ONE OF THE ONGOING HURDLES with EVs is how long it takes to charge them up. People, quite simply, want to recharge their cars in about the same time as it currently takes to refuel an internal combustion engine car. And the general consensus is that’s about 10 minutes.
Well, now it seems that such fast charging may actually be possible.
Polestar and fast-charging battery pioneer StoreDot have successfully demonstrated the implementation of StoreDot’s Extreme Fast Charging (XFC) technology in a car for the first time, charging a Polestar 5 prototype from 10 to 80 percent in just 10 minutes. The fully driveable verification prototype saw a consistent charge rate starting at 310kW and rising to a peak in excess of 370kW at the end of charging.
This world-first demonstration of a 10-minute 10-80 percent extreme fast charge using silicon-dominant cells in a driveable vehicle – rather than individual cells in a laboratory environment – is the continuation of Polestar’s commitment to developing the best driving experience for the future through innovative technology partnerships. The specially commissioned 77kWh battery pack – which has the potential to be increased to at least 100kWh, could add 320 km of range to a mid-sized electric car in 10 minutes.
This XFC test by Polestar and StoreDot battery engineers was designed to demonstrate proof-of-concept for XFC battery technology that could be applied to future Polestar vehicles.
Thomas Ingenlath, Polestar CEO, says, “Time is one of life’s greatest luxuries, and as a manufacturer of luxury electric performance cars, we need to take the next step to address one of the biggest barriers to EV ownership – charging anxiety. With this new technology, on longer journeys when drivers do stop, they’ll be able to spend less time charging and be back on the road faster than before. In fact, that stop time will be more akin to what they experience with a petrol car today.”
StoreDot’s revolutionary XFC technology utilises silicon-dominant cells with an energy density on par with state-of-the-art NMC cells, and does not require specialist cooling systems in the vehicle. The experimental XFC battery’s modules have a structural function which, improves mechanical properties and cooling ability while maintaining or reducing weight levels, with high recyclability and serviceability also paramount in the design of the pack.
In today’s commercial EV batteries, fast charging rates can vary greatly depending on the battery’s state of charge (SOC), sometimes dropping significantly as SOC increases. During this test, Polestar saw charging speed rise from 310kW at 10 percent SOC to over 370kW at 80 percent SOC, proving the technology’s steady charging rate with no significant change in charging speed or efficiency whenever a driver decides to stop within this wide state-of-charge range.
Importantly, the test proves XFC technology works with today’s DC charging infrastructure, which continues to feature more high-power DC chargers of 350kW or higher.
This means drivers will be able to spend less time stopped to charge their vehicle, which for a 10 to 80 percent charge on many modern EVs could still take around 30 minutes. By reducing that time to 10 minutes, the charging time for a vehicle with XFC technology is much closer to what you would experience when filling a car with petrol. And thanks to the consistent charge speeds on offer, with a suitable charger, consumers could stop for five minutes at 50 percent SOC and continue their journey with over 80 percent SOC.
Dr Doron Myersdorf, CEO of StoreDot, comments, “We are very excited to share this impressive achievement today and proud to be on this journey with Polestar. Polestar’s commitment to acknowledge that extreme fast charging technology is necessary to make widespread electric car adoption a reality. This breakthrough revolutionises ownership by eradicating the barrier of range and charging anxiety once and for all as drivers will be able to travel long distances with the same freedom and convenience as traditional fossil fuel-powered vehicles.”
One issue that hasn’t been mentioned in this press release from Polestar and StoreDot is whether extreme fast charging technology will have an effect on predicted battery life. We have heard, on numerous occasions, that using a fast charger will shorten battery life. We’ve asked Polestar and StoreDot to comment.