Energy storage promise found in common chemical

A chemical used in everything from toothpaste to tennis court lines could also help store energy produced by renewable sources, according to new research by Australian scientists.

Yun Liu, a chemist and Associate Professor at the Australian National University (ANU), has discovered that  titanium dioxide, a chemical widely used as a whitening pigment in plastics, paints, creams and even in low-fat milk, could be useful for building energy storage devices.

Liu and her colleagues made the discovery after five years of searching to find the perfect material for using in energy storage devices called capacitors: a material that can store a lot of energy, minimise energy wastage and leakage, and work across a broad range of temperatures.

“It’s a very big problem,” Liu told ABC Online. “Generally, if a material has a high dielectric constant, the energy loss is high and the temperature stability is very low.”

But Liu and her team now believe they have found that titanium dioxide, manipulated at the molecular level, meets these conditions; with a dielectric constant that is substantially higher than other materials, excellent temperature independence and low levels of energy loss.

“We believe this work breaks through the log-jam associated with the practical development of…materials for use in large capacitors and high-energy-density storage devices,” they write in the journal Nature Materials .

The discovery could help overcome a major barrier to the large-scale use of renewable energy resources like solar and wind, helping to integrate them into existing power grids by balancing the power going into the grid with the demand for power at any given time.

“Our material performs significantly better than existing high dielectric constant materials so it has huge potential,” Liu told the ABC. “It’s like a dream come true.”

Liu believes the chemical could be used in solid-state ‘supercapacitors’ to store enormous amounts of energy, opening the door for innovation in the areas of renewable energy and clean electric transport.

Liu says the other major plus for titanium dioxide is that it’s “a very simple and abundant material,” found naturally around the world, and exported from Australia. “Australia currently dominates the market in this material,” adds Liu.

But they have a way to go before this becomes a reality. Liu and the team must first develop the practical applications from their research – the next step on a path that might lead to building functional capacitors using titanium dioxide.