Rui Luo, Xu Xie, Xin-rui Xiao, Nan Zhang, Jie Yang, Yong Wang
Cellulose, the most abundant renewable biobased polymer on Earth, is renowned for its biodegradability, low toxicity, and excellent mechanical properties. As dielectric materials increasingly move toward green and sustainable development, cellulose and its derivatives have emerged as promising alternatives. However, their dielectric properties depend mainly on microstructure, crystallinity, and aggregation state, which vary notably across cellulose matrices. This review first outlines the fundamental mechanisms of dielectric energy storage, highlighting cellulose structure's role in regulating key performance parameters. It then analyzes the structure-dielectric property relationship of cellulose and its derivatives, focusing on molecular arrangement, intermolecular interactions, and aggregation. Further, it reviews recent advances in three preparation strategies (molecular design, functional filler incorporation, multilayer construction), emphasizing their regulation mechanisms and advantages. Finally, it discusses limitations, challenges, and future trends. This review aims to provide references for the development of cellulose-based dielectric materials toward practical applications in flexible electronics and energy storage systems.