Introducing the 36-Million-Mile 'Century Battery' for EVsWelcome...

Introducing the 36-Million-Mile 'Century Battery' for EVsWelcome back to The Electric! You’ve probably heard of the million-mile battery, the effort by automobile companies such as Tesla and General Motors to put electric vehicles with extremely long life on the road. In this week's edition, the inventor of the million-mile battery ups his game with a surprising new concept. Correction: In the flash analysis on Tuesday, I incorrectly wrote that no silicon anode companies have formed partnerships with automakers. At least two of them have—Sila Nanotechnologies, backed by Mercedes-Benz and BMW, and Solid Power, which has partnerships with Ford and BMW. Thanks to Sila CEO Gene Berdichevsky for emailing me about this.Jeff Dahn's new brainchild is the "century battery." Photo: Courtesy Dalhousie UniversityThree years ago, Jeff Dahn, one of the world’s most respected battery scientists, attracted unusual attention—and some bewilderment—with a claim that he and other researchers had developed a battery that would power an electric vehicle for a million miles. Some of those scratching their heads wondered—even if Dahn’s battery worked as he said—how big the market was for a vehicle that could last a million miles. Wouldn’t the vehicle itself disintegrate by then? The idea caught the imagination of some in the industry, though: In 2019, Tesla CEO Elon Musk said he would introduce an EV with a million-mile battery the subsequent year. Musk missed his self-set deadline, but General Motors claims its electric Cadillac Lyriq, to come out later this year, will contain a million-mile battery.Now Dahn, a physics professor at Canada’s Dalhousie University and a battery adviser to Tesla, has a new claim: a 36-million-mile battery. If his numbers are right, the battery would last about 100 years, and hence he has dubbed it the “century battery.” No one is known to have made anything close to a century EV battery before, and in disclosing his lab results at an industry conference last week in Orlando, Fla., Dahn invited the obvious question: If barely anyone needs a million-mile battery, what’s the demand for a battery that lasts 36 times as long?For Dahn, the motivation is almost theological: He, like most battery scientists I meet, is driven by a hope that batteries will help save the planet from the worst ravages of climate change. He believes the century battery could be used both in cars and on the grid, where it could reduce the need to burn coal and natural gas, becoming a crucial piece of the climate change arsenal. Yet I became compelled by a different case for centenarian batteries: They address probably the most important long-term economic problem in EV batteries—the critical shortage of metals and minerals. If most of your EV batteries last decades, you will need to make far fewer of them over time and to mine much less critical minerals. So don’t be surprised if you see a lot of such technology emerging in the years to come.Dahn’s work is at odds with the push for more-powerful batteries. Automobile buyers have made clear that they want EVs that can go a long distance and charge up fast when they run out of electricity. Such EVs are powered by batteries with expensive metals that are subjected to onerous stresses that cause them to degrade. People like Dahn say the range enthusiasts have gone too far; Dahn, for instance, designs his batteries with just 250 miles of range, which requires smaller quantities of costly metals like nickel. But American and European drivers don’t care about all that—they want the long range: In a survey released in January by Deloitte, for instance, Americans on average wanted an EV to go 518 miles on a charge before they would consider buying one. Europeans wanted 383 miles—fewer, but still a lot compared with the 234 miles of average range in new EVs last year. Only Chinese drivers more or less accepted today’s reality—they said 258 miles would be sufficient.This isn’t a surprise. Americans also buy houses more spacious than they need and meals larger than they ought to consume. (How many Americans would walk into Burger King and order the “teeny meal?”) But when it comes to EVs, long range means batteries stuffed with some 700 pounds of metals, minerals and other materials. And when you add up the metals needed for the future EV fleet, the numbers start to get really, really large. For instance, if Tesla sells 1.4 million EVs this year, which a number of analysts expect, the company will require 476,000 tons of nickel, cobalt, lithium, graphite, manganese, iron, copper and other materials, according to data provided by Benchmark Minerals Intelligence, a research firm. Add the materials necessary for the 5.5 million EVs forecast to be sold in China this year, and the smattering from GM, Ford, Volkswagen and so on, and you reach