General Motors brings 33% denser lithium manganese-rich EV battery tech to Tennessee

The race to build cheaper, longer-range electric cars has taken a leap forward in central Tennessee. Ultium Cells has announced that it will produce lithium manganese-rich (LMR) prismatic battery cells at its plant near Nashville.

The company is a joint venture between General Motors and South Korea’s LG Energy Solution. Once operational, the facility is expected to become the world’s first commercial manufacturing site for this next-generation battery design.

Upgrades to the Spring Hill plant will start later this year. Engineers expect to finish construction by 2028.

Automakers have long struggled to balance battery price against driving range. Today, the global market relies heavily on two main chemistries: premium high-nickel packs that offer maximum range at a steep cost, and low-cost lithium iron phosphate (LFP) cells that sacrifice range to keep prices down.

Offers greater energy density

LMR prismatic cells are engineered to disrupt that equation. The new chemistry provides 33% greater energy density than standard LFP cells, yet it can be produced at roughly the same price point.

For General Motors, integrating this technology provides an intermediate tier. High-nickel batteries will remain the benchmark for premium vehicles requiring maximum endurance. However, LMR cells will allow entry-level and mid-tier models to gain substantial driving range without inflated sticker prices.

“High-nickel batteries will continue to give customers the highest range in our portfolio, while adding LMR positions us to leapfrog today’s more affordable chemistries and deliver lower costs with better performance,” said GM in a press release.

Company executives note that this flexibility will help GM scale vehicle production more efficiently, broaden customer reach, and improve profit margins.

Addressing the main bottleneck

The decision to scale up manufacturing follows a major scientific hurdle cleared just weeks ago.

While LMR chemistry has held promise for years, it has suffered from a critical design flaw: gas buildup. In large electric vehicle packs, trapped gases create severe internal pressure. This swelling warps the battery’s internal structure and accelerates degradation, making large-format cells unsafe and short-lived.

In September, researchers from LG Energy Solution and Seoul National University published a practical solution. The team discovered that gas formation is driven by volatile oxygen reactions during charge cycles.

By fine-tuning the operational voltage window, the researchers stabilized how oxygen moves inside the cell. The results were striking. In laboratory evaluations, optimized 40 Ah-class cells maintained 92.2% of their original energy capacity after 883 charge and discharge cycles—a durability threshold suitable for automotive use.

Tailoring specific packs

Beyond the chemistry itself, the Spring Hill project signals a broader change in how modern battery plants operate.

The expansion gives Ultium Cells the ability to manufacture multiple cell chemistries and geometric form factors on the same campus. This enables the joint venture to tailor specific packs to distinct vehicle types, from heavy pickup trucks to compact city cars.

“Beyond flexing manufacturing might, bringing this new battery cell to market first is a milestone moment for keeping America competitive globally in EV and battery technology leadership,” concluded GM.