Posco Holdings holds a ceremony to celebrate the first-phase completion of its lithium hydroxide plant in Guemes, Salta Province, Argentina, on Thursday (local time). (Posco Holdings)

Posco Holdings announced Sunday it has completed the first phase of its lithium hydroxide plant in Argentina, a key step in securing a stable supply of the key material for electric vehicle batteries.

Located in Guemes, Argentina, the plant will produce 25,000 tons of lithium hydroxide annually, sourced from the lithium-rich Hombre Muerto salt flat, where Posco holds mining rights. The output is enough to power 600,000 EVs, making it the largest brine lithium facility operated by a single company in South America and Argentina’s first commercial lithium hydroxide production site.

The project is part of a three-phase plan to reach 100,000 tons of annual lithium hydroxide production, a key material for EV battery cathodes. Posco is also using its proprietary lithium extraction technology to reduce production costs.

Posco acquired rights to the Hombre Muerto salt flat in 2018 and discovered that the site contains 13.5 million tons of lithium, six times more than initial estimates.

“This plant represents a significant step toward Posco’s goal of becoming a leader in the global lithium industry,” Posco’s head of the battery materials division Kim Jun-hyung said.

The $830 million Argentine plant is expected to create over 4,800 jobs and strengthen local businesses through partnerships with more than 60 suppliers.

The second phase, adding another 25,000 tons of capacity, is set for completion by late 2025.

Posco is also boosting ore-based lithium production in South Korea to 43,000 tons annually and exploring new projects in Chile and North America.