SHANGHAI (Reuters) - An estimated 5 million tonnes of lithium deposits have been found in China’s southwestern province of Yunnan, scientists said, potentially curbing the nation’s reliance on imports of the material, used in electric vehicle batteries.

The Institute of Geochemistry, under the Chinese Academy of Social Sciences, said in a statement on its website on Monday that it had made the discovery. State media such as the China Daily newspaper reported the find on Wednesday.

Demand for lithium is growing rapidly as some consumers shift away from cars powered by fossil fuels.

The institute estimated that roughly 340,000 tonnes of lithium oxide were deposited in a test site of 7.2 square km, indicating the amount of lithium oxide in the entire area could exceed 5 million tonnes.

“With society’s expectations of longer lasting battery power for portable devices and the increase in electric vehicles, the demand for lithium has increased sharply,” the China Daily quoted Wen Hanjie, a researcher involved in the discovery, as saying.

“But we also see a high dependence on lithium imports as about 80 percent of lithium used in China between 2011 and 2015 was from overseas ... To find our own lithium resources is an urgent need.”

The Chinese government has previously expressed concern about its overseas dependence for materials such as lithium, which it sees as key to the development of strategic emerging industries such as rechargeable battery production.

The world’s largest reserves of lithium can be found in countries including Bolivia, whose Uyani salt flats has at least 21 million tonnes of lithium.