Cellulose Nanocrystals in Sustainable Energy Systems

The transition to low-carbon emitting technologies provokes an increasing demand in energy conversion and storage systems such as fuel cells, batteries, and supercapacitors, and consequently, the need for their raw materials. The use of new chemistries from earth-abundant precursors instead of scarce, toxic, and nondegradable components existing in current systems must be a priority in future years. Cellulose is the most abundant biopolymer on earth. Their crystalline constituents designated as cellulose nanocrystals (CNC) have been studied as functional materials due to their excellent structural and chemical properties. This review covers a recent collection of works on innocuous CNC-based materials with special attention to the fabrication methodologies of electrodes, electrolytes, membranes, and separators. The implementation of these CNC-derived materials in sustainable energy conversion and storage systems is also discussed.