Donut Lab Solid-State Battery and In-Wheel MotorsDonut Lab claimed to have made the world's first production-ready solid state battery. An in-depth investigation suggests otherwise.Donut Lab's battery has all the characteristics of an advanced lithium-ion battery, according to a new investigation.The Finnish startup could have been misled by a company called CT Coatings, which claimed to have the chops to build screen-printed solid-state cells. Finnish startup Donut Lab's claims of having developed the world's first production-ready all-solid-state battery are false, according to a new investigation by Ryan Hughes of the Ziroth YouTube channel. Donut Lab said its solid-state battery, which would power the electric Verge Motorcycles models, could charge in five minutes, last 100,000 cycles, deliver 400 watt-hours per kilogram of energy density, and remain immune to thermal runaway. The battery would also be completely free from rare earth materials, the company claimed. Typical lithium-ion batteries pack half the energy density and last a couple thousand cycles, so the startup's claims were bold, to say the least. AdvertisementAdvertisementBattery companies don't expect all-solid-state technology to be mass-produced until the end of the decade. That's exactly why the little-known startup's claims of having beaten them all to the punch sent shockwaves through the industry.Donut Lab Solid-State Battery and In-Wheel MotorsAfter months of skepticism from battery experts and efforts by Donut Lab to defend its technology, more conclusive evidence from the YouTuber now points firmly against those claims.Researchers believe solid-state cells to be the "holy grail" of battery technology. If successfully developed, they'd have little to no trade-offs. At least in theory, they promise to extend the driving range of electric vehicles and make fast-charging as quick as filling up gas. They'd also expand the battery's lifespan and make them fireproof. The reality, Hughes' investigation revealed, might be far more mundane. High-end lithium-ion cells have become so good that Donut Lab appears to have tried passing them off as solid-state ever since they debuted at CES this January.Hughes reviewed leaked internal emails, consulted battery scientists, and spoke with Lauri Peltola, the former chief commercial officer and co-founder of Donut Lab affiliate Nordic Nano. What emerged was a tangled web of companies chasing investor money, technology sourced from a separate firm called CT Coatings that turned out to be misleading, and Donut Lab's own failure—whether by choice or incompetence—to conduct the basic due diligence needed to verify what CT Coatings was actually delivering.AdvertisementAdvertisement"Neither of the companies had, when I was still working at Nordic Nano, a deep understanding on battery chemistry and manufacturing," Peltola told Ziroth. "I was relying on the information that I was receiving from Donut Lab, as was everybody on the Nordic Nano side." He added that before the reveal in January, Donut Lab told Nordic Nano that it had internally done thorough technical due diligence, and that they could "bravely" introduce the technology at CES. Among the most damning evidence is the lithium-ion cell's expansion curve, which is a way to graphically track the changes in the battery's thickness or internal pressure as it charges or discharges. Lithium-ion batteries with a standard graphite anode typically show a small but distinctive kink in their steep expansion curve at around 50-60% state of charge, caused by ions reordering themselves during charging and producing slight cell swelling, according to Hughes. Battery Expansion CurveDuring testing at Finland's VTT Research Institute, the Donut Lab cell showed an identical kink. The numbers didn't lie either. Ziroth said the cell's 94 watt-hour capacity, as revealed by the VTT test results, and the 315-gram mass that Donut Lab revealed at CES, work out to an energy density of 298 watt hours per kilogram, nearly identical to CT Coatings' own cell and well short of Donut Lab's claimed 400 Wh/kg.Several battery scientists InsideEVs interviewed after the initial announcement also urged caution and pushed for more substantiating data. The latest investigation highlighted that even impressive performance figures like charging the motorcycle from 10-80% in 12 minutes and surviving temperatures up to 100 degrees Celsius are well within the range of what advanced lithium-ion batteries can already achieve when stress tested.AdvertisementAdvertisementThat's the broader context worth keeping in mind. Lithium-ion battery technology has been moving fast. The new Mercedes-AMG GT can charge from 10-80% in just 11 minutes, thanks to silicon-containing anodes. Over in China, BYD's Flash chargers push its second-generation Blade batteries from 10-97% in just nine minutes. Verge MotorcyclesWhile genuine efforts to develop true solid-state batteries are underway at major companies like Toyota and CATL, firms with decades of manufacturing experience and billions in R&D budgets, it's likely a stretch to believe that the breakthrough would come from a startup that has never manufactured a single battery cell.Have a tip? Contact the author: suvrat.kothari@insideevs.comRelated StoriesWatch Donut Lab's Mysterious Solid-State Battery Charge In An Actual EVDonut Lab's Latest Solid-State Battery Test Proves It Isn't A SupercapacitorWhat Donut Lab's Latest Solid-State EV Battery Test Actually RevealsDonut Lab's Solid-State Battery Charges Fast. But Experts Still Have Questions
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