Porsche announces high-performance battery manufacturing JV

German high-performance automaker Porsche announced over the weekend that it was forming a joint venture with German lithium-ion battery specialist Custom Cells, to develop car batteries with higher energy density.

Rumours of a collaboration between Porsche and Custom Cells have been circulating for over a year, now, and according to an announcement published over the weekend, the partnership has finally reached official status.

Porsche is reportedly investing a high, double-digit million-euro amount into the joint venture and will take an 83.75% stake in the resulting Cellforce company.

With a factory to be built in Tübingen, Germany, Cellforce will be focusing less on high production volume and more on high performance.

To that end, batteries produced by Cellforce will use silicon as opposed to graphite for the anode material, allowing for higher energy density and a more compact battery.

“Together we are developing a new generation of batteries: The energy density will be around 40 percent higher than that of the powerful Taycan cell,” said Porsche CEO Oliver Blume in an interview with German newspaper, Welt am Sonntag.

“Today the Taycan is charged from five to 80% in 22.5 minutes. The high-performance cells can be charged in less than 15 minutes.”

The promised range of the new batteries is also set to increase, by around 100-kilometres, and from 2024 the batteries will be built in small series for around 1,000 vehicles per year.

In a separate interview with ArsTechnica, Michael Steiner, member of the executive board, R&D at Porsche, echoed the company’s plans for a smaller run, explaining that the batteries were not designed for just any old vehicle.

“In terms of production, [it] will be small compared to all the gigafactories, you know, so we are looking forward to have around 100 MWh a year as production capacity – it could be slightly more,” Steiner explained to ArsTechnica.

“In terms of cars it should fit for, let me say, 1,000 cars a year. The kind of cells we look for are designed for motorsports and for high-performance derivatives of existing cars, so it’s a very tailored cell technology for high-performance solutions.”

In addition to higher density and reduced charging times, Porsche hopes that the new batteries will also be able to operate at a higher temperature than current lithium-ion battery cells.

“Today’s cell chemistry is able to [operate at] 50˚C, maybe slightly higher, and we are looking for temperatures above 70˚C that support superfast charging but also superfast driving,” Steiner told ArsTechnica.

Conversely, the new battery chemistry does not operate well at temperatures below freezing – certainly a problem for road vehicles, but not a problem for race cars, further isolating the role Cellforce will play moving forward.