The single most expensive component in an electric vehicle is the battery, and the cell is the heart of the battery. So one of the defining strategic choices an automaker makes is whether to buy cells from suppliers or to build them itself. GM's answer, spelled out across its filings, is a hybrid: a jointly owned manufacturer called Ultium Cells.
In its most recent Form 10-K, filed January 27, 2026 for the year ended December 31, 2025, GM states that its "EV portfolio takes advantage of integrated supply chain development, including battery cell production from Ultium Cells." Prior annual reports describe Ultium Cells as "an equally owned joint venture with LG Energy Solution" and note GM is "mass-producing battery cells" through it. The current filing is on sec.gov, indexed by EdgarBeast.
Why take on cell manufacturing at all? Three reasons recur in the logic of vertical integration. First, supply security: cells were the chokepoint of the EV ramp, and owning capacity insulates you from a supplier's other customers. Second, cost: at scale, capturing the manufacturing margin and tuning the chemistry to your own packs lowers the per-kWh cost that dominates EV economics. Third, roadmap control: co-owning the plant means the automaker has a seat at the table on what chemistry comes next.
The joint-venture structure is the compromise. Building cells from scratch is enormously capital-intensive and requires deep electrochemistry expertise that automakers historically lacked. Partnering with an established cell maker — here, LG Energy Solution — splits the capital, imports the manufacturing know-how, and still gives the automaker ownership and influence. GM's filings even report equity earnings tied to the venture, the financial signature of a true co-owned business rather than a simple purchase contract.
This is the model much of the industry has converged on: not pure buy, not pure build, but co-own. When you read that an automaker has a "battery joint venture," the substance is that it has decided the cell is too strategic to outsource entirely — and too hard to make alone.