Aqueous iron-based redox flow batteries for large-scale energy storage

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Iron-based aqueous redox flow batteries (ARFBs) are promising for large-scale energy storage due to safety, cost, and scalability.
• Key challenges include hydrogen evolution, poor reversibility in metal deposition/stripping, and dendrite formation in hybrid systems.
• All-soluble ARFBs face limitations in redox species solubility and electrolyte stability.

Purpose of the Study:

• To provide a comprehensive overview of iron-based ARFBs.
• To categorize ARFBs into dissolution-deposition and all-soluble systems.
• To highlight recent advancements and explore future research directions.

Main Methods:

• Review of existing literature on iron-based ARFBs.
• Categorization of ARFBs based on operational mechanisms.
• Analysis of strategies for overcoming performance limitations.

Main Results:

• Identified critical challenges in iron-based ARFBs: hydrogen evolution, metal deposition/stripping reversibility, dendrite formation, and solubility/stability issues.
• Discussed various strategies including electrolyte, electrode, and separator modifications, and flow stack optimization.
• Categorized systems into dissolution-deposition and all-soluble types.

Conclusions:

• Iron-based ARFBs require further research in materials, system design, electrochemistry, and interdisciplinary approaches.
• Addressing current limitations is crucial for realizing the potential of ARFBs in large-scale energy storage.
• Continued development is supported by focusing on innovation in key research areas.