A Dye Could Power Scalable Batteries

A dye that glows yellow-green under ultraviolet light could be used in batteries to store power from renewable energy sources like solar and wind.

The dye, boron-dipyrromethene (BODIPY), is a potential candidate for use in redox flow batteries (RFBs). RFBs reversibly convert electrical energy to chemical energy. Unlike traditional rechargeable batteries, which store electricity internally in their redox pairs fixed on the two electrodes, RFBs store their energy externally in two flowing electrolytes. The energy capacity (a function of the volume of electrolyte) and power (a function of the size of the electrochemical cell stacks) are decoupled in the flow battery, providing design flexibility and economical scalability. Scaling up a redox flow battery’s storage capacity requires only enlarging the reservoirs of electrolyte solutions, not enlarging all of the battery’s components, says Timothy Cook, an assistant professor of chemistry at the State Univ. of New York, Buffalo.

Redox flow batteries have not been an area of intense interest because most commercial battery needs of late have focused on portability, Cook says. Most researchers have, therefore, been focused on technologies such as lithium-ion batteries. As interest in solar power and other renewables increases, though, companies are increasingly facing the problem of how to store energy generated during...