MELBOURNE (Reuters) - Australia, home to the world’s second-biggest cobalt reserves, is seeing a rush of interest in projects still years from production as makers of batteries used in electric vehicles (EVs) seek supplies of the metal from a more costly but less risky source than top miner, the Democratic Republic of Congo.

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As auto makers seek to develop greener cars, shares in Clean TeQ CLQ.AX - owner of one of the largest cobalt deposits in Australia - have trebled this year. Minnows Cobalt Blue COB.AX, Australian Mines AUZ.AX, Artemis Resources ARV.AX and Aeon Metals AML.AX have also seen shares surge.

On Friday, Aeon, developing a copper-cobalt project in Queensland, raised A$30 million ($23 million) from institutional investors.

Investor interest has surged further since Amnesty International reported as much as a fifth of the DRC's cobalt was artisanally mined in dangerous conditions, involving women and children. Giants like Toyota 7203.T and Volkswagen VOWG_p.DE pledged last month to uphold ethical standards in buying cobalt and other minerals needed for EVs.

“We have 10 (battery making) firms in discussions,” said Australian Mines Managing Director Benjamin Bell, citing advanced talks with firms from Germany, Japan, China and South Korea to secure offtake for its Queensland Sconi project. Sconi is expected to produce 2,500 tonnes of cobalt and 17,500 tonnes of nickel annually after production starts in late 2019.

“The reason they are contact with us is they can see that cobalt out of the DRC is probably not going to be acceptable for their users over time,” Bell told Reuters.

Australia is rich in cobalt, mined as a by-product of copper and nickel, holding some 1.1 million tonnes of reserves or 15 percent of world supply. That’s less than a third of the DRC’s reserves, but around five times that of Canada, according to the U.S. Geological Survey.

“To be honest, costs in Australia are much higher than DRC, but half our revenue is cobalt and half nickel. The battery makers are talking to us saying that they would take both,” Bell said.

Clean TeQ began life as a water treatment technology firm but acquired a cobalt-nickel-scandium deposit in 2014 and is now capitalized at A$832 million.

“We are talking to many people regarding offtake and the discussions are ongoing,” a spokesman said.

Meanwhile Artemis Resources plans to reprocess ore stockpiles from a shuttered mine in the Pilbara from the middle of next year. It is not in formal offtake negotiations, but has been speaking with Chinese and American firms, director Ed Mead told Reuters.