Abstract
The need for affordable, durable and safe large-scale energy storage systems is rapidly growing with the increased deployment of solar and wind-based electricity generation. Aqueous redox flow batteries have the essential characteristics to meet the requirements for such energy storage systems. The past decade has seen considerable research into the scope and challenges of many types of redox materials for this application. The research for the next generation chemistries and systems must focus on lowering redox material cost and increasing durability. It would be beneficial to focus on inexpensive materials such as iron salts and redox couples based on small organic molecules that have shown significant promise. We must also advance our understanding of the factors affecting the capacity fade in aqueous systems, specifically relating to chemical stability, side reactions, and crossover. To this end, the challenge is to harness the advantages of the various organic molecular classes, substituent strategies and cell configurations to enhance the durability of future systems. In addition to low materials costs and durability, power density and efficiency are paramount to achieving low systems costs. The presentation will describe the need for a holistic approach to the challenges in designing next generation systems to meet the needs of rapidly emerging markets.