General Motors and LG Energy Solution are taking the next step toward commercializing lithium manganese-rich (LMR) battery technology for future electric vehicles. Through their Ultium Cells joint venture, the companies plan to upgrade the Spring Hill, Tennessee battery facility to produce large-format LMR prismatic cells.
The technology is particularly important because GM says its LMR cells have the potential to deliver 33% higher energy density than LFP cells at comparable cost. If the technology reaches production targets, it could give GM another battery chemistry between low-cost LFP and higher-energy-density nickel-rich batteries.
However, the headline 33% figure should not be interpreted as a guaranteed 33% increase in vehicle range. It is a company-stated cell-level energy-density comparison, while final vehicle range will depend on battery-pack design, vehicle efficiency, usable energy, weight and other engineering factors.
GM LMR EV Battery: Quick Facts
| Technology | Lithium Manganese-Rich (LMR) |
| Cell format | Prismatic |
| Compared with | Lithium Iron Phosphate (LFP) |
| GM-stated energy-density potential | Up to 33% higher than LFP |
| Production location | Spring Hill, Tennessee, USA |
| Facility upgrades | Beginning later in 2026 |
| Target completion | 2028 |
| Target applications | Future GM electric trucks and full-size SUVs |
What GM and LG Energy Solution Announced
Ultium Cells, the battery manufacturing joint venture between General Motors and LG Energy Solution, announced plans in September 2026 to upgrade its Spring Hill, Tennessee facility for production of LMR prismatic battery cells.
Facility modifications are expected to begin later in 2026 and are targeted for completion in 2028. The expansion is projected to create approximately 500 additional jobs. The companies say the Spring Hill facility is expected to become the first location globally to mass-produce prismatic LMR battery cells.
The announcement is part of GM's broader multi-chemistry battery strategy. Ultium Cells is already producing or preparing to produce different battery chemistries and form factors, allowing GM to use different technologies for different vehicle and energy-storage applications.
What Is an LMR Battery?
LMR stands for lithium manganese-rich. It is a cathode chemistry designed around a much higher proportion of manganese than conventional high-nickel battery materials.
Manganese is relatively abundant and generally less expensive than nickel and cobalt. GM has described its LMR cathode as using substantially more manganese while requiring little or virtually no cobalt.
The objective is straightforward: combine the cost advantages associated with manganese-rich chemistry with significantly higher energy density than conventional affordable battery chemistries such as LFP.
LMR vs LFP: Why the Difference Matters
LFP has become one of the most important lower-cost EV battery chemistries because of its cost structure, durability characteristics and reduced dependence on nickel and cobalt. GM is already introducing LFP production capability at Spring Hill.
LMR is being positioned differently. GM says its new LMR cells could deliver 33% greater energy density than its best-performing LFP-based cells at comparable cost.
That combination could make LMR particularly attractive for larger vehicles where battery size, weight and cost are significant engineering constraints.
Related battery technology: For a deeper explanation of lithium iron phosphate technology, see our LFP Battery Guide, covering LFP chemistry, safety characteristics, energy density, charging behaviour and EV applications.
What Does 33% Higher Energy Density Actually Mean?
Energy density describes how much usable energy can be stored relative to the size or mass of a battery. Two measurements are particularly important in automotive engineering: gravimetric energy density, measured in Wh/kg, and volumetric energy density, measured in Wh/L.
Higher gravimetric energy density can help reduce battery mass for a given amount of stored energy. Higher volumetric energy density can allow more energy to fit into a similar physical package.
GM publicly describes its new LMR cells as having 33% higher energy density than its best-performing LFP cells, but the company's public announcements do not specify whether this headline figure refers primarily to gravimetric density, volumetric density, or another cell-level measurement.
Therefore, it would be premature to claim that the 33% advantage automatically means 33% lower battery weight, 33% more range or 33% smaller battery packs.
Why LMR Could Reduce EV Battery Costs
Battery chemistry has a major influence on EV cost. High-nickel cathodes can deliver high energy density but rely heavily on relatively expensive nickel and other materials.
LMR shifts the chemistry toward manganese. GM says the higher manganese content can lower material costs while maintaining a higher energy-storage capability than LFP.
