High‐Voltage Recyclable Organic Cathode Enabled by Heteroatomic Substitution for Aqueous Zinc‐Ion Batteries

Abstract

Abstract N‐type organic compounds present themselves as promising high‐capacity cathodes for aqueous Zn‐ion batteries. However, a common challenge is their working voltages often falling below 1 V versus Zn 2+ /Zn. To bridge this gap, a high‐voltage organic material is first developed, 5,6,11,12‐tetraazanaphthacene (TANC), using a heteroatomic substitution strategy. TANC feature a large π‐conjugated plane enriched with π−π interactions, which not only enhancing structural stability but also boosting charge transfer kinetics. The TANC cathode is achieved from its dihydro precursor, denoted as 2H‐TANC, via a facile in situ activation process within the battery itself. This electrochemical synthesis method is cost‐effective and environmentally friendly compared to traditional chemical method. The cathode shows a record‐high discharge voltage of 1.15 V (vs Zn 2+ /Zn) among n‐type organic materials and maintains cycling stability over 47,500 cycles. Furthermore, spent TANC electrodes can be efficiently recycled via a simple extraction process. The work marks a significant step toward the development of high‐voltage, affordable, and recyclable organic electrode materials, steering them to the forefront of future sustainable battery technologies.