Expanding the Molecular Library for In Situ Polymerization: Design and Evaluation of Dithiafulvene- and Triphenylamine-Based Cathode Materials.

Developing organic electrode materials that combine high capacity with long-term stability remains a major challenge for next-generation rechargeable batteries. Here, we expand the molecular library for in situ polymerization by designing new organic molecules composed of redox-active dithiafulvene units combined with triphenylamine moieties. The synthesized molecules were structurally characterized by X-ray structural analysis and their redox properties clarified by electrochemical analysis. When applied as positive electrodes in lithium-ion batteries, molecules without benzoquinone substituents delivered discharge capacities close to their theoretical limits and exhibited remarkable cycling stability. In contrast, benzoquinone-substituted derivatives showed inferior stability, indicating the need for further molecular optimization. This study underscores the potential of in situ polymerization-based molecular design for advanced organic cathode materials and provides useful guidelines for the development of sustainable energy storage systems.