Application of cellulose‐based hydrogel electrolytes in flexible batteries

Abstract Flexible energy storage devices have the advantages of portability and safety, and have great potential for developing electronic materials in the future. In flexible batteries, the electrolyte presents an essential role in the electrochemical performance and safety of the batteries. Hydrogel electrolyte materials are considered to be one of the ideal electrolyte materials due to their environmental friendliness, high safety, maneuverability, and innocuity. However, ordinary hydrogels often suffer some defects, such as insufficient ductility and poor water retention. Currently, many researchers report cellulose materials as reinforcing agents to improve the performance of hydrogels. In this paper, we review the recent application of cellulose in hydrogel‐based materials for energy storage technology and summarize the functions and properties of cellulose. In addition, we analyze the shortcomings of cellulose used in hydrogels and briefly describe the prospects of cellulose materials, hoping to contribute to the research in this field.