Recent advances and challenges in biomass-derived carbon materials for supercapacitors: A review

Carbon materials with large specific surface areas, high durability, and unique internal structure have made them as a research hotspot in energy storage. Biomass, the only renewable carbon source, is abundant, cost effective and high in carbon content, which have been familiarly used in the production of high-performance carbon materials on an industrial scale. Many studies have shown that biomass-derived carbon materials (bio-carbons) have received increasing attention for their greater ability in mitigating environmental problems and promoting sustainable energy storage applications. The present review has overviewed the current progress in the application of bio-carbons as electrodes for supercapacitors. Biomass source and preparation process of bio-carbons were significantly expounded. The influence of heteroatom doping, specific surface area, and pore structure on bio-carbons' electrochemical properties (e.g., specific capacitance, cycle life) have been discussed. Finally, the promising future developments, needed directions and present challenges of bio-carbons in the field of supercapacitors are summarized, providing helpful inspiration for the future development and for efficient utilization of bio-carbons.