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Dilution of the Electron Density in the π‐Conjugated Skeleton of Organic Cathode Materials Improves the Discharge Voltage
Author(s) -
Dai Gaole,
Gao Yehua,
Niu Zhihui,
He Ping,
Zhang Xiaohong,
Zhao Yu,
Zhou Haoshen
Publication year - 2020
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201903502
Subject(s) - conjugated system , redox , cathode , organic radical battery , carbazole , battery (electricity) , electrode , chemistry , chemical engineering , materials science , inorganic chemistry , photochemistry , electrochemistry , organic chemistry , polymer , power (physics) , physics , quantum mechanics , engineering
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.