Tesla lead battery researcher Jeff Dahn and members of the Department of Physics and Atmospheric Science in Dalhousie University recently released a new paper that points to the development of battery cells capable of lasting over 1 million miles on the road, or 20 years if utilized in grid energy storage.

“We conclude that cells of this type should be able to power an electric vehicle for over 1.6 million kilometers (1 million miles) and last at least two decades in grid energy storage,” the team noted in their paper.

It should be noted that the cells utilized by the researchers are pouch cells as opposed to the cylindrical cells favored by Tesla for its electric vehicles. The new cells feature new chemistry, which improves energy, charge rate and more importantly, allows a larger SOC swing. These optimizations result in savings, both in weight and in cost.

3/ Second life of these packs will change the nature of the grid in the future. As a former battery exec this data is very, very impressive. Thanks @BrianTHeligman for pointing me to the paper! And huge kudos to Jeff and the Dallhausie team for pulling this off. — Ric Fulop 🚀 (@ricfulop) September 8, 2019

The idea of a million-mile battery has been mentioned by CEO Elon Musk in the past, together with the development of a drive unit that is also capable of lasting for a million miles on the road. With such innovations in place, Tesla’s battery cells, which are already among the best in the industry, are bound to last even longer.

Used in electric vehicles and operated at temperatures controlled to 20C, the new battery cells are expected to retain 95% fractional capacity after the million-mile mark is reached. Battery cells used for energy storage, on the other hand, are expected to retain 90% fractional capacity after over 20 years of service. Commenting on Dahn’s research, Desktop Metal CEO Ric Fulop stated that the second life of these improved battery packs have the potential to change the very nature of the grid in the future.

These improvements are pretty much the perfect match for some of Tesla’s upcoming projects, particularly its all-electric truck, the Semi. The Semi was announced with a range of either 300 or 500 miles, though Elon Musk has previously hinted that the vehicle will have closer to 600 miles of range per charge instead. The vehicle has garnered warm reception from several large corporations, from UPS to PepsiCo. As such, it is certain that once the Semi gets deployed, the vehicle will be on the road constantly, putting much strain on the truck’s batteries. Having batteries that last longer will make the vehicle more attractive to potential buyers.

This chart usefully summarises the report’s findings with respect to longevity.



With operating temperature controlled to 20C :



– Vehicle Battery lifetime can exceed 1,000,000 miles before reaching 95% Fractional Capacity (blue line) pic.twitter.com/PlqDSiowJE — JPR007 (@jpr007) September 9, 2019

This is where the improvements highlighted by Dahn’s team come in. With longer-lasting batteries, the Tesla Semi could stand toe-to-toe with its diesel-powered counterparts, which typically require an engine overhaul at around the 700k to 1 million-mile mark. Together with a drivetrain that also lasts a million miles and an overall cheaper operating cost, the Tesla Semi could prove to be a competitive alternative to the tried-and-tested diesel rigs of the trucking industry.

It should be noted that Tesla’s current battery tech is likely far ahead of the cells described by Dahn and his team in their paper. Sharing such data, after all, suggests that Tesla has already developed, or at least, is working on an improved version that would allow them to have an even more considerable advantage in the battery segment. This, of course, could widen the gap between Tesla and its competitors in the electric car industry even further.

Jeff Dahn and the Dalhousie University team’s 1-million-mile battery paper could be accessed below.

J. Electrochem. Soc. 2019 Harlow A3031 44 by Simon Alvarez on Scribd