All cars suffer when mercury levels drop, but electric vehicles suffer greater than most because radiators draw more energy and batteries charge more slowly as the liquid electrolyte inside thickens. Chicago drivers learned this the hard way last January after driving multiple Teslas failed to charge during deep freeze.
One start, South 8 Technologies, claims it might make charging more reliable at low temperatures by filling batteries with a pressurized liquid gas electrolyte as a substitute of a liquid one. It hopes to reduce the cost of lithium-ion batteries by 30%.
For automakers, if these savings prove true, giving them up could also be too good. “The battery costs about a third of the entire car,” CEO Tom Stepien told TechCrunch.
South 8 says its manufacturing technique can reduce the size of some of the costliest parts of a battery factory. By injecting pressurized gas into the cell, South 8 can prevent the electrolyte from freezing to -100 degrees C, well below point at which nearly every other solvent turned into a solid.
“At -40 degrees C, we retain 75% of the energy capacity,” Stępień said. “Everything else is a brick.”
The company recently raised recent funding from Porsche Ventures in the form of a SAFE note, which can be used in the Series B round the company is starting to raise. Stepien said he couldn’t disclose the size of Porsche’s investment.
Stepien said Porsche seemed primarily interested in the South 8’s low-temperature performance. “They want to keep their finger on the pulse and know where the situation is going,” he said. Previous investors include LG, Anzu Partners and Lockheed. The startup was created as a result of research at the University of California, San Diego, which is mainly a paradise for electric vehicles it froze recently there in 1963
South 8’s core technology, which it calls LiGas, is based on gas, which is mostly used as a refrigerant. (Early scientific works published by the founding team suggests it is difluoromethylene, otherwise referred to as R-32.) However, introducing pressurized electrolyte into the cell presents several challenges. First, this approach only works with cylindrical cells, similar to those used in Teslas, Rivians, and Lucids. Currently, most automotive manufacturers use prismatic or pouch cells. Stępień said that the company will think about using this technology in prismatic cells in the future because they have a rigid can, while pouch cells do not have them, so they are not an option.
In cylindrical cells, the South 8 pressurized electrolyte requires the end caps to be stronger. The top cap also requires welding and requires a recent design that features a valve through which the electrolyte is injected.
All of this implies different hardware, which poses a barrier to adoption given the billions battery makers have invested in their gigafactories. But Stepien hopes South 8’s technology will ultimately translate into savings that can be too great to ignore.
First, Stepien said South 8’s technology will speed up production times because it might shorten the forming cycle during which batteries are first charged and discharged. This process can take several days and helps form a layer on the anodes that helps the battery reach its potential. Stepien said South 8 could cut that point by 90%.
“Our standard protocol for the cells we produce for our customers was roughly 100 hours. We conducted tests and didn’t observe any difference in performance after 10 hours,” Stępień said. The gas in the cells is itself a potent greenhouse gas, causing more than 600 times more global warming than an equivalent amount of carbon dioxide, study finds IPCC. If billions of cells are produced from the electrolyte, battery recyclers will have to add recent steps to their process to ensure the gas does not escape into the atmosphere. Recyclers have similar protocols for dealing with air con and refrigerator compressors, although on a much smaller scale. However, if South 8 may help develop a recycling solution while reducing the number of cells needed for cold-climate electric vehicles, the liquefied gas electrolyte could have a net climate profit.