General Motors (GM) is embarking on a transformative journey in electric vehicle (EV) technology. The automotive giant announced its plans to pioneer the use of lithium-manganese-rich (LMR) batteries in its production trucks and full-size SUVs, starting in 2028. This strategic shift represents a significant departure from conventional battery chemistries like nickel-manganese-cobalt (NMC) and lithium-iron-phosphate (LFP), as well as a move away from the pouch cell format that GM has traditionally favored. Simultaneously, GM is embracing prismatic cells for its LMR batteries, marking a dual innovation in both chemistry and cell structure.
General Motors LMR Prismatic Cell
The adoption of LMR chemistry is driven by its potential to bridge the gap between cost-effective LFP batteries and high-performance NMC batteries. GM emphasizes that LMR batteries offer cost advantages similar to LFP while delivering energy density and performance closer to NMC. This balance is achieved by reducing the reliance on expensive and environmentally problematic metals like nickel and cobalt. Instead, LMR batteries utilize a higher proportion of manganese, a more abundant and less expensive material found in the Earth’s crust.
| Battery Chemistry | Energy Density | Cost | Materials |
|---|---|---|---|
| NMC (Nickel-Manganese-Cobalt) | High | High | Nickel, Manganese, Cobalt |
| LFP (Lithium-Iron-Phosphate) | Lower | Low | Lithium, Iron, Phosphate |
| LMR (Lithium-Manganese-Rich) | Medium to High | Medium | Lithium, Manganese |
Comparison of Battery Chemistries
Beyond the chemistry, the shift to prismatic cells is a crucial element of GM’s strategy. Prismatic cells, characterized by their square or rectangular shape, offer a modular and stackable design that facilitates easier integration into battery packs. This optimized fit translates to less wasted space within the pack, resulting in a more space-efficient battery design. While GM’s existing pouch cells also offer neat arrangements, large-format prismatic cells provide additional advantages in terms of module simplification and production efficiency. According to Andy Oury, a battery engineer at GM, prismatic cells enable fewer, larger modules, leading to cost reductions and simplified production processes.
| Cell Type | Shape | Advantages | Disadvantages |
|---|---|---|---|
| Pouch | Flexible, flat | Lightweight, space-efficient | Complex module assembly, cooling challenges |
| Prismatic | Rectangular | Modular, stackable, easier integration | Lower space efficiency compared to pouch cells |
| Cylindrical | Cylindrical | Well-established manufacturing, good thermal management | Lower packing density, complex assembly |
Comparison of Battery Cell Types
The development of LMR batteries has been a decade-long endeavor for GM, with the pandemic accelerating the process. Since 2020, GM has been actively involved in in-house materials research and development, culminating in the production of its first full-size batch of LMR cells in 2023. By 2024, the company had manufactured over a ton of LMR cathode active material (CAM) and secured a vehicle application for the technology. The recruitment of Kurt Kelty, a battery industry veteran from Tesla, further bolstered GM’s battery and propulsion efforts. Initially skeptical of the prismatic cell format, Kelty was eventually convinced by GM engineers of its advantages in energy density and cost.
| Year | Milestone |
|---|---|
| 2020 | Began in-house materials R&D |
| 2021 | Built a demo cathode |
| 2023 | Produced first full-size batch of LMR cells |
| 2024 | Manufactured over a ton of LMR CAM, locked in vehicle application |
GM’s LMR Battery Development Timeline
The development of LMR battery tech is particularly significant for the U.S. as it seeks to establish its own supply chain and reduce reliance on China, which currently dominates the LFP battery market. The U.S. requires a tailored approach to address its unique challenges, such as the economic viability of full-size electric trucks and SUVs. The current battery technology makes these vehicles heavy and expensive, as exemplified by the Hummer EV’s massive battery pack.
GM Wallace Battery Innovation Center Michigan
While prismatic LMR cells are still several years away from mass production, GM’s commitment to this technology, along with Ford’s interest, signals a promising future. Kurt Kelty notes that the flexibility to choose any cell format and chemistry is a significant advantage for battery innovation. With a streamlined decision-making process, GM’s battery teams are empowered to innovate and address challenges effectively. The adoption of prismatic LMR cells is projected to result in 75% fewer parts at the module level and 50% fewer parts at the overall pack level, leading to substantial weight savings and increased energy density.
| Metric | Prismatic LMR Cells | Improvement |
|---|---|---|
| Parts at Module Level | 75% fewer | Significant reduction in complexity |
| Parts at Pack Level | 50% fewer | Simplifies overall pack design |
| Weight Savings | Hundreds of pounds | Enhances vehicle efficiency |
| Energy Density | 33% more | Increased range and performance |
Projected Benefits of Prismatic LMR Cells
