Development of Poly(naphthalene-diamine) as a Low-Cost, High-Performance Organic Cathode Material for Aqueous Zinc-Organic Batteries

Aqueous zinc-organic batteries (ZOBs) have attracted considerable attention due to their potential for low cost and high safety, representing a significant stride toward sustainable energy storage solutions. The development of such organic electrode materials (OEMs) is imperative to enhance the performance and viability of ZOBs for practical applications. In this study, we synthesized poly(naphthalene-diamine) (PDAN) through a chemical oxidative polymerization method and investigated the impact of different oxidizing agents on the structure and properties of PDAN. Notably, PDAN-F, synthesized using ferric chloride as an oxidizing agent, exhibits a distinctive ladder-shaped structure. The PDAN-F demonstrates a high reversible capacity of 286 mA h g–1 at a current density of 0.1 A g–1 and exceptional cycling stability (retaining 95% capacity after 2000 cycles at 2 A g–1). These performance metrics are comparable to those of previously reported, costly quinone and nitrogen-containing heterocyclic polymers. This work provides insights into the design of practical OEMs.