# Research on the Current Development Status of Redox Flow Batteries

## TL;DR

This paper reviews the current state and challenges of redox flow battery technologies, focusing on their development and potential for large-scale energy storage.

## Contribution

The paper systematically reviews recent innovations in flow battery materials and discusses emerging organic redox flow batteries.

## Key findings

- All-vanadium, iron-chromium, and zinc-based redox flow batteries each face distinct commercialization challenges.
- Recent research has focused on modifying key materials to overcome technical limitations in flow battery performance.
- Emerging organic redox flow batteries are identified as a promising area for future development.

## Abstract

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.