Sustainable biomass-derived carbon aerogels for energy storage applications

Carbon aerogels are widely used in supercapacitors, secondary batteries, electrocatalysis and even sensors, due to their low density, high porosity, large specific surface area, mechanical stability, and high conductivity. Nevertheless, the precursors of inorganic carbon aerogels are derived from non-renewable sources, posing challenges such as costly and intricate preparation methods with limited yields. In contrast, biomass presents favorable attributes, being abundant in natural resources, renewable, environmentally friendly, and costeffective. Consequently, the development of biomass-based carbon aerogels with controllable microstructure/ surface functionalization, renewable precursors, environmentally friendly, low cost, high specific surface area, electrical conductivity, and good chemical stability holds promising prospects in the field of energy storage. Over the past five years, numerous studies have focused on converting various waste biomasses into valuable carbon aerogels with applications across diverse research areas. This review summarizes recent advances in biomassbased functional carbon aerogels for energy storage, providing insights into their emerging applications in various fields. The review comprehensively covers recent progress in energy-oriented applications, such as supercapacitors, hybrid capacitors, metal-ion batteries, and fuel cells, highlighting the significant strides made in these areas. Finally, the paper discusses and outlines the main challenges and opportunities that biomass-based functionalized carbon aerogels still face in the future.