Porsche invests in battery startup South 8 to improve electric vehicle performance in cold weather

All cars suffer when the mercury drops, but electric vehicles suffer more than most because heaters use more energy and batteries charge more slowly as the liquid electrolyte inside thickens. Chicago drivers found out the hard way last January, after many Teslas failed to charge during a deep freeze.

One startup, South 8 Technologies, says it can make cold-weather charging more reliable by filling batteries with a pressurized liquefied gas electrolyte instead of a liquid electrolyte. In doing so, it hopes to reduce the cost of lithium-ion batteries by 30%.

For automakers, if these savings materialize, they could be too good to pass up. “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 most expensive parts of a battery factory. And by injecting pressurized gas into the cell, South 8 can prevent the electrolyte from freezing down to –100 degrees Celsius, well below the point at which almost all other solvents have 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 attracted new funding from Porsche Ventures in the form of a SAFE rating, which will be applied to a Series B funding round that the company is beginning to raise. Stepien said he could not disclose the amount of Porsche’s investment.

Porsche seemed primarily interested in the South 8’s low-temperature performance, Stepien said. “They want to stay tuned to 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 haven — it last froze there in 1963.

South 8’s core technology, called LiGas, is based on a gas most commonly used as a refrigerant. (Early published scientific work by the founding team suggests it is difluoromethylene, also known as R-32.) Introducing the electrolyte under pressure into the cell presents some challenges, however. First, the approach only works with cylindrical cells, the type used in Teslas, Rivians and Lucids. Today, most automobile manufacturers use prismatic or pocket cells. Stepien said the company would consider applying this technology to prismatic cells in the future, because they have a rigid box, but pocket cells do not, so they are ruled out.

In cylindrical cells, the pressurized electrolyte of South 8 requires the tips to be stronger. The top cap also needs to be soldered and requires a redesign to include a valve through which the electrolyte is injected.

All of this involves different equipment, which poses a barrier to adoption given the billions battery makers have invested in their gigafactories. Still, Stepien hopes South 8’s technology will ultimately result in savings too big to ignore.

On the one hand, Stepien said South 8’s technology will speed up production time because it can reduce the training cycle, during which batteries are first charged and discharged. The process can take days and helps form a layer on top of the anodes that helps the battery reach its potential. Stepien said South 8 could reduce that time by 90%.

“Our standard protocol here was around 100 hours for the cells we make for our customers. We did some testing and saw no difference in performance with 10 hours,” Stepien said. The gas in cells is itself a potent greenhouse gas, generating more than 600 times more global warming than an equivalent amount of carbon dioxide, according to the IPCC. If billions of cells were to be manufactured with this electrolyte, battery recyclers would need to add new steps to their process to ensure the gas does not escape into the atmosphere. Recyclers have similar protocols for handling air conditioning and refrigerator compressors, but on a much smaller scale. Still, if South 8 can help develop a recycling solution while reducing the number of cells needed for cold-climate electric vehicles, their liquefied gas electrolyte could be a net climate benefit.