Bacterial cellulose: A versatile 3D nanostructure advancing electrode engineering for high-performance capacitive deionization

Capacitive deionization (CDI) is a promising technology for addressing global freshwater scarcity, and bacterial cellulose (BC), with its unique 3D nanostructure and sustainable nature, has emerged as an ideal material for CDI and faradic CDI (FDI) applications by enhancing desalination efficiency with minimal cost and manufacturing pollution. Despite these advantages, a comprehensive understanding of how BC's structural characteristics influence CDI and FDI performance is still lacking. This review, therefore, systematically evaluates recent advances in BC-derived materials for CDI, focusing on i) BC-derived carbon for electric double layer (EDL)-based CDI and FDI, ii) how its key properties (e.g., high conductivity, 3D networks, freestanding nature) address critical challenges (e.g., charge/mass transfer) of CDI/FDI, and iii) its potential to enable innovative cell designs like flow-through architectures. This review aims to provide fundamental principles and guidelines for optimizing BC-based CDI electrodes, paving the way for future innovations in BC-based CDI.