The U.S. Department of Defense is buying lithium for its strategic stockpiles as the nation ramps up efforts to reduce supply risks for critical minerals. 

The Defense Logistics Agency is seeking offers for almost 36 million pounds, about 16,000 tons, of battery-grade lithium carbonate over the next five years in a contract worth as much as $300 million, according to a tender document published on a U.S. government website dated July 2. 

The metal is a key ingredient for batteries used in electric vehicles and energy storage systems. Lithium carbonate prices have surged by more than a third so far this year on optimism over demand and supply uncertainties from major production hubs including China and Zimbabwe. 

The DLA, responsible for managing the National Defense Stockpile that secures metals for U.S. military needs, had sought information for the potential stockpiling of critical minerals including lithium in March. 

Critical minerals have become a political priority for the U.S. in order to slash reliance on China. Most recently, the U.S. Army struck deals with several companies to build processing plants for the materials on military bases around the country. Earlier this year, the White House launched Project Vault, a $12 billion critical minerals stockpiling initiative for the private sector. 

In its tender documents, the DLA asked suppliers to propose fixed prices for the supplies over five years. It stated that the government was intending to spend a minimum of $1 million and a maximum of $300 million on the contract. The deadline for proposals is July 17.