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., dealing a blow to Europe's hopes that its most developed battery player would reduce Western car makers' reliance on Chinese rivals.

Northvolt, a Swedish-based lithium-ion battery manufacturer backed by Volkswagen Group and others, has filed for bankruptcy protection in the United States. The company was hailed as one of Europe's biggest hopes against China's EV battery supremacy.