The exploration company, founded and headed by ex-banker Jeremy Wrathall, plans to extract lithium from brine heated by the earth's core within three to five years to meet an expected boom in demand from electric vehicle battery manufacturers.

The UK government in August invested in Cornish Lithium's pilot plant in the southwest county of Cornwall, which will cost 4 million pounds to build. The size of the government's investment was not disclosed.

The miner is considering another round of crowdfunding and a listing in London in two to three years, Wrathall told a virtual news conference. It raised 1.4 million pounds through crowdfunding last year.

Still, Cornish Lithium faces an uphill battle as investment into lithium producers has dried up due to low prices, a situation worsened by the financial fallout from coronavirus.

"It's a positive move for the UK but still in the very early stages," said Andy Miller, an analyst at consultancy Benchmark Mineral Intelligence, adding that raising capital to fully fund the project could be a major hurdle.

Cornish Lithium sampled geothermal water used to produce power from the United Downs Deep Geothermal Power Project with its partner Geothermal Engineering.

The company plans to use new technologies to extract lithium that was found in the water in "globally significant" quantities when compared to other geothermal projects, and with low impurities, it said.

The process eliminates the need for large evaporation ponds seen in South America's lithium operations, where a large chunk of the world's lithium is sourced.

While lithium from Argentina and Chile is of higher grade than geothermal sources, concerns over sustainability have plagued the region's miners which extract their product from pools of brine beneath the world's driest desert.

China, the world's top lithium consumer, dominates the battery supply chain but governments in the West are pledging more funds to domestic mines and industries.

(Reporting by Zandi Shabalala; Editing by Jan Harvey and Elaine Hardcastle)