Researchers at the Australian National University have developed a selective membrane technology that can extract lithium directly from underground brines, potentially opening up massive lithium resources in central Australia that are currently uneconomic to exploit.

The technology uses specialised membranes that selectively allow lithium ions to pass while blocking other dissolved minerals. This direct extraction approach is much faster and uses less water than conventional evaporation methods, which require vast solar ponds and take 18-24 months to produce battery-grade lithium carbonate.

Australia is the world’s largest lithium producer, but nearly all production comes from hard-rock mining of spodumene ore in Western Australia. That ore is shipped to China for processing into lithium chemicals used in batteries. There’s been persistent criticism that Australia exports raw materials rather than capturing more value through downstream processing.

Brine-based lithium production, which dominates in South America, is generally cheaper than hard-rock mining. But Australia’s underground brines are chemically different from South American salars, containing higher concentrations of magnesium and other interfering elements that make conventional extraction methods less effective.

Professor Richard Piner, who leads the research at ANU, explained that the membrane technology solves this selectivity problem. “We can extract lithium efficiently even from brines with high magnesium-to-lithium ratios. That opens up resources that were previously considered too difficult to process.”

Several Australian companies have explored brine lithium deposits in South Australia and the Northern Territory but struggled with processing challenges. The deposits are substantial, potentially containing millions of tonnes of lithium, but conventional technology couldn’t extract it economically.

The ANU membrane system uses a multi-stage process where brine is pumped through a series of selective membranes, progressively concentrating lithium while removing interfering elements. The process takes days rather than months, and water usage is about 90% lower than evaporation ponds.

That water efficiency matters in arid central Australia where fresh water is scarce. Conventional evaporation operations require large volumes of water for washing and processing, plus significant land area for ponds. The membrane approach has a much smaller footprint.

The technology builds on research in ion-selective membranes originally developed for water desalination and industrial water treatment. Adapting those membranes for lithium extraction required understanding how different ions interact with membrane materials under various conditions.

The research team collaborated with custom AI development specialists to build models predicting membrane performance based on brine composition and operating conditions. Those models helped optimise membrane design and process parameters without running hundreds of expensive experiments.

The ANU technology is now being commercialised through a startup called LithiaTech, which has raised $25 million in Series A funding to build a pilot plant in South Australia. The pilot will process brine from Lake Torrens, a salt lake that sits above lithium-rich aquifers.

If the pilot succeeds, a commercial facility could begin production by 2028. The project has attracted interest from battery manufacturers in Asia who want to diversify their lithium supply chains beyond China.

Lithium demand is growing rapidly driven by electric vehicle production and grid-scale energy storage. Most forecasts predict supply deficits emerging in the late 2020s as demand growth outpaces new production capacity.

That supply tightness is driving innovation in lithium extraction and processing. Beyond direct extraction from brines, researchers are working on recovering lithium from geothermal fluids, oil field brines, and even seawater, though most of these approaches remain early-stage.

The economic case for Australian brine lithium depends heavily on processing costs and product quality. The membrane technology produces lithium chloride solution that still needs further processing to create battery-grade lithium carbonate or lithium hydroxide. Adding that downstream processing in Australia would capture more value but requires additional capital investment.

Some critics argue that government support for lithium processing is misguided because Australia lacks the integrated battery supply chains that would justify local processing. They contend it’s more economically efficient to export spodumene and let countries with established battery industries do the processing.

That debate reflects broader questions about industry policy and whether governments should try to build domestic capability in strategic industries or simply focus on areas where Australia already has comparative advantage.

The federal government’s Battery Manufacturing Grant program, announced in 2024, provides $500 million in funding to support downstream lithium processing and battery component manufacturing. LithiaTech has applied for funding but hasn’t received approval yet.

Environmental groups have raised concerns about brine extraction’s impact on groundwater systems. While the membrane technology uses less water than evaporation, it still involves pumping substantial volumes of brine from underground aquifers. The effects on aquifer pressure and water quality need careful monitoring.

LithiaTech argues that the brines they’re targeting are too saline for any beneficial use and that extraction won’t affect freshwater aquifers. They’ve commissioned hydrological studies to model impacts, though some environmental groups remain skeptical.

The regulatory approval process for new lithium projects in Australia has become more rigorous following community opposition to several proposed mines and processing facilities. Proponents now need to demonstrate not just technical and economic viability but also social license from affected communities.

Whether membrane-based lithium extraction achieves widespread adoption in Australia will depend on pilot plant results, capital costs, and lithium prices. If it works, it could significantly increase Australia’s lithium production and shift more processing onshore.