Nanocellulose-Based Flexible Electrodes for Energy Storage: Design Strategies, Performance Optimization, and Applications

Abstract Owing to its unique mechanical robustness and hierarchical structural characteristics, nanocellulose has emerged as an ideal substrate for flexible electrodes, addressing the urgent demands for lightweight design, high mechanical flexibility, and long operational lifespan in flexible energy storage devices. This review systematically summarizes the design strategies, performance optimization approaches, and recent application progress of nanocellulose-based flexible electrodes. First, preparation strategies including solution processing, template-assisted methods, and composite modification are discussed in detail, with particular emphasis on the role of multiscale structural engineering in enhancing electrochemical performance. Subsequently, key optimization strategies, including material hybridization, electrolyte matching, and surface modification, are examined, and the current research status of nanocellulose-based electrodes in supercapacitors, microsupercapacitors, and lithium-ion batteries is summarized. Finally, existing challenges, including the trade-off between electrical conductivity and mechanical flexibility as well as large-scale manufacturability, are identified, and future development directions are proposed. This work provides a theoretical framework and technical guidance for the performance optimization and industrial implementation of nanocellulose-based flexible electrodes, thereby facilitating the integration of flexible energy storage technologies into next-generation electronic devices.