Lithium iron phosphate (LFP) batteries were a made-in-America innovation, but China ended up cornering the market on what became the world’s leading solution in low-cost EV batteries. Now, following a decade of development, General Motors has announced a battery breakthrough that might help American manufacturers reclaim some high ground: LMR, or lithium manganese-rich batteries.
Kushal Narayanaswamy, GM director of advanced battery cell engineering, says the company’s LMR batteries can deliver 33 percent higher energy density than China’s best LFP cells, at comparable production costs. That potentially opens the door to the more-affordable EVs that consumers want, without unduly sacrificing driving range.
“We’ve decided to industrialize this technology for our full-size trucks and SUVs” beginning in 2028, Narayanaswamy says.
That plan could make GM the world’s first automaker to deploy LMR batteries in an EV. GM has built a growing EV business via conventional nickel-rich “Ultium” batteries — enough to pass Tesla as the largest U.S. producer of battery cells. Those pouch-style Ultium cells, built with partner LG Energy Solution in huge factories in Ohio and Tennessee, deliver up to 792 kilometers (492 miles) of range in GM’s Chevrolet Silverado. That range, verified by the U.S. Environmental Protection Agency, is tops among any full-size electric pickup truck.
High Battery Costs Drive Skyrocketing Car Prices
But aside from a basic work-oriented version, that Silverado starts at around US $75,000, and tops $90,000 for lavish versions. The Cadillac Escalade IQ I recently tested in metro Detroit — essentially a luxury condo on wheels — is another long-ranger, stretching past 740 km (460 miles) on a charge. Caddy’s three-row SUV is also expensive, starting at nearly $130,000.
Those prices trace directly to high costs for cobalt and nickel in today’s most energy-dense cells. Such burdensome costs helped spark an LFP revolution, which jump-started the explosive growth of EVs in China, including budget models with limited range. Ford is racing to build a controversial LFP plant in rural Michigan, and Stellantis is doing the same in Spain, with both automakers licensing LFP technology from China’s CATL.
LFP batteries replace pricey cobalt and nickel with plentiful, inexpensive iron and phosphate, and they are notably safe and durable. The tradeoff for all that is mediocre energy density. For example, the latest “Blade” LFP battery from Chinese automaker BYD delivers just 350 watt-hours or so per liter of volume, versus more than 600 watt-hours per liter for GM’s Ultium batteries, or Tesla’s 4680 cells.
GM has found a middle ground with manganese, a transition metal that could help automakers blunt China’s current near-monopoly on LFP production.
“Manganese is dirt cheap, so at a raw materials level, it gives you that benefit to start with,” Narayanaswamy says.
Compared with Ultium cells — whose chemical composition is roughly 85 percent nickel, 10 percent manganese and five percent cobalt — the LMR cells contain about 65 percent manganese, 35 percent nickel, and only trace amounts of cobalt. And for GM, LMR is a home-grown technology: theWallace Battery Cell Innovation Center, located at GM’s Eero Saarinen-designed tech campus in suburban Detroit, has become a linchpin of development.
The result is a battery that should cut costs without throttling range, delivering more than 650 km of range in a full-size electric truck or SUV. That’s enough to satisfy road-tripping consumers or owners who haul heavy payloads. One GM executive estimated an LMR pack could cost $6,000 less to produce than today’s batteries.
A full size lithium manganese-rich battery cell is about the size of a coffee-table book.Steve Fecht/General Motors
The manganese-rich cathode chemistry also lends itself to large-format rectangular cells that make for efficient packaging in larger trucks and SUVs. For prismatic cells roughly the size of a coffee table book, a higher percentage of active battery material can reduce the number of components in individual battery modules by 75 percent, and total pack components by 50 percent, while still providing the necessary structural rigidity. For example, a Silverado EV or Escalade IQ could replace their double-stacked pack of 24 NCMA (nickel, cobalt, manganese, aluminum) modules with just six LMR modules. More active battery material would partially offset a reduced energy density versus high-nickel cells. And that would translate to more miles-per-dollar for buyers.
By the end of last year, Narayanaswamy says, the Wallace Center had produced about one ton of LMR cathode material, allowing it to build 300 prototype cells in 18 varieties. Those cells were tested to the equivalent of 1.4 million miles of real-world EV driving, including vibration testing and extreme swings in ambient temperatures. Being able to create production-feasible cells in-house meant that GM didn’t need to engage potential suppliers in advance, or waste time on back-and-forth validation and duplicated efforts.
Vertical Integration Means Faster Development and Lower Costs
That’s the kind of vertical integration that Chinese automakers such as BYD — which designs and builds its own cars, batteries and chargers — have leveraged to speed new cars and batteries to market and build them at unbeatably low costs. Narayanaswamy says the Wallace Center’s goals include taking cell designs from the drawing board to production readiness in as little as 18 months.
GM’s internal testing reassured engineers they had overcome longstanding barriers to LMR cells, mainly unreliable lifespan and “voltage attenuation,” with cells losing excessive voltage over time. GM cites proprietary dopants and coatings, particle engineering and process innovations, all aiming to balance energy-density requirements with cell stability. For coatings, “it could be aluminum or tungsten or boron that helps prevent the contact of manganese with the electrolyte itself,” he says.
Narayanaswamy is confident the LMR cells will match the lifespan of GM’s current NCMA batteries, which offer an eight-year, 100,000-mile warranty. Critically, GM can manufacture its prismatic LMR cells in existing battery plants, allowing domestic production without building new lines from scratch.
“In fact, the processing steps for making LMR actually get reduced by a couple of steps,” he says.
At the Wallace Center, GM continues to work on a range of potential battery solutions, including silicon anodes, lithium-metal, sodium-ion, and in the longer-term, solid state. LFP remains part of its technology roadmap as well. The automaker plans to open another Detroit-area lab by 2027, the Battery Cell Development Center, that can build and test complete battery packs before they enter production — no matter what kind of chemistry ends up inside.
From Your Site Articles
Related Articles Around the Web