Billions of EV Battery Aid in Balance as US Tweaks Climate Rules

The interpretation of a few words of regulation by the US Treasury Department could upend expectations for how tens of billions of dollars in new electric-vehicle tax incentives will be distributed, according to Bloomberg discussions with a dozen manufacturing executives, battery analysts and government officials.

At stake over the coming weeks is the extent to which a critical part of the battery supply chain will end up being made in North America or remain where it’s currently concentrated, in Asia.

“There are specific factories — and there are thousands of jobs tied to those — that are hanging in the balance,” said J.B. Straubel, the founder ...