Liquid energy storage blends battery and supercap benefits

A researcher at TU Graz says it is possible to combine the high-energy density of batteries with the high-power output of supercapacitors using liquid energy storage materials.

“Batteries release energy so slowly and take so long to charge because their energy storage materials are solid. This make it difficult for the ions to move. But as the ions in a supercapacitor move in a liquid, they are much more mobile,” explains TU Graz researcher Stefan Freunberger, pictured.

The redox active ionic liquid developed by Freunberger, in co-operation with a team from Montpellier University, consists of an organic salt that is liquid at 30°C.

“Our principle of an energy hybrid can offer enormous advantages,” Freunberger noted, “for example when applied in electric vehicles. So far, electric vehicles often carry a combination of different battery types or battery systems together with supercapacitors. If we had a single system that combines the benefits of both energy storage types, we could save considerable space and resources.”