Progress of organic, inorganic redox flow battery and mechanism of electrode reaction

With the deployment of renewable energy and the increasing demand for power grid modernization, redox flow battery has attracted a lot of research interest in recent years. Among the available energy storage technologies, the redox flow battery is considered the most promising candidate battery due to its unlimited capacity, design flexibility, and safety. In this review, we summarize the latest progress and improvement strategies of common inorganic redox flow batteries, such as vanadium redox flow batteries, iron-chromium redox flow batteries, and zinc-based redox flow batteries, including electrolyte, membrane, electrode, structure design, etc. In addition, we introduce the latest progress in aqueous and nonaqueous organic redox flow batteries. We also focus on the modification mechanism, optimization design, improvement strategy, and modeling method of the redox flow battery reaction. Finally, this review presents a brief summary, challenges, and perspectives of the redox flow battery.