GM will commit $625 million toward what’s likely to be one of the biggest U.S. lithium mines, reinforcing the automaker’s efforts to secure domestic supply of the battery metal critical for EVs.

A surge in battery metal prices means it could take several years longer for electric vehicles to become as affordable as conventional cars, according to BloombergNEF.

Cobalt prices were surging so much last year that thieves were carrying out elaborate heists at warehouses in Europe’s busiest port. Now, prices are in free fall, and mining companies are taking the financial hit.