Research on the Current Development Status of Redox Flow Batteries

In recent years, flow batteries have emerged as a crucial technological solution for large-scale energy storage, leveraging their unique power-capacity decoupling characteristics and long cycle life to demonstrate significant potential in applications such as renewable energy integration and grid frequency regulation. Based on differences in electrolyte systems, mainstream flow battery technologies are primarily categorized into three types: all-vanadium redox flow batteries (VRFBs), iron-chromium redox flow batteries (ICFBs), and zinc-based redox flow batteries (ZRFBs). However, each of these technologies faces critical challenges in practical commercialization: VRFBs are constrained by cost pressures due to fluctuations in vanadium resource prices and relatively low energy efficiency; ICFBs require urgent solutions to issues such as hydrogen evolution side reactions at the negative electrode and the sluggish kinetic responses of the Cr³⁺/Cr²⁺ redox couple; while ZRFBs grapple with safety concerns such as zinc dendrite growth and morphology instability. To overcome these technical bottlenecks, extensive innovative research has been conducted in key materials (electrodes, ion-exchange membranes, electrolytes). Against this backdrop, this paper systematically reviews recent advances in the modification and optimization of flow battery technologies and conducts an extended discussion on the emerging organic redox flow batteries in recent years.