Salt bath could sooth electric vehicle 'range anxiety'

CSIRO, RMIT and QUT are developing a salt bath to increase battery life and performance

Despite sleek designs and the potential for long-term savings, Australia has not yet taken to the electric vehicle.

Only 942 fully electric vehicles were sold here last year, compared to the 1.1 million cars bought by Australians in the same period.

Cost is certainly a factor – Tesla recently unveiled a 'cheaper' version of their Model S for $108,300 – but limited range is a significant sticking point against wider adoption.

Tesla’s own home-use Wall Connector, installed directly into a 240v circuit, gives its vehicles 83 kilometres of range per hour of charge. That’s roughly the distance from one side of Sydney to the other.

CSIRO scientists, working with RMIT University and Queensland University of Technology, have now found a way to extend the life of lithium batteries, potentially removing the ‘range anxiety’ surrounding electric cars.

“The technology has the potential to improve electric vehicle drive range and battery charge to a point where electric vehicles will soon be competitive with traditional petrol vehicles in terms of drive range per charge,” said Dr Adam Best of CSIRO. “It could be the breakthrough needed for applications such as electric vehicles where concerns of ‘range anxiety’ are negated.”

Best’s team have demonstrated that pre-treating a battery’s lithium metal electrodes with an electrolyte salt solution improves a battery’s charge efficiency. The treatment also prevents the risk of fire and explosion, a well known rechargeable battery issue.

The process involves the immersion of lithium metal electrodes in an electrolyte bath containing a mixture of ionic liquids and lithium salts, before the battery is assembled.

The salt bath pre-treatment adds a protective film onto the surface of the electrode that helps stabilise the battery when in operation.

“Our research has shown by pre-treating lithium metal electrodes, we can create batteries with charge efficiency that greatly exceeds standard lithium batteries,” said Dr Best.

Batteries that were given the salt-bath treatment were also found to be able to spend up to a year on the shelf without loss of performance.

CSIRO holds patents on the electrolyte salt solutions with come in a range of chemical compositions.

“This approach could readily be translated to existing manufacturing processes and therefore accelerate the development of next-generation energy storage solutions,” said QUT's Associate Professor Anthony O’Mullane.

The team of scientists is now seeking commercial partners to help bring the batteries to market.