All cars suffer when the mercury drops, but electric vehicles suffer more than most, as heaters draw more power and batteries charge more slowly as the liquid electrolyte inside thickens. Drivers in Chicago found that out the hard way last January after several Teslas failed to charge during a deep freeze.
A startup, South 8 Technologies, says it can make cold-weather charging more reliable by filling batteries with a pressurized, liquefied gas electrolyte instead of liquid. Along the way, it hopes to reduce the cost of lithium-ion batteries by 30%.
For automakers, if those savings pan out, it might be too good to pass up. “The battery costs about a third of the entire car,” CEO Tom Stepien told TechCrunch.
South 8 claims its manufacturing technique can reduce the size of some of the most expensive parts of a battery plant. And by injecting pressurized gas into the cell, South 8 can prevent the electrolyte from freezing down to -100 degrees C, well below the point in which almost every other solvent has turned into a solid.
“At -40 degrees Celsius, we retain 75% of the energy capacity,” Stepien said. “Everything else is a brick.”
The company recently raised new funding from Porsche Ventures in the form of a SAFE note, which will be applied to a Series B round that the company is starting to raise. Stepien said he could not disclose the size of Porsche Ventures’ investment.
Porsche Ventures seemed primarily interested in the South 8’s low-temperature performance, Stepien said. “They want to keep their finger on the pulse of where things are going,” he said. LG, Anzu Partners and Lockheed are previous investors. The startup grew out of research at UC San Diego, which is basically an electric vehicle paradise. recently it froze there in 1963.
South 8’s core technology, which it calls LiGas, is based on a gas most commonly used as a refrigerant. (Early scientific work published (from the founding team suggests it’s difluoromethylene, otherwise known as R-32.) Getting the electrolyte under pressure into the cell, however, presents a few challenges. First, the approach only works with cylindrical cells, the kind used in Teslas, Rivians and Lucids. Today, most automotive manufacturers use prismatic cells or cases. Stepien said the company will consider applying the technology to prismatic cells in the future because they have a rigid box, but case cells don’t, so they’re off the table.
In cylindrical cells, South 8’s pressurized electrolyte requires the end caps to be stronger. The top cap also needs to be welded and requires a new design that includes a valve through which the electrolyte is injected.
All of this means different equipment, which is a barrier to data adoption of the billions battery makers have invested in their gigafactories. Still, Stepien hopes South 8’s technology will eventually translate into savings that are too big to ignore.
For one, Stepien said South 8’s technology will speed up production time because it can reduce the formation cycle, in which batteries are charged and discharged first. The process can take days and helps form a layer over the anodes that helps the battery reach its potential. Stepien said South 8 can cut that time by 90 percent.
“Our typical protocol here has been about 100 hours for cells we build for our customers. We tested and saw no difference in performance at 10 hours,” said Stepien. 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, IPCC. If billions of cells are made with the electrolyte, battery recyclers will have to add new steps to their process to ensure the gas doesn’t escape into the atmosphere. Recyclers have similar protocols for handling air conditioning compressors and refrigerators, albeit on a much smaller scale. However, if South 8 can help develop a recycling solution while also reducing the number of cells needed for cold-climate electric vehicles, their liquefied gas electrolyte could be a net climate boon.
Correction: Headline has been updated to note that Porsche Ventures is the investor.
