Rio Tinto's $6.7B acquisition of Arcadium Lithium boosts shares, but analysts question the price tag and potential for immediate benefits.

Rio Tinto, one of the world's top metal miners, agreed to buy Philadelphia-based lithium miner Arcadium for $6.7 billion in cash. The big picture: Lithium, which is a key metal inside both EV and stationary storage batteries,

Rio Tinto Group’s takeover offer for Arcadium Lithium Plc has won approval, boosting the world’s second-biggest miner’s bid to become a major producer of the crucial battery material.