Who makes the cell
The battery partnerships between American carmakers and Korean cell makers are coming apart. One supplier is on both sides of it.
Who actually makes the cells, and what happened to the deals.
Ford and SK On are dissolving BlueOval SK, the joint venture that built the Kentucky plant. Completion was expected in the first quarter of 2026. Before it ended, cells from that plant went into the F-150 Lightning and the E-Transit.
The same supplier is going the other way with Hyundai: SK On's joint venture with Hyundai Motor Group is scheduled to start production in 2026.
GM and LG Energy Solution still run Ultium Cells, but the shape of it changed. GM sold a stake in one plant, and the Tennessee site was retooled to make lithium-iron phosphate cells for grid storage rather than for cars. The Ohio plant restarted EV cell production in August 2026 after a seven-month pause.
Tesla keeps buying from Panasonic, which supplies it from Nevada and now from Kansas as well.
And it is not only Ford. Samsung SDI and Stellantis have been in talks to liquidate StarPlus Energy, their Indiana venture - the third of the three big Korean-American battery alliances to be scaled back or unwound.
Why it matters: a car company that owns half a cell plant is committed to that chemistry, that partner and that factory for a decade. Unwinding one is not a supply tweak - it is a bet being cancelled, usually because EV volumes came in under the plan the plant was sized for.
One caveat on reading this frame: every carmaker here buys from more than one cell maker. The line shows the partnership that defines its US cell supply, not its only source.
