Rio Tinto, one of the world’s most profitable companies, faces a tough battle to grow its lithium business, with some of the biggest carmakers prepared to pay a price it won’t match.

Lithium is Rio Tinto’s No. 1 target for deals, but it’s found that companies such as Tesla seem willing to outbid it for a commodity that CEO Jakob Stausholm this week branded “very expensive".

Tesla has been weighing a takeover of miner Sigma Lithium, Bloomberg News reported last week. But with a market value of $3.6 billion, Rio is not interested, a person familiar said at the time.

For Rio, it risks becoming a familiar theme. After two disastrous deals more than a decade ago almost sunk the company, Rio moved to a more conservative footing, focusing on funneling record profits back to shareholders rather than looking to do deals.

Yet the conservative approach saw the company miss out on a host of opportunities in the past five years, from copper to lithium, as Chinese miners were willing to pay more. That approach has drawn criticism from its new Chairman Dominic Barton, who has said that M&A reluctance came at a cost.

Rio is keen to grow in lithium, a key ingredient to make batteries for electric vehicles. So far, it’s bought a lithium mine in Argentina for $825-million, but plans for its flagship Jadar project in Serbia were dashed last year when the government blocked the development after thousands of protesters took to the streets to oppose it.

That’s left the company looking to buy more lithium, asking the biggest investment banks for pitches on miners. Yet so far, it’s finding the asking prices high.

Still, Stausholm said there were opportunities to work with carmakers.

“What the carmaker wants is lithium, but you also need the competency of being a miner,” the CEO said in an interview with Bloomberg TV. “Maybe there’s something that can be done together.”

Rio’s CFO Peter Cunningham said in an interview Wednesday that the company must remain disciplined.

“We certainly see an opportunity to invest in growth, but we will only do so where we see that value,” Cunningham said. “We will just keep looking until we find the opportunities where we see the value. If we can’t, we won’t invest.”