A slump in the price of lithium, a key raw material in electric car batteries, is dragging on China's mining of the ultralight metal which together with a costly extraction process is prompting a reassessment of output growth and new project plans. Softening EV demand has knocked down global lithium prices, with a basket tracked by Benchmark Mineral Intelligence plunging more than 80% in the past 12 months. In China, which accounted for about a quarter of the world's mined lithium output in 2023, analysts expect the mining of lepidolite - a hard rock ore that is relatively expensive for producing lithium - to take a hit as a prolonged price slump makes costly production unsustainable.