Polestar 5 XFC Demo Electric Sedan Shows Off New Extreme Fast Charging Tech

The goal for manufacturers of EVs is to ultimately make the charging experience basically the same as filling up an ICE-powered vehicle. Right now, even the best all-electric vehicles will take up to 30 to 40 minutes to top up most of the way, as many are limited to under 300 kW of DC fast charging. Now, it appears that Polestar is closing in on the next step of battery technology: extreme fast charging (XFC). Partnering with StoreDot, Polestar has built an electric Polestar 5 sedan with a battery pack capable of charging from 10 percent state of charge (SOC) to 80 percent in nearly the same time as it takes to fill up the average car.

Why Is This A Big Deal? We’ve Been Promised This Before

See All 25 Photos25

It seems that EV range anxiety has been well forgotten by most people when it comes to EVs. Today, the issue is related to charger anxiety in both locating one that works reliably, and the amount of time spent waiting for their all-electric to charge on a DC fast charger. While faster than before, the average time spent at a public fast charger is anywhere between 30 to 40 minutes to get from 10 percent SOC to 80 percent.

That’s still a long time, especially when you compare that time to filling up the fuel tank of most ICE-powered vehicles, and the prevalence and reliability of gas stations. That’s why XFC is the holy grail of EV and battery technology at this point. If charging to gain 200 miles or more of range is the same amount of time to fill up a fuel tank, then the latest hurdle to EV ownership will vanish from the conversation just like range anxiety has. This demo by Polestar has been shown to charge an electric Polestar 5 sedan from that 10 to 80 percent SOC in just 10 minutes as these silicon-dominate cells—as StoreDot refers to them—can start at 310-kW and have topped at taking in 370-kW of power up to the 80 percent mark.

While we have seen lab-scale batteries achieve some rather fast charging rates, nothing has yet made it to market. That’s why this news from Polestar is a huge deal: it’s not just a lab-scale demonstrator. This is a real vehicle built with a real-world battery pack capacity.

A Real Battery Pack Scale Demo

Yes, the demonstration by Polestar and StoreDot isn’t just a single cell in a lab that’s then estimated to an equivalent vehicle battery pack. Within the structure of the Polestar 5 demo vehicle is a battery pack with a real-world capacity of 77-kWh. While that is smaller than the rumored 100-kWh plus pack the 5 will supposedly come with, Polestar and StoreDot say the capability of expanding the pack to the same capacity is possible. What’s even better is that the rate of charge is consistent through the charge time. Polestar says that it's possible to stop at a public fast charger at 50 percent SOC and only need about five minutes to reach 80 percent, as the SOC no longer affects the rate of this silicon-dominate cells.

Wait, What Kind Of Cell?

See All 25 Photos25

This is the other interesting part of these StoreDot cells. Rather than use Nickel-Manganese-Cobalt (NMC) based Lithium-Ion or Lithium-Iron-Phosphate (LFP or LiFePo4) cells, these cells use an anode (the positive side of a battery) made from a concentration of silicon greater than 40 percent while the cathode (the negative side) remains a nickel layer while it continues to use lithium for the electrolyte. Previously, silicon-based anodes were prohibitive as silicon is fragile to the mechanical stresses caused by expansion of the silicon during charging and can swell up (by up to 400 percent, according to StoreDot). This is on top of the challenges of reliable cycle life and building the silicon anode.

That said, it does offer a huge advantage over the typical graphite anode lithium-based cells use. Where you need six atoms of graphite to hold a single lithium atom, a single silicon atom holds four lithium atoms. This means that silicon anodes are more energy dense and can lead to physically smaller batteries and, potentially, lighter battery packs. It also means that battery packs can become cheaper. According to S&P Global in a 2023 report, “the variable cost of silicon is less than $2 per kWh” while “graphite is $7 per kWh.”

According to StoreDot, its proprietary cell can control the swelling and expanding issues inherent to silicon anodes. Even more impressive is that this rate of charge of up to 370-kW was also done without any special cooling and the only change made from the Polestar 5 was installing the 77-kWh StoreDot battery pack. "This is proof that we can now charge at these speeds in a standard car. We didn't add anything new outside the battery pack. It still had the original cooling pump and fan," said Jens Groot, battery system chief engineer at Polestar.

Great, When Do We Get It?

That’s the only unfortunate part of the story. While it is a reality on this prototype, Polestar and Jens says that it’s still a little way off. "We typically have a development cycle of two to three years, so I'd say we could put this into production within that time period,” Jens said in a release from Polestar. This means that we probably won’t see StoreDot silicon-dominate batteries in the first Polestars until sometime between 2026 and 2027 and the first Polestar 5 sedan will most likely still have a standard NMC battery pack. Despite that, this is still encouraging news and something that will most likely become reality, unlike many other lab-scale batteries capable of XFC charging rates.