GM Sells Battery Plant Stake, Shifts Nearly $900 Million to R&D

On August 11, 2026, Samsung SDI announced it would acquire all of GM’s 49.99% stake in the joint venture Synergy Cells, taking full control of the battery plant project in New Carlisle, Indiana. According to reporting by Huxiu’s Auto Business Review, the deal marks GM’s second sale of a stake in a planned cell plant in less than two years. In December 2024, it had sold its interest in the not-yet-operational plant in Lansing, Michigan to LG Energy Solution. This time it is withdrawing from the New Carlisle project, which was under construction. At the same time, GM is scaling back investment in cell production capacity while increasing investment in next-generation cell research and development. At the core is a cluster of R&D facilities totaling nearly $900 million.

What GM wants to shift is capacity risk, not battery technology

The sentence above captures the essence of this strategic shift. The focus is moving toward controlling the right to define technology without holding production assets.

Details of Stake Transfer to Samsung SDI

Synergy Cells was a joint venture project between GM and Samsung SDI. The two companies announced their partnership in 2023 and formally finalized the joint venture plan in 2024. The plan called for investing about $3.5 billion to build a prismatic cell plant with annual capacity of 27 GWh, expandable to 36 GWh in the future. Production was to focus mainly on high-nickel batteries. The aim was to secure cell supply in anticipation of surging demand for electric vehicles. The automaker was to provide funding, vehicle platforms, and long-term orders, while the battery company was to provide material formulations, processes, and mass-production expertise.

Signs of change surfaced in May 2026. Equipment installation at the plant under construction was suspended. Only the outer shell of the building was completed, and the site was sealed off. GM explained it as aligning production capacity with current demand. Three months later, the pause turned into a withdrawal. Samsung SDI positioned the plant as its first wholly operated battery production base in North America. After completion, it plans to first produce energy storage batteries. At the same time, Samsung SDI signed a joint development agreement with GM for next-generation prismatic cells for future electric vehicles. The related products could be produced at the plant. The chemistry system has not yet been disclosed. It is not the finalized plan for LMR prismatic cells being pursued with LG Energy Solution. The stake sale does not mean the end of the technology partnership. GM has shed the burden of construction and operating investment as a shareholder. It will still continue to participate in developing next-generation prismatic cells.

Background and Repurposing of Lansing Plant Sale

GM’s battery manufacturing history predates the Ultium system. The Brownstown battery plant in Michigan began operating in 2009. From early 2010, it mass-produced battery packs for the Chevrolet Volt. Cells at the time were supplied by the former LG Chem. GM handled assembly of battery packs and related equipment. LG Energy Solution was spun off from LG Chem in 2020. It remains one of GM’s most important cell suppliers. Brownstown still produces electric drive units and battery packs for the Corvette E-Ray and battery packs for the Cadillac CELESTIQ. It also handles some prototype manufacturing. The model was for specialist suppliers to provide cells, while the automaker controlled battery packs, thermal management, control systems, and vehicle integration.

Entering the pure electric vehicle era, GM expanded its goals. From 2019 onward, GM set up three plants centered on Ultium Cells, a 50-50 joint venture with LG Energy Solution. The first was in Warren, Ohio. The second was in Spring Hill, Tennessee. The third was in Lansing, Michigan. For Michigan electric vehicle and battery plans alone, GM planned $7 billion in investment. It aimed to build annual pure electric vehicle production capacity of 1 million units in North America by the end of 2025. Securing cell production capacity ahead of demand was seen as essential for entry. Mature cell manufacturing technology was held by battery companies in Japan, China, and South Korea. Continued reliance on external procurement raised concerns about supply shortages and weakened bargaining power in a demand surge.

The turning point came at the end of 2024. In December 2024, GM sold all of its interests in the Lansing Ultium Cells plant to LG Energy Solution. It announced it expected to recover about $1 billion in upfront investment. The third plant, planned at a total cost of $2.6 billion, was removed from GM’s asset portfolio. LG Energy Solution, which took it over, reorganized the plant’s products and customers. In August 2026, the Lansing plant began production. It supplies products for automotive customers including Toyota electric vehicles as well as its energy storage business. Capacity originally planned mainly for GM demand has become a base supplying multiple customers and multiple markets. Even after the two sales, GM retains stakes in the two operating plants in Warren and Spring Hill. It also continues to operate the Brownstown battery pack plant. The strategy has shifted from full-scale expansion to selective ownership.

Stronger R&D System With Nearly $900 Million

Investment

In contrast to shrinking capacity investment, R&D investment has expanded. Two facilities adjacent to the GM Global Technical Center form the core. There is the already-operating Wallace Battery Cell Innovation Center. There is the Anchor-Johnson Battery Cell Development Center under construction. Together they form a battery R&D complex totaling nearly $900 million. The division of roles was described in reporting by Huxiu’s Auto Business Review.

