"The rapid electrification of the automotive market has led to massive investments in electric vehicle and lithium-ion battery production in the United States, creating a critical need for lithium hydroxide produced in the US," Piedmont's Keith Phillips said.

"Our Tennessee Lithium operation should play an important role in helping to mitigate supply shortages in the American EV industry and battery supply chain, particularly in the wake of recent legislation incentivizing the use of domestically sourced critical materials and providing tax credits for US producers," he said.

The production target for the Tennessee facility, to be located in McMinn County, is of 30,000 tonnes per year of lithium hydroxide, which is to complement the company's Carolina Lithium operation to bring its total US-based production capacity to 60,000tpy by 2026. That compares to total current US production of 15,000tpy, Piedmont noted.

First production from Tennessee Lithium is scheduled for 2025.

Piedmont is planning to invest about US$600 million into the development of the operation.

The plan is for the Tennessee facility to convert spodumene concentrate sourced from Piedmont's international projects.

Piedmont has partnerships in Quebec, Canada, with Sayona Mining and in Ghana with Atlantic Lithium.

Piedmont's share price was A$0.85 (US$0.58) on 5 September, giving the company a market capitalisation of A$1.52 billion.