(Corrects materials used in battery to iron, air, and water from iron, steel, and water in paragraph 4)

WASHINGTON, Dec 22 (Reuters) - Form Energy Inc, a startup hoping to make long-duration storage batteries from materials including iron to store power from renewable energy, will partner with West Virginia to build a manufacturing plant in the state, the company and politicians said on Thursday.

The plant is slated to be built starting next year in Weirton, once a top steel making town.

West Virginia Governor Jim Justice and Form Energy, backed by supporters including Bill Gates' Breakthrough Energy Ventures, said the plant will be built with a total investment of up to $760 million. They said the factory will begin making battery systems in 2024 and to create at least 750 jobs in the state, which has suffered for years from a lack of high paying jobs as coal production falters amid the energy transition.

Form Energy aims to build batteries using iron, air and water. It says the batteries will be charged by rusting iron pellets and reversing that process to turn them back to iron. Form says the batteries can store power for days, much longer than ones based on lithium-ion.

The private company has not released data showing how the batteries will store power on a commercial basis.

Form Energy intends its batteries to store electricity from solar and wind power that only operate intermittently, when the sun shines and wind blows.

Company co-founder and chief executive Mateo Jaramillo said Weirton was chosen from among 500 locations across 16 states. Jaramillo said Weirton has "the rich heritage and know-how to make great things out of iron."

In October, Form said it had raised about $452 million from backers including Arcelormittal SA.

Senator Joe Manchin of West Virginia, a conservative Democrat and founder and partial owner of private coal brokerage Enersystems, who has been reluctant to rein in fossil fuels, praised the project.

"The path forward is innovation, not elimination, and with this announcement West Virginia and Form Energy are doing just that," Manchin said in a statement. (Reporting by Timothy Gardner; editing by Grant McCool)