Tailoring the Voltage Gap of Organic Battery Materials Based on a Multi‐Electron Redox Chemistry
Fei Zhang, Yajuan Cheng, Zhihui Niu, Jing Ye, Gaole Dai, Xiaohong Zhang, Yu Zhao
Abstract
Abstract Redox‐active organics based on a multi‐electron mechanism are of great interest in battery electrode materials as they are capable of delivering high capacity per molecular weight. However, most of such organics shows huge voltage gap that is inherited from their stepwise redox reactions occurring in the same conjugated redox moiety. This study focuses on the voltage tailoring of polymeric dihydrophenazine derivative, which shows high specific capacity as a cathode electrode material and decent cycling stability, but suffers huge voltage gap of ca. 0.8 V. We demonstrate a strategy to modify the voltage gap of dihydrophenazine derivatives through the incorporation of functional groups with different electron affinity near the redox moiety. The as‐designed dihydrophenazine derivatives are further copolymerized to yield a polymeric material with significantly smoothened charge‐discharge profiles and good capacity retention. We further demonstrate through theoretical calculation based on density‐functional theory that the substitute site and types of functional groups are of great importance in voltage tailoring as well as structural stability of the dihydrophenazine derivatives.