High‐Entropy Polymer Electrode for Fast Rechargeable Batteries

ABSTRACT Polymer electrode materials possess the advantages of sustainability, abundant resources, and structural adjustability, yet suffer from poor rate capability and cycling stability. Herein, we propose a concept of molecular structure entropy for the development of a high‐entropy polymer (HEP), wherein molecular structure entropy exerts a significant regulatory effect on the physicochemical and electrochemical performance of the resulting polymer. For sodium‐based batteries, the Na||HEP cell delivers a high reversible capacity of 167.7 mAh g −1 at a current density of 1 A g −1 , a long cycling stability of 5000 cycles, and a high‐rate capability of 111.9 mAh g −1 at a current density of 10 A g −1 , outperforming the low‐entropy polymer. Moreover, the all‐organic battery shows a long stability of 15 000 cycles, corresponding to a continuous running time exceeding 200 days. This work sets a precedent for HEP electrodes and establishes a foundation for their further research.