Molecular Engineering Strategies for Organic Pre-Sodiation: Progress and Challenges.

Pre-sodiation, which is capable of supplying additional active sodium sources to sodium-ion batteries (SIBs), has been widely accepted as one of the most promising approaches to address the issue of active sodium loss during initial charging and subsequent cycling. Organic materials, with their design flexibility and abundant sources, are well-suited for large-scale applications. To achieve effective organic pre-sodiation, precise control over reaction potential is essential. In view of this, molecular engineering strategies are developed to mediate the pre-sodiation potential of organic materials for efficient pre-sodiation. Nevertheless, a comprehensive review of molecular engineering in organic pre-sodiation is still lacking. This timely review aims to present the crucial role of molecular engineering in organic pre-sodiation and provide an up-to-date overview of this field. After the showcasing of fundamental details of molecular engineering in organic pre-sodiation, recent advances in modifying oxidation decomposition/reduction potentials of organic pre-sodiation materials are briefly introduced, with a focus on the structure-activity relationship between functional group modifications and pre-sodiation potential. Future challenges and directions for developing next-generation organic pre-sodiation technologies are also reviewed. The current review provides important insights into molecular engineering in organic pre-sodiation, guiding the development of next-generation technologies of SIBs.