Building stable small molecule imide cathodes toward ultralong-life aqueous zinc-organic batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2023-06, Vol.465, p.142824, Article 142824
• Main Authors: Li, Lei, Wang, Yongjiang, Gong, Wenbin, Lin, Meijin, Wei, Lei, Li, Qingwen, Zhang, Qichong, Sun, Litao
• Format: Article
• Language: English
• Subjects: Aqueous zinc batteries; Co-insertion mechanism; Imide derivatives; Organic cathodes; Ultralong cyclability
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.142824

•A perylene-based imide derivative with larger π-conjugated structure (2PDI) was prepared as electrode material.•The assembled 2PDI battery offered an ultralong cycling stability with 99.4% of capacity retention after 50 000 cycles at 3000 mA g−1.•Its mechanism of reversible co-insertion Zn2+/H+ are verified via electrochemical tests and ex-suit characterizations.•The most favorable structure of discharge products was further clarified and discussed to be (2PDI)2(H+)6(Zn2+). Organic carbonyl compounds as electrode materials have exhibited promising candidates for application in next-generation aqueous rechargeable batteries. However, a primary concern that is poor cycling performance are still remains due to high solubility of discharge products, which greatly limits their broader application. Herein, we developed a strategy to enhance the cyclability of aqueous zinc-organic batteries (AZOBs) by the terminal imidization and lateral π-system extension of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). This strategy resulted in a perylene-based imide derivative with larger π-conjugated structure (2PDI), significantly inhibiting the solubility in an aqueous electrolyte. As expected, 2PDI as cathode offered a discharge capacity of 72.8 mA h g−1 at a current density of 100 mA g−1, and even retaining 99.4% capacity after ultralong 50 000 cycles at 3000 mA g−1. Its mechanism of reversible co-insertion Zn2+/H+ at the carbonyl site was verified via electrochemical tests and ex-suit characterizations. Moreover, density functional theory calculation (DFT) also revealed this co-insertion mechanism.