a truly gargantuan tonnage of ore—just for this year. By 2030, automakers are aiming to sell 40 million EVs a year, which, measuring based on today’s technology, would require 14 million tons of battery metals and other materials. To meet the demand, Wood Mackenzie, an energy research firm, estimates the world will need 20 new lithium mines the size of the current largest (Greenbushes in Australia), 10 new cobalt mines the size of the world’s largest (Mutanda in the Democratic Republic of the Congo) and 22 nickel mines the size of one of the world’s largest (Ambatovy in Madagascar). A few new mines will open over the coming decade, but there won’t be sufficient supplies of key metals. “Even in the most optimistic scenarios, where every single raw material project in the pipeline comes on stream and existing operations expand aggressively, there will not be enough raw material for the battery supply chain as we go into 2030,” Benchmark wrote in a March 31 report.Against the backdrop of this reality, President Joe Biden last week invoked the wartime Defense Production Act in an effort to speed up U.S. production of battery materials. But the move was mostly symbolic, since it included no action to streamline the lengthy process of mine permitting: Mining companies say it routinely takes up to 10 years to get from mine conception to ore production in the U.S., meaning that even if a company applies today to dig for nickel, it probably will not produce any ore until 2030 or 2032. Through this decade and probably the next, the U.S. and Europe—the whole world, apart from China—are poised to be painfully short of battery metals.Which brings us back to the centenarian battery. Dahn’s contention is that century batteries are necessary if the U.S. and the rest of the West are to have sufficient metals for the planned production of EVs, while also resolving climate change. Only, to get there, the long-range advocates will have to moderate their demands.A New EV BattleThere actually is at least one other century battery on the planet. It’s what’s known as a dry pile battery, and it has been ringing two electric brass bells constantly at Oxford University in England since 1840—more than 10 billion rings in total. It’s not known how exactly the battery works, since without taking it apart no one can determine what mechanism it uses, but it is certain that powering the brass bells is a wholly different proposition from running an EV. EV batteries must simultaneously supply both range and acceleration, capabilities whose physics are at odds. They must also be safe, inexpensive and fast charging. Thomas Edison’s nickel iron battery, introduced in his EVs in 1901, could last decades, but it would not stand up to the demands of today’s EVs in terms of weight and range.Dahn is the co-inventor of the nickel-manganese-cobalt cathode, the most prevalent commercial EV cathode in use today. His other claim to fame is his no-nonsense attitude—in a field replete with exaggeration and no small bit of outright fibbing, Dahn is renowned for calling out the lack of data in colleagues’ claims, both publicly and to their faces. His own approach involves the meticulous cataloging of measurements for what other researchers think has already been adequately measured. And that is the origin of his million-mile and century batteries.It all goes back to a 2019 paper that Dahn co-authored in which he explained how to design a battery that would barely degrade. In what Dahn said he meant almost as an aside in the abstract, he wrote that the battery could last a million miles. When reporters (including me) saw this, our eyes got wide, and we dubbed his invention the “million-mile battery.” But how did he get there when everyone else was fighting to get to 150,000 miles? Dahn said he used high-quality artificial graphite in the anode and applied extra care in devising his electrolyte, the liquid that lies between the electrodes and facilitates the movement of lithium ions. But the key step, Dahn said, was to change the battery’s fundamental structure. He started with a formulation of NMC known as NMC532, containing half nickel and 30% manganese, which he knew from experience performed well under EV conditions. But rather than relying on the usual polycrystalline particles, he used NMC made of larger, single crystals. This addressed a typical problem that ages today’s batteries—when you shuttle the lithium back and forth between the electrodes during the charge and discharge cycle, the cathode particles tend to eventually fracture. This problem all but vanishes if you use single crystals, Dahn claimed in his paper. Some critics griped that the single-crystal process cost too much to be practical, but Dahn told me that the price from Chinese suppliers is now just 1% higher than for polycrystalline particles.Since then, Dahn has kept the cell cycling. In his keynote