Long-Duration Battery Startup Form Energy Raises $450 Million

A startup developing iron-air batteries that could store renewable power for several days is raising $450 million from backers including steelmaker ArcelorMittal SA and TPG

Form Energy Inc. plans to use the funds to build its first big manufacturing facility and begin selling to customers. The private funding round more than doubles the total equity Form has raised in its five-year history, company officials said.