Unlocking the potential of cellulose-based composite materials for supercapacitors and sensing technologies: A Review

Abstract

Cellulose aerogels exhibit a specific surface area (10–975 m² g⁻¹), porosity (84.0–99.9 %), and density (0.0005–0.35 g cm-³) comparable to synthetic polymer aerogels, but uniquely offer higher compressive strength (5.2 kPa–16.67 MPa) alongside superior biodegradability. Cellulose-based aerogels have experienced significant growth in research interest over the past decade. Publications in this field have dramatically increased from 19 in 2010 to over 385 in 2024, highlighting their unique physicochemical characteristics. Renowned for their porous structure, low thermal conductivity, low density, and exceptional adsorption capabilities for water and organic solvents, cellulose aerogels hold substantial promise for high-performance materials. This review, therefore, aims to illustrate three key aerogel processing routes: dispersion, regeneration, and cellulose derivative methods, alongside five prominent modification techniques for aerogel composites. Furthermore, it briefly discusses the application of cellulose aerogels as a core component in supercapacitors (electrodes, separators, and electrolytes), showcasing examples like fluorine-treated CNF achieving 409 F g⁻¹ specific capacitance with 91 % retention after 10,000 cycles. The review also examines the utilization of these aerogels in electrochemical, pressure, piezoelectric, humidity, and environmental sensors, concluding with a discussion of their potential future implications and applications.