Mechanism modulating the redox chemistry of hexaazatriphenylene‐based small molecules by push–pull electron effect for zinc‐ion batteries

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Abstract Organic compounds are promising electrode materials for aqueous zinc‐ion batteries (AZIBs) but largely suffer from poor rate and cycling performance. This work reports that the push–pull electron effect of organic compounds could be used to tune the electrochemical performance of AZIBs. Hexaazatriphenylene‐based (HATN) small molecules with different withdrawing or donating groups were synthesized and used as electrodes for AZIBs. Compared to the hydrogen atoms and electron‐donating methyl groups, the electron‐withdrawing fluorine atoms endow HATN‐based small molecule (HATN‐6F) with a much‐improved redox platform, rate performance and cycling stability. The fluorinated electrode HATN‐6F potently amplifies and stabilizes the kinetics of cation co‐(de)insertion reactions, concurrently enhancing the conductivity and electron affinity, resulting in improved rate performance and enhanced cycling stability. The combination of theoretical calculations and experimental characterization confirms that the fluorine‐rich peripheral environment effectively modifies the distribution of conjugated electrons in HATN, enhancing its affinity for zinc ions and improving its capacity for cations zinc storage. This work demonstrates a new avenue for the design and synthesis of organic electrode with excellent electrochemical performance for ZIBs.

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