标题：Dilution of the Electron Density in the pi-Conjugated Skeleton of Organic Cathode Materials Improves the Discharge Voltage
作者：Dai, Gaole; Gao, Yehua; Niu, Zhihui; He, Ping; Zhang, Xiaohong; Zhao, Yu; Zhou, Haoshen
作者机构：[Dai, Gaole; Gao, Yehua; Zhang, Xiaohong; Zhao, Yu] Soochow Univ, Jiangsu Key Lab Carbon Based Funct Mat, Inst Funct Nano & Soft Mat FUNSOM, 199 Renai 更多
通讯作者：Zhao, Y;Zhou, HS;Zhou, HS
通讯作者地址：[Zhao, Y]Soochow Univ, Jiangsu Key Lab Carbon Based Funct Mat, Inst Funct Nano & Soft Mat FUNSOM, 199 Renai Rd, Suzhou 215123, Jiangsu, Peoples R Chin 更多
关键词：aromaticity; electron delocalization; high voltage; indolocarbazole;; organic batteries
摘要：Organic compounds are promising candidates as battery materials because they can be sourced from sustainable resources, have tunable structures, and are cheap. However, the working voltage of battery cells containing organic compounds as positive electrodes is relatively lower than that of those containing an inorganic counterpart. In this work, a strategy was developed to increase the discharge voltage of battery cells by diluting the electron density of N-based redox centers in conjugated organic materials. In electron-rich heterocyclic compounds that utilize N as the redox center, pentatomic rings such as carbazole derivatives exhibited a higher atomic-dipole-moment-corrected Hirshfeld charge population compared with hexatomic rings, which led to a significant increase in the oxidation potential. As a result, polymeric indolocarbazole derivatives showed a high discharge voltage of 3.7-4.3 V vs. Li+/Li and good cycling performance. Such a strategy can be used to design high-voltage organic electrode materials containing other redox centers.