Research Progress on the Preparation of Flexible and Green Cellulose-Based Electrothermal Composites for Joule Heating Applications

Cellulose-based electrothermal composites (CETCs) are a type of functional material that combines a cellulose substrate with a heat generator to form multifunctional electrothermal composites with outstanding mechanical properties, biodegradability, flexibility, and Joule heating performance. The forms of cellulose include nanocellulose, cellulose fibers, cellulose paper, and cellulose fabrics. The heat generators include carbon-based materials (e.g., graphene and carbon nanotubes), metal nanowires, metal carbides/nitrides, and other conductive polymers. With the increasing demand for clean energy, comfortable heating, and green raw materials, CETCs are expected to become one of the most promising materials used in electric heating products. To provide the latest research and innovative strategies, this review introduces the methods used to prepare CETCs; these include vacuum filtration, freeze-drying, wet spinning, solution casting, coating, in situ polymerization, and deposition. Additionally, applications and prospects of cellulose-based electrothermal composites in wearable heaters, soft electrothermal actuators, deicers and defrosters, and agricultural films are presented.