Renewable lignin and its macromolecule derivatives: an emerging platform toward sustainable electrochemical energy storage

The conversion of natural renewable resources to high-value chemical products for electrochemical energy storage is becoming an effective measure to alleviate the energy crisis caused by the fossil shortage. As the second largest renewable biomass material in the world, lignin has been successfully utilized to construct sustainable energy storage devices (ESDs), both aqueous and organic ones. In this review, we provide a comprehensive overview of recent advances in the application of lignin-based/-derived macromolecules as key ESD components. A brief introduction to the origin and classification of lignin and its basic chemistry for electrochemical energy storage is first presented. The latest progress in lignin-based ESDs is then specifically elaborated on and discussed in detail from the perspective of organic electrodes, binders, electrolytes, and separators. Critical challenges and prospects in this area are put forward at the end, which is anticipated to shed light on the rational design of advanced lignin-based economic materials for sustainable development.