Northvolt, a major Swedish battery maker, filed for bankruptcy in the U.S., seeking to restructure the debt it had taken on to pay for its rapid expansion.

Northvolt, the Swedish maker of battery cells for electric vehicles, said on Thursday it has filed for Chapter 11 bankruptcy protection in the U.S., and said it has secured $100 million in new financing for the process.

Northvolt transformed in a matter of months from Europe's best shot at a homegrown electric-vehicle battery champion to a struggling company.