There is another important advantage: LMR is being developed in a large prismatic-cell format.
Larger cells can reduce the number of individual cells, interconnections and certain structural components required in a battery pack. That can potentially simplify packaging and manufacturing.
Why GM Is Using Prismatic Cells
A prismatic cell uses a rigid rectangular enclosure. This differs from pouch cells, which use flexible packaging, and cylindrical cells, which use a round metal format.
For large electric trucks and SUVs, prismatic cells can offer packaging advantages because large rectangular cells can make efficient use of the available battery-pack footprint.
GM has specifically linked LMR chemistry with the manufacturing and space-efficiency benefits of prismatic cells.
Which GM Vehicles Could Use LMR Batteries?
GM and LG Energy Solution have identified future electric trucks and full-size SUVs as key applications for LMR prismatic battery cells.
GM has also said it aims to offer more than 400 miles of range in an electric truck using LMR technology while achieving significant battery-pack cost savings compared with current high-nickel battery packs.
GM's Multi-Chemistry Battery Strategy
GM is not treating LMR as a replacement for every other battery chemistry. Instead, the company is building a portfolio that includes different technologies for different applications.
- High-nickel: positioned for applications requiring maximum range and energy density.
- LFP: positioned as a lower-cost chemistry for selected applications.
- LMR: designed to combine higher energy density with lower material cost.
This approach allows GM to match battery chemistry, cell format and pack architecture to the requirements of different vehicles rather than using one battery chemistry across the entire EV portfolio.
The Engineering Challenges of LMR
LMR is not a completely new battery concept. Researchers have studied manganese-rich layered cathodes for decades, but commercializing them at automotive scale has been difficult.
Historically, two major concerns have been short battery life and voltage fade. Voltage fade means that the average operating voltage of a cell can decline as the cathode structure changes during repeated cycling, reducing the amount of useful energy available for a given capacity.
GM says it and LG Energy Solution have developed engineering solutions intended to address these historical problems. These include cathode-material engineering and other proprietary approaches.
What about voltage fade?
One of the classic problems with manganese-rich layered cathodes has been voltage fade, where average operating voltage can decline as the battery ages. GM says its latest LMR development uses proprietary material and process improvements to address historical degradation problems and says the technology is designed to achieve a lifespan comparable with current-generation high-nickel cells. However, long-term real-world fleet data will be needed to establish how voltage stability performs over many years of EV use.
Gas Evolution: Another Major LMR Challenge
Gas generation during cycling has been another important obstacle to commercializing large-format LMR cells.
LG Energy Solution and Seoul National University reported in September 2026 that they identified oxygen-reaction behaviour associated with gas generation and degradation in large-format LMR cells.
Their research found that adjusting the charging and discharging voltage range improved oxygen reversibility. The researchers then optimized operating conditions and formation processes for 40 Ah-class large-format LMR cells.
In their reported testing, the optimized cells retained 92.2% of their initial energy after 883 charge-discharge cycles.
Spring Hill, Tennessee: The Manufacturing Move
The Spring Hill facility is already an important part of GM's North American battery manufacturing network.
Ultium Cells plans to modify the facility so it can manufacture LMR prismatic cells alongside other battery technologies.
The latest announcement says facility modifications will begin later in 2026 and are expected to be completed in 2028. The project is expected to add approximately 500 jobs.
By producing multiple chemistries and cell formats under the same manufacturing organization, GM and LG Energy Solution are attempting to create a more flexible battery-production system.
What LMR Could Mean for EV Buyers
If LMR reaches commercial production as planned, its biggest significance may not be a single headline range number. Instead, the technology could change the cost-performance balance of large EVs.
- Potentially higher energy density than LFP.
- Lower-cost manganese-rich material strategy.
- Large prismatic cells for efficient packaging.
- Potentially lower battery-pack cost than high-nickel solutions.
- Potential application in large electric trucks and SUVs.
The real test will come when production cells are integrated into complete vehicle packs. Pack-level efficiency, thermal management, charging behaviour, durability and real-world range will ultimately determine how much of the chemistry's theoretical advantage reaches consumers.
LMR vs Solid-State Batteries
LMR and solid-state batteries are often discussed together as future EV technologies, but they solve different problems.
