Tunable Redox‐Active Anhydride‐Based Linear Polymer as Organic Cathodes for Chemically Self‐Charging Aqueous Zinc–Ion Batteries

ABSTRACT Chemically self‐charging aqueous zinc‐ion batteries (AZIBs) have emerged as promising candidates for energy storage technologies owing to their environmental autonomy and structural simplicity. Nonetheless, the self‐charging performance is significantly compromised by the limited potential difference between cathodes and oxygen, as well as the unsatisfactory cycling stability. Herein, we synthesized three novel polymeric cathodes (PM‐E, NT‐E, and PT‐E) derived from distinct anhydride precursors for application in both AZIBs and chemical self‐charging AZIBs. Combined experimental and density functional theory (DFT) analyses indicate that the π‐conjugated aromatic ring structures in various anhydride derivatives modulate the zinc storage activity of the carbonyl group (C=O). PT‐E demonstrates superior electrochemical performance due to its optimal combination of band structure and molecular planarity, maintaining a specific capacity of 97.1 mAh g −1 at 1 A g −1 after 300 cycles for AZIBs. Particularly, the PT‐E cathode exhibits rechargeability through direct air oxidation without the external power supply; the discharged chemical self‐charging AZIBs can be recharged to 1.28 V after exposure to air for 12 h. Meanwhile, it demonstrates excellent compatibility with combined chemical/galvanostatic charging environments, exhibiting exceptional electrochemical reversibility. This study advances chemical self‐charging AZIBs technology while expanding the utilization scope of organic materials in autonomous energy storage systems.