Samsung SDI Takes Full Control of Indiana Battery Plant, Shifts Production to ESS Cells

Samsung SDI Takes Full Control of Indiana Battery Plant

On August 14, Samsung SDI announced the completion of its acquisition of General Motors' (GM) 49.99% stake in SynergyCells, the joint venture battery company in New Carlisle, Indiana. With this transaction, Samsung SDI now fully controls the plant's operations. The company stated that the facility will become its first independently operated battery production base in North America, with plans to prioritize the production of energy storage system (ESS) cells to meet demand in the U.S. storage market.

SynergyCells was originally established as a joint venture between Samsung SDI and GM in August 2024, with a total investment of approximately $3.5 billion. The plant was initially designed with an annual production capacity of 27 GWh, expandable to 36 GWh, and was set to produce nickel-rich NCA prismatic cells. However, due to slower-than-expected growth in electric vehicle demand, Samsung SDI decided to adjust its collaboration model and take sole ownership of the Indiana plant.

Prioritizing the Energy Storage Market

Samsung SDI has decided to shift the New Carlisle plant's initial product line to ESS cells instead of the originally planned electric vehicle batteries. In December 2025, the company signed a three-year supply contract valued at over 2 trillion won (approximately $1.35 billion) to provide prismatic lithium iron phosphate (LFP) cells for the North American market starting in 2027. Samsung SDI noted that ESS cells differ from EV cells in design, with the former prioritizing cycle life and cost efficiency over energy density.

Prismatic cells feature a rigid casing design, requiring less external support during module assembly compared to cylindrical cells. They also utilize space more efficiently. These characteristics make them particularly advantageous for energy storage system applications. Despite the shift in product focus, Samsung SDI and GM continue their partnership, having signed a new joint development agreement on the same day to advance prismatic cells that could be used in future electric vehicles.

Market Factors Behind the Adjusted Collaboration Model

Samsung SDI stated that while the acquisition reflects recent market changes, it remains committed to maintaining its strategic partnership with GM. The company did not elaborate on the specific reasons for the slower-than-expected growth in electric vehicle demand or provide updates on the current construction progress or expected completion timeline for the New Carlisle plant. According to the 2024 plan, the plant was originally scheduled to begin production in 2027, but whether the timeline will change following the product line adjustment remains to be seen.

Following the acquisition, GM will no longer hold any stake in SynergyCells, though the technical collaboration between the two companies continues. Samsung SDI emphasized that it may still produce prismatic cells developed jointly with GM at the New Carlisle plant in the future, though no specific timeline has been announced. The company also did not provide further details on the potential impact of the ownership change on local employment or the economy.

Bright Prospects for the Energy Storage Cell Market

As global renewable energy development accelerates, demand for energy storage systems continues to grow. Samsung SDI's decision to adjust its product line underscores its focus on the North American energy storage market. The company stated that ESS cells must balance long-term stability and cost efficiency, and the structural characteristics of prismatic cells align well with these requirements. In the future, the New Carlisle plant will serve as a key production hub for Samsung SDI in North America, supplying critical components for the energy storage market.

Despite the slowdown in electric vehicle market demand, Samsung SDI and GM's collaboration continues to deepen. Their joint development agreement for prismatic cells demonstrates a long-term commitment to future electric vehicle technology. As construction of the New Carlisle plant progresses, Samsung SDI's influence in the North American battery market is expected to grow further.

Samsung SDI Takes Full Control of Indiana Battery Plant, Shifts Focus to ESS Cells