Samsung SDI buys out GM's half of their $3.5B Indiana plant — and switches it to storage

GM is selling its 49.99% stake in the New Carlisle, Indiana battery joint venture to Samsung SDI, handing the Korean maker full ownership. The partners announced the venture in April 2023 and finalized the $3.5B deal in 2024: a 680-acre site making nickel-rich NCA prismatic cells under Samsung's PRiMX brand, 27 GWh of initial capacity scalable to 36 GWh, mass production slated for 2027 and more than 1,600 jobs. Construction was paused earlier this year as US EV demand undershot both companies' plans. Samsung SDI attributed the ownership change to those market changes and says it will complete the plant, using it initially for energy-storage system cells. GM says it will keep working with Samsung SDI.

Why it matters

This is the EV demand miss showing up as an asset transfer rather than a press release. A half-built 27 GWh plant does not become worthless when EV forecasts fall — it becomes a bet on whichever demand curve is still rising, and in 2026 that is grid storage, pulled by the same AI data-center load that is reshaping grid-side procurement across the sector. GM exits the capital commitment and keeps the supply relationship, which is the cheaper half of the deal; Samsung SDI takes the whole balance-sheet risk in exchange for a US plant it controls outright, with cells it can sell into a market that does not depend on any single automaker's volume. The open question is margin: ESS cells are a lower-price product than the automotive NCA prismatics the line was designed for.

What to watch

What the purchase price turns out to be, when construction restarts and at what capacity, and whether the line ever converts back to EV cells if US demand recovers.