Rio Tinto will spend $US6.7 billion ($9.9 billion) consolidating the world’s biggest lithium resources, betting that the commodity – an essential component in electric vehicle batteries – has a profitable future despite its peers renouncing it for surer bets such as copper.

Rio became the first of the big diversified miners to claim a major lithium business on Wednesday when it struck a friendly, all-cash takeover deal for dual-listed producer Arcadium Lithium.