New Extraction Method Could Lower Lithium Battery Prices

A Massachusetts Institute of Technology (MIT) research team has developed a new method to extract lithium from rock that could lower battery costs by reducing the energy use and waste associated with hard rock lithium extraction, according to a study published in Science.

Lithium-ion batteries currently dominate the market because they are produced at scale and supported by a mature global supply chain. This keeps their prices competitive compared to alternative battery technologies. However, this advantage depends heavily on affordable lithium, much of which comes from South American brine deposits.

While lithium itself is abundant, low-cost and easy-to-access deposits are limited. This has kept spodumene, a lithium-rich hard rock mineral, in focus. It is the world’s most common lithium ore, but processing it remains expensive.

The standard method for extracting lithium from spodumene involves heating the ore to around 1,000°C and treating it with sulfuric acid. The process consumes significant energy and produces sulfur waste.

Researchers at MIT and their partners have proposed a lower-temperature alternative. Their method uses an ammonium fluoride solution heated to about 70°C to break down spodumene. The reaction separates the ore into three streams: lithium, silicon, and aluminum.

Lithium remains in the solution as lithium fluoride, which can be used directly to make battery electrolytes. It can also be converted into lithium nitrate and lithium oxide, both of which are commonly used in battery manufacturing.

The silicon stream is easier to process. When ammonia is added, silicon converts into silicon dioxide and precipitates out. This byproduct can be used in concrete, which may help reduce overall processing costs.

Aluminum requires the most energy in the new process. After the initial separation, it is heated in stages to 300°C and then 700°C to produce high-purity aluminum oxide. Unlike the conventional method, however, the energy-intensive step comes later rather than at the start of the process.

Another key part of the breakthrough is chemical recycling. Ammonia and hydrogen fluoride produced during the reactions are reused to recreate ammonium fluoride. This helps reduce waste and material loss, although hydrogen fluoride still needs careful handling.

The economics also look promising. Conventional spodumene extraction costs about $9,000 per tonne of lithium. The new process could reduce that figure to just over $5,000 per tonne, making it comparable to high-quality brine extraction. Revenue from silicon and aluminum byproducts could bring costs down further.

However, the final cost will depend on ore quality, market prices, and the infrastructure needed to scale the process. Even so, the research offers a new approach to lithium supply by focusing on how the mineral is extracted, not only where it is found.