imagine an electric car that covers 752 miles on a single charge. you can't buy it today, but a modified tesla model s drove that distance across michigan last month. it was the work of a two-year-old michigan startup, our next energy (one), which says it is aiming to make safer and more sustainable batteries. one retrofitted the car with a battery holding twice the energy of tesla's original—while fitting entirely within the same space. it's a proof of concept for the company's own future battery design.
faster charging, or bigger batteries?
two ways exist to assuage range anxiety among ev buyers. the first is ubiquitous, reliable, nationwide dc fast charging, like tesla's supercharger network. unfortunately, only tesla offers that today. every other ev relies on a mishmash of private networks of varying reliabilities.
the second is to improve the range of evs by a combination of large-capacity batteries and improving their efficiency. that's the approach used by the mercedes-benz vision eqxx, an ultra-efficient concept ev that was just unveiled monday. its goal is to provide 620 miles of range in a luxury sedan.
one's project didn't mess with anything to alter the model s's efficiency, but employed a much higher-capacity battery. "we want to accelerate the adoption of evs by eliminating range anxiety, which holds back consumers today," said one founder and ceo mujeeb ijaz. he's a battery engineer with more than 30 years' experience, including stints at apple, a123 systems, ford, and others.
one put its higher-capacity prototype pack into a tesla model s long range plus, providing nearly 90 percent more range than its original 402-mile epa figure. the demonstration car is actually the same vehicle (before one modified it) that won our ev 1000 long-range trip last spring. in our own highway range test last may, that car achieved 320 miles at a steady 75 mph, the farthest distance we've recorded. (that model has since been supplanted by the model s long range, rated at 405 miles.)
the original tesla battery had a capacity of 103.9 kilowatt-hours, while the prototype one battery that replaced it in the same space has 207.3 kwh. ceo ijaz confirmed to c/d that one used "a single pack retrofitted in the same space as the original battery." so it's far more energy-dense, but delivered consumption (in miles per kwh) roughly equal to that of the original battery.
one's drive took place in mid-december in michigan—with chilly winter temperatures working against range maximization—where the company drove up and down the length of the mitten state for nearly 14 hours, averaging 55 mph, before winding up back at its novi headquarters in southeastern michigan with the trip odometer showing 752.2 miles. later, in a much less taxing test, the company put the model s on a dynamometer at a steady 55 mph, where it ran for a staggering 882 miles on a charge.
the company dubs its prototype a proof of concept. the point is to show that real-world ranges far longer than an average driver's endurance (pit stops, ahem) can be achieved in the near future. the next step is for it to evolve into a new battery called gemini, intended to go into production after 2023.
one says it focuses on battery chemistries that are "safer" and "sustainable," using a "conflict-free supply chain." in practice, that means lithium iron-phosphate (lfp) chemistry, which historically has energy density 30 percent lower than cobalt- or nickel-based chemistries (and, unfortunately, reportedly cold-weather issues). its first product, aries, will go into production late this year. it's a battery using prismatic lfp cells in a structural cell-to-pack architecture without separate modules, packing more cells into the pack to lower the energy disadvantage against cobalt cells.
one battery, two cell types
for gemini, the company plans to supplement the lower-cost lfp cells with a range-extender portion of the battery for extreme power needs, to reduce stress and deterioration in the bulk of the pack. range-extender cells will use an anode modified to eliminate graphite, which the company says "makes more volume available for the cathode" to boost the energy density of the range-extender cells.
the cathode will be made of a proprietary material rich in manganese that one says can be sustainably sourced at low cost. (the company has so far applied for 14 patents related to the gemini pack.) the lfp cells cover 99 percent of the vehicle’s duty cycle, ijaz told c/d, and the range extender is used for just 1 percent.
as a proof of concept, however, the prototype pack used in the demonstration was powered by different cells. the capacity of more than 200 kilowatt-hours was provided by high-energy cobalt-nickel cells, while those intended for the gemini line are still under development.
the point of this test, then, wasn’t about one's future plans for new cells. instead, it was to show that it's possible to pack considerably more energy into a battery the same size as today's—without, for instance, double-stacking a pair of packs, as gm is doing in its 2022 gmc hummer ev.
headlines about evs with 752 miles of range, or the eqxx's target of 620 miles, or the 520 miles of the 2022 lucid air version now being delivered, should go a long way to reassure nervous buyers. people will start to believe that evs capable of very long ranges are possible—even if they end up opting for a more affordable 300-mile alternative in the end.