GM and LG Energy to Retool Tennessee Battery Plant for Lower-Cost LMR Cells

General Motors and LG Energy Solution plan to start upgrading their Ultium Cells battery plant in Spring Hill, Tennessee, later in 2026 to manufacture lithium manganese-rich prismatic cells for future GM electric vehicles, Reuters reported Tuesday, citing the companies. Construction and equipment upgrades are expected to be completed in 2028, although the companies did not disclose when cell production will begin.

The move gives GM a U.S. manufacturing home for a battery chemistry it has spent years developing as a lower-cost alternative for large electric vehicles. Reuters also reported that the expansion is projected to create 500 jobs. The Spring Hill facility is already operating after another recent change in product mix, making lithium iron phosphate cells for stationary energy-storage systems rather than relying only on the high-nickel pouch cells around which the plant was originally built.

That makes the latest plan more than a simple capacity addition. Spring Hill is becoming a flexible battery site that can be repurposed as GM and LG Energy Solution adjust chemistry, form factor and end market. The plant was launched through the companies’ Ultium Cells joint venture after a $2.3 billion investment announced in 2021.

Spring Hill is changing its battery mix again

Ultium Cells said in March that Spring Hill was being retooled to make LG Energy Solution’s JF2 lithium iron phosphate, or LFP, pouch cells for energy-storage systems, supported by a $70 million process investment. The company said at the time that 700 employees who had been furloughed in January were returning as the new line came online. Ultium described the Tennessee factory as a platform capable of supporting multiple cell chemistries.

That energy-storage shift followed an earlier plan to make LFP cells for GM electric vehicles at Spring Hill. In July 2025, GM said it expected the plant to begin converting lines for automotive LFP production, with commercial output targeted for late 2027. By March 2026, however, Ultium Cells was instead directing Spring Hill LFP production toward stationary storage, where demand from grid projects and data centers had become an important outlet for U.S. battery capacity.

The latest LMR plan points the EV side of the site in a different direction. Reuters reported that the Tennessee plant currently makes LFP cells for energy storage and that the new upgrade will prepare it for prismatic LMR cells. Unlike pouch cells, prismatic cells use a rigid rectangular enclosure. GM has said the format can simplify battery packs by reducing the number of modules and mechanical parts.

The transition also shows how quickly U.S. battery manufacturing strategies are changing. Automakers spent the first half of the decade building large domestic cell plants around projections for rapid EV growth. Slower demand growth and changing product plans have since pushed manufacturers to use some capacity for stationary storage, while continuing to develop cheaper EV chemistries that could make larger electric vehicles more economical.

Why GM is putting more weight on LMR

GM and LG Energy Solution announced their LMR commercialization program in May 2025. The companies said Ultium Cells planned to begin commercial production of LMR prismatic cells in the United States in 2028, with pre-production expected at an LG Energy Solution facility by late 2027. GM’s official LMR announcement said the chemistry is intended for future electric trucks and full-size SUVs.

The cost case rests partly on the cathode. LMR cells use a higher share of manganese and less of expensive materials such as cobalt. GM and LG Energy Solution say their design can deliver 33% higher energy density than their best-performing LFP cells at a comparable cost. GM also says pairing LMR chemistry with prismatic packaging could support electric trucks with more than 400 miles of range while reducing battery-pack cost compared with today’s high-nickel packs.

That positioning is important for pickups and large SUVs because battery size has a direct effect on vehicle cost and weight. LFP is widely used as a lower-cost chemistry, but its lower energy density can require more cells for the same range. GM’s LMR strategy is an attempt to keep much of the cost advantage while storing more energy in a given package.

Commercializing manganese-rich cells has not been straightforward. GM has said it began researching manganese-rich lithium-ion cells in 2015 and accelerated prototype work in 2020. Historically, LMR chemistries have faced durability and voltage-decay problems. LG Energy Solution said earlier this month that joint research with Seoul National University improved stability in large-format LMR cells by adjusting charging, discharging and formation conditions; optimized 40 Ah cells retained 92.2% of their initial energy after 883 cycles in the company’s reported tests.

The new Tennessee manufacturing plan therefore sits at the end of a long development chain rather than representing a sudden chemistry switch. GM has already been validating full-size LMR prototypes at its battery development facilities, while LG Energy Solution brings its own prismatic-cell manufacturing experience and a large patent portfolio in the technology.

The 2028 timetable now has a specific U.S. plant

Until now, GM and LG Energy Solution had publicly targeted U.S. commercial LMR production in 2028 without naming the final Ultium Cells location. GM said in July 2025 that Spring Hill would handle LFP while a home for LMR still had to be finalized. The decision to prepare Spring Hill for LMR gives that earlier national production target a specific manufacturing site.

The companies still have several milestones to clear. Reuters reported that construction and upgrades are expected to finish in 2028, but that no start date for LMR cell production was disclosed. GM’s earlier schedule called for pre-production at an LG Energy Solution facility by late 2027 and commercial U.S. production in 2028, so completion of the Tennessee conversion will need to line up with validation of the final production design.

Spring Hill’s role may continue to span more than one market. Its LFP line is already serving stationary storage, while the planned LMR equipment is aimed at GM vehicles. That mix gives Ultium Cells a way to use the same large manufacturing campus across different demand pools instead of tying the site to one chemistry or one application.

For GM, the practical test comes in 2028. The automaker has said LMR is central to lowering the cost of long-range electric trucks and SUVs, and Spring Hill is now the plant expected to make that strategy manufacturable at scale. Until production timing is disclosed, the completion of the Tennessee upgrade remains the next concrete milestone.