LMR is a development of conventional lithium-ion battery technology focused on improving the balance between cost and energy density. Solid-state batteries, by contrast, replace the conventional liquid electrolyte system with a solid electrolyte architecture.
For a deeper explanation of the differences between conventional lithium-ion and solid-state batteries, read: Solid-State vs Lithium-Ion EV Batteries .
What Happens Next?
The immediate priority is converting the LMR technology from development and validation into repeatable mass production.
- Spring Hill facility modifications begin later in 2026.
- Production-design validation and pre-production development continue.
- Large-format LMR cell manufacturing is targeted for 2028.
- Future GM electric trucks and full-size SUVs are expected to be major applications.
- Final vehicle specifications will become clearer as production programs are announced.
DriveSpecLab Take
GM's LMR strategy is significant because it targets a difficult middle ground in EV batteries: more energy density than affordable LFP chemistry without relying on the same material-cost structure as high-nickel cells.
The combination of manganese-rich chemistry and large prismatic cells could be particularly useful for electric trucks and full-size SUVs, where range, battery cost and packaging all matter.
But the technology should still be viewed as an upcoming production technology rather than a proven consumer specification. The most important milestones will be actual production cells, pack-level testing, long-term durability and the specifications of the first GM vehicles that use them.
Key Takeaways
- Investment: GM and LG Energy Solution are upgrading Ultium Cells' Spring Hill, Tennessee facility for LMR prismatic battery production.
- Timeline: Facility upgrades are expected to begin later in 2026, with completion targeted for 2028.
- Energy density: GM says its LMR cells can deliver 33% higher energy density than its best-performing LFP-based cells at comparable cost.
- Density clarification: GM's public announcements do not specify whether the 33% headline figure refers primarily to gravimetric, volumetric or another cell-level energy-density measurement.
- Target vehicles: Future GM electric trucks and full-size SUVs are the intended applications.
- Range target: GM aims for more than 400 miles of range in an electric truck using LMR technology, but this is a target rather than a confirmed production-vehicle specification.
- Engineering challenge: Historical LMR problems include voltage fade and degradation, while gas evolution has also been an important challenge for large-format cells.
- Commercial production: U.S. commercial production of LMR prismatic cells is targeted for 2028.
Frequently Asked Questions
What is an LMR EV battery?
LMR stands for lithium manganese-rich. It is a lithium-ion battery chemistry that uses a high proportion of manganese in the cathode to target lower material costs while maintaining high energy density.
How much better is GM's LMR battery than LFP?
GM says its LMR cells have the potential for 33% higher energy density than its best-performing LFP-based cells at comparable cost. This is a company-stated cell-level comparison and should not be interpreted as a guaranteed 33% increase in vehicle range.
When will GM start producing LMR batteries?
Ultium Cells plans to produce LMR prismatic battery cells commercially in the United States in 2028. Spring Hill facility modifications are expected to begin later in 2026.
Where will GM's LMR batteries be produced?
The planned commercial LMR prismatic-cell production facility is Ultium Cells' Spring Hill, Tennessee operation.
Will LMR batteries give GM EVs 400+ miles of range?
GM aims to offer more than 400 miles of range in an electric truck using LMR technology. However, this is a target and not yet a confirmed EPA-rated production specification.
Has LMR voltage fade been completely solved?
GM says its engineering work has addressed historical LMR problems including voltage decay and short battery life. However, long-term production-vehicle data is still needed before the technology's real-world voltage stability can be fully evaluated.
Is LMR better than solid-state batteries?
They represent different approaches to battery development. LMR is a lithium-ion cathode chemistry designed to improve cost and energy-density balance, while solid-state batteries use a solid electrolyte architecture. Their eventual advantages will depend on production technology, cost, durability and vehicle application.
Related DriveSpecLab Guides
Official Sources
- General Motors — Ultium Cells LMR Production in Tennessee
- Ultium Cells — Spring Hill LMR Battery Production
- General Motors — GM and LG Energy Solution LMR Battery Technology
- General Motors — Why LMR Batteries Could Change the EV Market
- LG Energy Solution — LMR Large-Format Cell Research
- Ultium Cells — Spring Hill, Tennessee
