Tesla is moving forward with plans to build a lithium refinery on the Texas Gulf Coast in a bid to gain more control over the supply chain for electric vehicle batteries.

Chief Executive Officer Elon Musk confirmed the move Wednesday on a conference call in answer to an analyst’s question on progress developing the company’s new 4680 battery cell technology.

The Austin, Texas-based company has been weighing the project for months, as Bloomberg News previously reported, but had been considering at least one other site in Louisiana. The company has told state regulators it plans to build a battery-grade lithium hydroxide refining facility near Corpus Christi that would process raw ore material into something more production-ready.

Musk called lithium prices “crazy expensive” and has repeatedly encouraged entrepreneurs to start refining lithium as a way to ease supply bottlenecks of the key material used in lithium-ion batteries.