The Wallace Center handles materials, chemistry systems, cell formats, and large-scale prototyping. The Anchor-Johnson Center handles near-production design and manufacturing validation. Its role is to fill the gap between laboratory prototyping and large-scale production. The latter is named after physicist and GM’s first female vice president Betsey Ancker-Johnson. GM expects that once the center is operational, it can shorten new battery development times by up to a year. The aim is to strengthen its voice in joint development. It is a system to engage early in finalizing chemistry systems, cell shapes, performance targets, and manufacturing processes. The goal is to shift from a customer that presents requirements and procures finished products to a co-definer of next-generation cells.

LMR Cell and Sodium-Ion Strategy

A key project for measuring technology leadership is the LMR cell. They are lithium-rich manganese-based prismatic cells jointly developed by GM and LG Energy Solution. Mass production is planned for 2028. Testing equivalent to about 1.4 million miles cumulatively has been completed. Development is through in-house full-size prototyping and validation capabilities. It is an example of the shift from passive procurer to co-definer of cells. It is said to hold patents in materials, electrolytes, and interface engineering. Dependence on LG Energy Solution and Samsung SDI continues for core material patents and large-scale manufacturing experience. The focus is whether R&D strength can be converted into stable mass-production yields and cost advantages. Its true value will be tested at 2028 LMR mass production.

The other pillar is sodium-ion. In 2026, GM will jointly develop sodium-ion cells with U.S. storage company Peak Energy. Under the disclosed partnership structure, GM handles cell development. It retains exclusive manufacturing rights. Peak Energy handles integration into grid and data center storage systems. The products target stationary uses such as grid storage. They are uses that do not prioritize energy density. It is a model that avoids the risk of building a dedicated plant. It is a new model of selective manufacturing in which it handles R&D and retains manufacturing rights. Retaining manufacturing rights for new cells while selling battery plant stakes seems contradictory at first glance. In reality, it is a move to scale back dedicated cell production capacity while reinforcing materials research, prototyping, and production validation capabilities. It cannot complete development and mass production of next-generation cells alone without specialist battery companies. Still, the intent is to engage from the early stages of technology decisions.

Mass-Production Barriers and Technology

Leadership Challenges

Cell manufacturing is a typical heavy-asset business. Even a single plant with annual capacity of around 30 GWh incurs huge fixed costs. A decline in utilization directly worsens profitability. The direct cause of GM’s sale of battery plant stakes is utilization. The background is sluggish pure electric vehicle sales in the United States and serious underutilization. Holding capacity beyond the demand outlook becomes a burden. Even providing funding and vehicle platforms, recovery is difficult without demand. Building a joint venture plant was an option premised on surging demand. Once that premise collapsed, a review of the asset structure was unavoidable.

After the sale, GM trimmed production assets. It continues to accumulate technology assets. The aim is to change negotiating terms with battery companies by holding materials research, prototyping, and validation in-house. It is a position to influence chemistry selection and process finalization. However, the mass-production barrier remains. Large-scale manufacturing experience and yield management are the domain of specialist companies. External partnerships are essential to ensure stable supply and cost competitiveness. The focus going forward is whether claims of technology leadership can be backed up on the mass-production floor.

Editorial Opinion

On short-term impact. In the next 3 to 6 months, restructuring of battery plants in the U.S. is expected to accelerate. Samsung SDI plans to repurpose the New Carlisle plant for energy storage battery production. LG Energy Solution is also expanding supply to multiple customers at the Lansing plant. GM’s capital investment burden will lighten. Freed-up resources are expected to be redirected to launching R&D facilities. This will also affect diversification of cell procurement sources and supply and demand in the energy storage market. On the long-term view. In 1 to 3 years, the division of roles between automakers and specialist battery companies is expected to be redefined. Specialist companies will handle heavy-asset mass production. Automakers will focus on defining materials, formats, and processes. GM’s LMR plan will face its litmus test with 2028 mass production. The key is whether in-house prototyping and validation capabilities contribute to yield improvement. Results in stationary sodium-ion could also broaden supply chain options. Questions from the editors. Can the right to define technology be maintained without mass-production experience on the shop floor. Patents and prototyping capabilities can strengthen bargaining power. The entities that deliver stable quality and cost remain the battery companies. Will the GM model spread to other companies. Balancing externalization of capacity risk with technology involvement will not be easy.

References

• “ 车企造电池的坑，通用先看明白了 “, by 汽车商业评论 — 虎嗅网, 2026-09-24T23:09:44.000Z (ARR)
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