapacitors

Supercapacitors (SCs) with excellent electrochemical properties are considered as potential energy storage devices in applications of increasing power demands. Carbonaceous materials with the developed specific surface area (SSA) and abundant porous structure, are frequently combined with other carbon materials or directly used as electrode material for SCs. Renewable resources of biomass are commonly utilized as carbon precursors owing to their low-cost, easy availability, facile preparation, and environmentally friendly. This article reviews the progress in renewable resources based free-standing electrode materials on the application of supercapacitors. After a concise introduction of SCs, the methodologies on enhancement of the electrochemical performance and obtaining self-supported carbon materials are discussed. Then biomass-based binder-free electrode materials with designed unique architecture for high performance SCs are highlighted. Finally, the challenges associated with biomass derived free-standing carbon materials are pointed out and strategies to meet the practical application of supercapacitors in advanced energy storage systems are discussed. It is expected that this review would inspire researchers with new ideas to promote progress in the field.