Aqueous Zn−organic batteries: Electrochemistry and design strategies

Abstract

Organic electroactive materials are increasingly recognized as promising cathode materials for aqueous zinc–ion batteries (AZIBs), owing to their structural diversity and renewable nature. Despite this, the electrochemistry of these organic cathodes in AZIBs is still less than optimal, particularly in aspects such as output voltage, cyclability, and rate performance. In this review, we provide an overview of the evolutionary history of organic cathodes in AZIBs and elucidate their charge-storage mechanisms. We then delve into the strategies to overcome the prevailing challenges faced by aqueous Zn−organic batteries, including low achievable capacity and output voltage, poor cycling stability, and rate performance. Design strategies to enhance cell performance include tailoring molecular structure, engineering electrode microstructure, and modulation of electrolyte composition. Finally, we highlight that future research directions should cover performance evaluation under practical conditions and the recycling and reuse of organic electrode materials.