Extending π‐Conjugation and Integrating Multi‐Redox Centers into One Molecule for High‐Capacity Organic Cathodes
Zhaolei Wang, Qiao‐Yan Qi, Weize Jin, Xin Zhao, Xiaoyu Huang, Yongjun Li
Abstract
Abstract Structural diversity, designability, and eco‐friendliness make organic electrode materials appealing for next‐generation rechargeable batteries. However, most of them show low specific capacity and poor cycling stability, which limit their further application. To develop high‐capacity imide‐based cathode materials, three C 3 ‐symmetric triimides were designed. Systematic comparisons of these triimides as cathode materials revealed that extending π‐conjugation and incorporating multiple redox centers improved the cell performance in terms of specific capacity and cycling stability. In particular, a nitrogen‐rich heteroaromatic hexaazatrinaphthylene triimide (HATNTI‐Pr) with multiple active sites (imide and pyrazine) exhibited high specific capacity. Hybridized with graphene sheets, a HATNTI‐Pr‐based binder‐free cathode delivered a high practical capacity (317 mAh g −1 at 0.1 C), excellent cycling stability (80 % retention after 100 cycles), and considerable rate performance (75 mAh g −1 at 5 C). The energy storage mechanism of HATNTI‐Pr with up to nine Li + storage ability was investigated.