‘Ion jelly’ for better, cheaper batteries

Scientists in Portugal say they have created an ionic substance that could lower the cost and environmental impact of batteries, fuel cells and solar cells.

Susana Barreiros and her colleagues from the New University of Lisbon accidentally dissolved gelatin into a liquid composed of positively and negatively charged ions to produce what they called “ion jelly.”

Tests involving simple electrical circuits showed that the resulting substance conducted electricity, though not as well as an ionic liquid by itself.

Ionic liquids are considered stable and non-flammable, which makes them ideal replacements for the solid materials currently used to separate charged electrodes such as those found in batteries.

The process of converting ionic liquids into solids, however, tends to be an expensive one because the liquids melt at or below room temperature. And when the cooled liquids harden, they tend to form glass, which doesn’t have the structural arrangement needed to carry an electrical current.

Battery researchers also have to cope with the fact that the active materials in the electrodes react with the electrolyte and give off heat. Coating the electrode surfaces with protective films on the electrode surfaces is necessary to ensure that the battery is safe to use, does not overheat, and has a long lifespan.

Last year ExxonMobil’s (NYSE: XOM) chemical affiliate Tonen reported it was developing heat-resistant films for hybrid and electric vehicle batteries (see Exxon’s Tonen now producing a lithium ion separator film).

And in April, Milwaukee-based Johnson Controls-Saft Advanced Power Solutions and San Diego's Maxwell Technologies (Nasdaq: MXWL) announced they would collaborate on developing more effective and energy-efficient lithium-ion battery electrodes (see Johnson Controls-Saft, Maxwell Tech collaborate on batteries.

The Portuguese researchers are looking at using different types of ionic liquids to make ion jellies that would be specific substitutes for solids currently used as conductors.

The study by Barreiros and her colleagues appears in the journal ChemComm.