An electric vehicle battery has to balance three demands that rarely improve together: cost, size and driving range. General Motors and LG Energy Solution have now made a sizeable manufacturing bet on a chemistry they say could shift that balance.
On 29 September 2026, their Ultium Cells joint venture announced plans to retool its Spring Hill, Tennessee, plant to make lithium manganese rich, or LMR, prismatic battery cells for future GM vehicles. Tennessee’s economic development department puts the additional investment at US$1 billion. Facility work is due to begin later in 2026 and finish in 2028, with 500 new jobs projected. This is a factory investment and production plan; the companies have not announced that commercial LMR cells are coming off the line today. GM announcement · Tennessee government announcement
What changes inside the battery?
LMR describes the material on a lithium-ion cell’s positive electrode, or cathode. The manganese-rich formulation is intended to store more energy at a cost that can compete with lithium iron phosphate, known as LFP. “Prismatic” describes the cell’s rectangular shape. It helps manufacturers package cells into a battery pack; it does not by itself establish better battery chemistry.
GM says its planned LMR cells are designed for 33% higher energy density than LFP at a comparable cost. Energy density means how much energy a battery holds for its size or weight. That is a company design claim for cells, not a measured promise that a finished vehicle will travel 33% farther. Vehicle range also depends on pack design, weight, efficiency and driving conditions. GM says it will continue using high-nickel cells where it wants the longest range, while adding LMR for other needs. GM’s description of the technology and portfolio
The step that matters is mass production
Battery chemistry can look attractive in development and become harder to manage across thousands of large cells made to tight tolerances. The announcement does not include independently verified production yields, long-term durability data for these future commercial cells, vehicle range figures or a confirmed date when finished batteries will ship in cars.
Reuters reported that the Tennessee plant is expected to be upgraded through 2028 and that the companies did not specify when cell production will begin. GM’s earlier aim was to start US commercial LMR production in 2028. That remains a target until the line is running and its output is qualified for vehicles. Reuters, 29 September 2026
The investment matters because it moves LMR from a promising battery option towards an actual manufacturing commitment. Whether it changes the cost and range of future EVs will depend on the evidence still to come: production at scale, cell life, pack performance and vehicles customers can buy.
Featured image: representative photograph by Lenny Kuhne / Unsplash. The photographs do not show the specific Tennessee facility or LMR battery cells described.
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