address at last week’s International Battery Seminar, a major annual industry conference, Dahn said he had gone into his lab to check the cell just before getting on the plane. It had reached almost 15,000 cycles and retained an astonishing 95% of its original capacity. If you are achieving 250 miles to a cycle, the distance for which Dahn designs the batteries, his famous cell was now a 3.7-million-mile battery and was more or less still in brand-new condition.As Dahn and his research group continued to work on lifetime questions, they focused on both NMC and lithium-iron-phosphate cathodes. Most in the industry today consider LFP the longest-lasting cathode. But Dahn’s team kept finding that NMC outperformed LFP in terms of lifetime, especially when they changed the type of electrolyte salt they employed. They decided to check what would happen if they ran an experiment using single-crystal NMC532, a high-quality artificial graphite and the new electrolyte salt, and charged the battery to 3.8 volts, just a tad higher than the 3.65 volts at which LFP runs. They cycled the cell continuously at room temperature, and then projected its lifetime. “You can see it’s crazy,” he said. “At 27 degrees [Celsius], the projection is 100 years.”As for LFP, it lasted roughly 15 years in Dahn’s experiments. That surprised me because Chinese company BYD has touted its Blade battery, which runs on LFP, as having 750,000 miles of life. I had been viewing the Blade as a five-decade battery, as that’s what you get when you divide the total by 13,000, the number of miles driven annually by the average motorist. But Dahn said the 750,000 miles is valid only if you drive that much within 15 years. After that, the materials themselves wear out. This is known as the battery’s “calendar life.” The scenario is similar with the GM Ultium battery, which the automaker is touting as its million-mile battery. Technically, it can go 1 million miles, but again, that works only if you drive those miles within a certain number of years. Dahn wasn’t sure how long the Ultium’s calendar life is, since he hasn’t studied it. But it’s not seven decades, although that is what you would get if you did the plain division. Dahn said that unlike these batteries, his appears to be an authentic century battery—according to the experimental findings, its calendar life is at least 100 years (and in ordinary driving, 2,769 years).In a world in which smartphone and laptop batteries start fading after a year or two, and most EV batteries are guaranteed for just eight years, Dahn’s results boggle the mind. It is also fitting that yet again Dahn has emerged with a contrarian technology while the rest of the field pursues range by adding silicon to the anode and attempting to scale up a lithium-metal anode. His battery only gets 250 miles because he is running it relatively mildly: He is not pushing up the voltage, which can give a battery longer range but also stresses and degrades it. He is using a relatively low content of nickel—the current standard is 80%, 90% or even more, which again produces greater range. And he is not adding silicon to the anode—silicon is prized for the added energy it supplies, but it also expands four-fold during cycling and can fracture the battery. But if your objectives are extreme long life, reducing the demand for metals and not using the colossal amounts of fossil fuel energy that mines require, long range is less important. This does not mean that the project is finished: Next, Dahn’s team will try bumping up the voltage to as much as 4.1 to see whether that will extend the range without hurting the lifetime too much. If they can get the number closer to 300 miles, that should go a long way toward pacifying unhappiness over insufficient driving distance. Dahn has another aim for his long-lifetime batteries: enabling a technology known as vehicle-to-grid, which pays motorists to allow their EV batteries to buttress power stations. If motorists are using an ordinary battery that lasts only a decade or so, they are unlikely to allow their local utility to degrade it with use. But if they have a century battery, why not? They can drive and hook up to the grid with abandon. When they sell the car, potential buyers will know the battery is still good. And when the vehicle is ready for the junkyard, the battery can go for a second life on the grid or be recycled for its metals. “We need more solar and wind and we need more energy storage. But look where all the batteries are—they’re in the cars,” Dahn said. “So we need to access all the storage capacity in vehicles when they’re parked. We need vehicle-to-grid. It’s as simple as that.”“It’s sort of orthogonal to the way everyone is going—higher energy density, more silicon, higher energy density, more silicon,” he said. “You would think this is going backward. But lifetime is incredibly important.”