New battery technology for large-scale storage

RFBs were first built in the 1940s, and are considered a promising form of large-scale energy storage. Traditionally, they have been made using expensive metals and dangerous acids.

“This is not only extremely expensive, but the solution is highly corrosive, so that a specific membrane has to be used and the life-span of the battery is limited,” said Jena University’s Dr Martin Hager, one of the lead authors of a paper on the research.  

The new technology, described in the journal Nature, uses organic polymers for the electrodes, with a saline solution as the electrolyte. According to the researchers, these materials are cheaper and safer than those currently in use, yet comparable in efficiency.

“What’s new and innovative about our battery is that it can be produced at much less cost, while nearly reaching the capacity of traditional metal and acid containing systems,” said Hager.

The electrodes of RFBs come in a dissolved form, stored in two tanks to form the positive and negative terminals of the battery. Using pumps, the polymer solutions are transferred to an electrochemical cell, where they are then reduced or oxidized, thereby charging or discharging the battery. The cell is divided in two by a membrane to prevent the two electrolytes from mixing.