Carbonyl-rich organic cathodes for advanced aqueous batteries: progress and perspectives

Abstract

Aqueous batteries have garnered significant attention as compelling contenders for large-scale energy storage owing to their inherent safety, cost-effectiveness, and environmental sustainability. Significant endeavors have been dedicated to develop redox-active organic cathode materials, which is considered a crucial factor driving the development of aqueous batteries. Among various cathodes, carbonyl-rich organic compounds demonstrate exceptional potential in view of their strong electroactivity, ion-coupling sensitivity and structural versatility. This mini-review aims to provide a comprehensive understanding on the recent advancements in advanced carbonyl-rich organic materials for aqueous batteries. Firstly, we systematically categorize carbonyl-rich organic materials based on their molecular architecture: small molecules, polymers, and covalent organic frameworks, while elaborating their molecular design strategies and fundamental structure–performance relationships. Subsequently, we thoroughly explore their electrochemical applications in various aqueous batteries, including both metal-ion (e.g., Zn²⁺, Al³⁺, Ca²⁺, Mg²⁺) and non-metallic ion (e.g., H⁺, NH₄⁺) batteries. Furthermore, we conduct a systematic comparison of key performance metrics (capacity, voltage, rate capability, and cycling stability) for these carbonyl-rich organic cathodes in different aqueous batteries. Finally, critical challenges and future perspectives are summarized to fully unlock the potential of carbonyl-rich organic cathodes in next-generation high-performance aqueous batteries.