Additives to the electrolyte make them work from -40 ºF to 140 ºF (-40 ºC to 60 ºC)

The next big thing on battery tech is undeniably related to solid-state technology. Even John Goodenough – father of the lithium-ion batteries – is researching them. But it seems regular li-ion will also be perfect in what depends on PNNL (Pacific Northwest National Laboratory) scientists. They have managed to increase the working temperature range of these batteries, which now work well from -40 ºF to 140 ºF (-40 ºC to 60 ºC).

What was the magic, you may ask? Additives to the electrolyte. In fact, lots of them. 

The electrolyte is the element that allows the electrodes to react with each other. Depending on the temperature, it can be more or less efficient, hence the advantage of EVs with battery thermal management.

What the researchers from PNNL achieved was to combine multiple additives that allow the batteries to work well in temperatures in which they normally wouldn’t.

Cold weather is a known enemy of EVs, for example. What the additive combination accomplished was an “enhanced discharging performance at -40 ºC (-40 ºF)”.

Since EVs are still not very popular in desertic areas, people are not aware that extreme heats are not friendly with their performance either. The additive combination helps with that by bringing “improved cycling stability at 60 ºC (140 ºF)”.

The multiple additives combination acts by forming “highly conductive, uniform, and compact passivating films” around both the anode and the cathode.

The additives that were combined to create such a marvel for li-ion batteries are described in the study, published by ACS - Applied Materials and Interfaces. Really very technical stuff that will probably amuse people that love chemistry, but not everyone else.

We have no idea when the development will be applied to production li-ion cells. Considering the advantages presented, it is probably just a matter of more testing to check for any possible adverse effects.

If there is none, we’ll soon have better batteries for our EVs. If solid-state cells do not become viable before that, of course.

Source: ACS - Applied Materials and Interfaces via Green Car Congress