Power play: New electrolyte means faster, more reliable batteries

28 July 2022

The development of a new, non-flammable electrolyte material could mean a safer and cheaper alternative to lithium-ion batteries and – thanks to the work of University of Queensland researchers – another step towards a cleaner energy future. 

Cross-sectional SEM image of the material
Cross-sectional SEM image of the material

Currently, most lithium and sodium batteries contain flammable electrolytes, but – in a paper published in the prestigious Nature Materials journal – researchers from UQ’s Australian Institute for Bioengineering and Nanotechnology (AIBN) and Deakin’s Institute for Frontier Materials found the safety and life-cycle of sodium batteries improved when these traditional solvents were swapped out.

Featuring key contributions from AIBN’s Dr Cheng Zhang and Professor Andrew Whittaker – as well as Deakin’s Dr Xiaoen Wang and Professor Maria Forsyth – the team found that their newly developed solid polymer electrolyte material transformed sodium batteries into a safer, cheaper, and more reliable power storage when compared to the lithium-ion batteries that dominate the market.

“This solid-state electrolyte material will enable us to create a new generation of solid batteries for use in electric cars, mobile phones and stationary energy storage like solar,” Dr Zhang said.

“Current batteries on the market generally use carbon-based electrode and liquid electrolyte, which has low capacity and is at risk of overheating.”

Deakin University’s Institute for Frontier Materials researcher Xiaoen Wang said the research team had taken a different approach to battery creation by using reactive sodium metal as an anode.

“This means we can increase battery capacity and in the process are developing safer electrolytes to ensure the safety of sodium batteries,” Dr Wang said.

It is the first time the fluorine-containing polymer has been used in solid-state batteries – having previously been used in biological applications – with reliable and long-lasting energy storage that helps reduce carbon emissions being the end goal. 

According to Wang, one of the main benefits in using sodium as an alternative source to lithium in battery production, is its low production cost.

"As lithium could become a rare commodity, the price of lithium batteries is high, while on the other hand, sodium resources are more abundant," Dr Wang said.

"Our polymer will support the use of sodium batteries, which are low cost when compared to lithium batteries."

One drawback of current sodium batteries is that they do not last for as long as lithium batteries and have a lower energy density. However, in pairing them with the new polymer electrolytes, they offer close to 1000 cycles, comparable to the current well-developed lithium batteries.

With further research, opportunities could be on the horizon for use in stationary energy storage such as solar or even in electric cars.

Small-scale testing of the batteries has been successful, with upscaling and prototyping coming soon.

This research was published in Nature Materials.