Peter Carlsson, the CEO and co-founder of Northvolt, is resigning, the Swedish electric vehicle battery cell manufacturer announced on Friday, just a day after the company sought Chapter 11 bankruptcy protection in the United States.

Northvolt went in a matter of months this year from being Europe's best shot at a home-grown electric-vehicle battery champion to racing to stay afloat, hobbled by production problems and dwindling funding.

It now needs to raise between $1 billion and $1.2 billion to restore its business, the outgoing CEO told reporters.

"Personally, this is an emotional day," Carlsson said. The former Tesla executive, who co-founded the company in 2016, said Northvolt had been "like a baby" to him.

The Chapter 11 filing allows a period during which the company can reorganize and ramp up operations while honoring customer and supplier commitments and ultimately position itself for the long term, he said.

The lithium-ion battery maker said on Thursday it only had cash to support operations for about a week, and that it had secured $100 million in new financing for the bankruptcy process to allow it to continue.

The company, which employs around 6,600 staff across seven countries, said in its Chapter 11 filing it expects to complete the restructuring by the first quarter of 2025.

Carlsson will take on a role as senior adviser and remain a member of the board, the company said, adding that the search for a new CEO has started.

In the meantime, Northvolt will be led by Chief Financial Officer Pia Aaltonen-Forsell and its president of battery cells, Matthias Arleth, who takes up a new role as chief operations officer.

On Monday, Reuters reported that Northvolt had missed some in-house targets and curtailed production at its battery-cell plant in northern Sweden, underscoring the challenge of ramping up output.

"In hindsight, we were over-ambitious on the timing in which we could achieve it," Carlsson said of the production target, adding that the company is now working towards improving its output.

Northvolt said on Thursday it is conducting a search for one or more partners to finance its restructuring and return the company to long-term sustainability, including the completion of major battery plants in Germany and Canada.

"Any and all interested parties, regardless of their desired transaction type, are encouraged to contact Rothschild as soon as possible and submit proposals by early December," Northvolt said in its Chapter 11 filing at a Texas court.

Failing this, Northvolt said it has also engaged financial services company Hilco Global to assist with "an orderly liquidation process if necessary".

"Northvolt trusts that it can build on its billions of dollars of investment and groundbreaking facilities and technology to achieve a value-maximizing recapitalization or sale in Chapter 11," it said.