All cars suffer when the mercury drops, but electric vehicles suffer more than most because heaters use more power and batteries charge more slowly as the liquid electrolyte inside thickens. Drivers in Chicago found this out the hard way last January after many Teslas couldn't charge during a deep freeze.
One startup, South 8 Technologies, says that filling batteries with a pressurized, liquid gas electrolyte instead of a liquid electrolyte can make charging more reliable in cold weather. In doing so, it hopes to reduce the cost of lithium-ion batteries by 30%.
If those savings come to fruition, it may be too good for automakers to pass up. “The battery costs about a third of the entire car,” CEO Tom Stepien told JS.
South 8 claims 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 to -100 degrees Celsius, well below that temperature. the point with almost every other solvent turned into a solid.
“At -40 degrees Celsius we retain 75% of the energy capacity,” says Stepien. “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 beginning to raise. Stepien said he could not reveal the size of Porsche's investment.
Porsche seemed particularly interested in the South 8's performance at low temperatures, 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 EV paradise last frozen there in 1963.
South 8's core technology, which the company calls LiGas, is based on a gas typically used as a refrigerant. (Early scientific work published by the founding team suggests it is difluoromethylene, also known as R-32.) However, pressurizing the electrolyte in the cell poses a number of challenges. First, the approach only works with cylindrical cells, the kind used in Teslas, Rivians and Lucids. Today, most car manufacturers use prismatic cells or pouch cells. Stepien said the company would consider applying the technology to prismatic cells in the future, because they have a rigid sleeve, but pouch cells do not, so they are off the table.
In cylindrical cells, South 8's pressurized electrolyte requires the end caps to be stronger. The top cover must also be welded on and requires a new design with a valve through which the electrolyte is injected.
That all means different equipment, which poses an obstacle to adoption given the billions battery makers have invested in their gigafactories. Still, Stepien hopes South 8's technology will eventually translate into savings too big to ignore.
First, Stepien said South 8's technology will speed up production time because it can shorten the formation cycle, in which batteries are first charged and discharged. The process can take days and it helps form a layer on top of the anodes that allows the battery to reach its potential. Stepien said South 8 can reduce that time by 90%.
“Our standard protocol here has been about 100 hours for cells that we make for our customers. We did tests and after 10 hours we saw no difference in performance,” 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, the researchers said. IPCC. As billions of cells are manufactured 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 and refrigerator compressors, albeit on a much smaller scale. But if South 8 can help develop a recycling solution while reducing the number of cells needed for electric vehicles in cold climates, their liquefied gas electrolyte could be a net benefit to the climate.
