General Motors on Tuesday said it’s planning to become the world’s first automaker to use lithium-manganese-rich (LMR) batteries in production trucks and full-size SUVs starting in 2028. The new chemistry marks a major pivot, not just from today’s nickel-manganese-cobalt (NMC) and lithium-iron-phosphate (LFP) batteries, but also from pouch cells GM has long relied on.

Going forward, some of GM’s EVs will use LMR cells in a prismatic format. Models using LFP and NMC aren’t going anywhere. The three battery types will continue to co-exist, offering buyers a breadth of options depending on their needs.

What’s The Big Deal With Prismatic LMR Cells?

General Motors LMR Prismatic Cell

Photo by: General Motors

GM says the LMR chemistry is close to LFP when it comes to the cost advantages and closer to NMC in terms of performance and energy density. The LMR chemistry is closely related to NMC, but uses far lower content of the expensive and dirty metals nickel and cobalt, and instead employs a much higher portion of manganese, which GM says is relatively inexpensive and abundant in Earth’s crust.

But it’s not just the chemistry GM is rethinking. The shift to prismatic cells is just as important.

In the battery world, shapes and sizes matter. Prismatic cells are basically square-ish or rectangular, giving them a modular and stackable design that’s easier to integrate into battery packs. In simple terms, a better fit equals less wasted space inside a pack and an overall space-optimized battery design. GM’s pouch cells also fit neatly together, but large format prismatic cells have more advantages.

“Our pouch cells today have a left and a right module which are really hard to connect into one larger module,” Andy Oury, a battery engineer and business planning manager at GM told reporters in a briefing at the automaker’s R&D center in Warren, Michigan last week.

“Fewer larger modules is a cost reduction strategy and having that particular prismatic cell shape is really important to the overall simplification of the module and production,” Oury added.

Development of LMR batteries didn’t happen overnight. GM has been working on it for a decade, but the pandemic kicked things into high gear. The company began in-house materials R&D in 2020, built a demo cathode in 2021 and produced its first full-size batch of LMR cells in 2023. By 2024, it had manufactured over a ton of LMR cathode active material (CAM) and locked in a vehicle application early this year.

About a year and a half ago, the automaker also roped in Kurt Kelty, a battery industry veteran who spent 15 years at Tesla and then joined GM as its new head of battery and propulsion. And he wasn’t immediately sold on the prismatic cell format. GM engineers had to convince their new boss.

“I came in with a bias. I was like of course the answer is cylindrical. It has to be cylindrical,” Kelty said. “But my team pointed out the differences, how we can get a higher energy density at a lower cost,” he added.

Now GM says the prismatic cell format alone is enabling 75% fewer parts than its pouch cells on the module level and 50% fewer parts on the overall pack level. “Hundreds of pounds” of weight savings are expected, too. GM engineers said prismatic LMR cells promise 33% more energy density and costs that are “comparable” in dollars per kilowatt hour compared to LFP batteries.

LFP battery tech is rapidly improving in China, but the country also enjoys a stranglehold on that supply chain. The U.S. needs its own playbook, one that’s tailored to unique American challenges, like making full-size electric trucks and SUVs actually make sense economically.

Currently they don’t exactly do that. I saw the Hummer EV’s 24-module battery pack at the General Motors Technical Center in Michigan last week and it looked about the size of a king-size mattress and the weight of an entire BYD Seagull, nearly 3,000 pounds.

Will It Work? Too Early To Tell

GM Wallace Battery Innovation Center Michigan

Photo by: Suvrat Kothari

Prismatic LMR cells are still far off from mass production. We’re at least three years away from seeing it in a production vehicle. But GM is betting on it and so is Ford.

“The Model 3 and Model Y were developed years ago, and to change them at this point is a huge deal,” Kelty said, referring to why the mass market Teslas have remained largely unchanged in terms of their battery chemistry over the years.

But after several production delays and software headaches in the recent past, GM finally seems to have found a way to cut through its bureaucratic red tape, giving its battery teams the rare, startup-like freedom to innovate and solve problems fast.

“If you’re starting with a blank sheet of paper, you can use anything you want, you can use cylindrical, prismatic, pouch and any chemistry,” Kelty said. “That’s a win for a battery guy. It doesn’t get much better than that.”

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