Boosting electric car battery performance with a salt bath

By Ali Green

Range anxiety or EV (electric vehicle) anxiety – yes, the phenomena has a name! – is a very real and troublesome challenge for electric vehicle drivers. So much so, the Norwegian equivalent for ‘range anxiety’, rekkeviddeangst, was determined to be the second most popular word of the year in 2013. For those not up to speed on electric car terminology, range anxiety is when a driver of an electric car becomes anxious or stressed that their vehicle’s battery will run out of power before the destination or charging point can be reached.

Obviously, finding a cost effective solution to EV anxiety is high on the electric vehicle industry’s agenda, and will greatly impact the way drivers use electric cars. There have even been apps created that calculate an EVs range and prevent a vehicle expiring mid-trip. The current list of strategies to combat range anxiety includes developing a more extensive charging station infrastructure, using range extenders, and battery swapping.

And now thanks to our battery innovators we can add to that list: salt baths.

The battery scientists have just published a research paper in Nature Communications that shows the value in pre-treating a battery’s lithium metal electrodes with an electrolyte salt solution before its fabrication.

The simple technique involves the immersion of lithium metal electrodes in an electrolyte bath containing a mixture of ionic liquids and lithium salts prior to a battery being assembled. It could hold the key to developing the next generation of energy storage solutions. Ultimately, our scientists hope it will solve the issue or ‘range anxiety’ and disrupt the entire electric vehicle industry.

The pre-treatment process has been demonstrated to extend battery life to a point where electric vehicles will soon have the same range capacity as their traditional petrol counterparts.

The research, which formed a large part of Dr Andrew Basile’s doctoral thesis with RMIT University, investigated the battery processes occurring at lithium metal. Working closely with our researcher Dr Anand Bhatt, Andrew discovered that pre-treating the electrodes before fabrication stage reduces the breakdown of electrolytes during operation, which is what determines the battery’s increased performance and lifetime.

The process uses specially developed Room Temperature Ionic Liquid (RTIL) to deposit a protective film onto the surface of electrodes that helps stabilise the lithium metal and the battery when in operation. RTIL comes in a range of chemical compositions. The unique class of material is clear, colourless and odourless. It is also non-flammable, which means exploding laptops could be a thing of the past. We hold the patents on these unique materials to both pre-treat and cycle batteries with them.

The salt bath process creates batteries with charge efficiency greatly exceeding standard lithium batteries and potentially outperforming other commercial batteries. What’s more, it is readily transferable to existing manufacturing processes making it easily adopted by manufacturers.

The team of energy and manufacturing scientists is currently developing batteries based on this technology, and are looking for partners to help bring these materials and devices to market.

So look out EV industry – you’re about to be disrupted! And we think that pretty soon, thanks to this new and simple technique, rekkeviddetilfredshet (range satisfaction) could become a strong contender for Norwegian word of the year!

You can read the Nature Communication paper “Stabilizing lithium metal using ionic liquids for long-lived batteries” here.