Navigating the Landscape of Direct Lithium Extraction Technologies

 

 

With rising global demand for Li-ion batteries comes a revolution in the way lithium is extracted from natural resources. Conventional extraction methods such as hard rock mining and brine evaporation are inefficient, difficult to scale, and damaging to the environment - leading to the emergence of direct lithium extraction (DLE) as a selective method of production. DLE includes a wide spectrum of technologies, each with its own development, performance, and challenges which will shape their adoption in the commercial market. IDTechEx's newly updated "Direct Lithium Extraction 2026-2036: Technologies, Players, Forecasts" report lends greater insight into each of these technologies, highlighting how DLE will drive the lithium market to be worth US$52 billion by 2036.

 

 

 

 

Virtually all commercial-scale DLE plants currently make use of adsorption DLE. This is the most mature and developed of the DLE process types, with the key materials required first developed in the 1970s and the first commercial plants operating since the 1990s. These processes make use of specialized aluminium-based sorbent materials with high lithium affinity to adsorb lithium out of brines. The captured lithium can then be released through desorption using a water strip solution. The result is a lithium-rich eluate that can be further purified into battery-grade lithium.

 

Adsorption offers a step change improvement in lithium recovery compared to conventional brine evaporation processes (upwards of 80% yield for adsorption vs. ~40% for evaporation). The use of a strip solution of pure water is also generally seen as quite sustainable, not requiring additional solvents or reagents for desorption.

 

However, adsorption falls short compared to other DLE processes in certain areas. For one, a lithium recovery of 80% is relatively low given that some DLE process types can already far exceed this - ion exchange DLE is often reported to reach 96% recovery while electrochemical DLE can reach over 99% recovery. Further, the aluminium-based sorbent materials often work best at elevated temperature of 40-90⁰C, requiring ambient temperature brines to be heated before extraction, increasing the energy and costs required.

 

With these shortcomings in mind, resource owners and technology developers are looking towards other DLE process types for more efficient and sustainable extraction.

 

 

 

Ion exchange is an emerging DLE technology which, while still pre-commercial and not as developed as adsorption, shows strong market potential, and IDTechEx's new report expects ion exchange could be poised for growth in the next decade. Ion exchange works in a similar way to adsorption DLE, using an adsorption-desorption process to capture and then release lithium. Ion exchange sorbents are typically manganese- or titanium-based, which can be more costly than a mature and low-cost aluminium-based sorbent.

 

Crucially, ion exchange achieves desorption through the use of an acid strip solution such as sulphuric or hydrochloric acid. This change significantly increases the lithium recovery that can be achieved by the process, which can be as high as 96%. This makes ion exchange DLE well-suited to the commercialization of geothermal and oilfield brines - both sources that have far lower lithium content and more contaminants than conventional continental brines, requiring greater selectivity in extraction. Geothermal brines are found in large quantities in Europe and oilfield brines are prevalent in North America, hence, ion exchange DLE could be key in unlocking lithium supply independence for these regions.

 

Ion exchange processes also do not require the additional heating that adsorption processes use. However, the use of acids does lead to higher operational costs, especially if these acids cannot be generated on-site. Acid use also takes away from the sustainability credentials of DLE processes, generating more waste and accelerating sorbent degradation.

 

 

Beyond ion exchange, solvent extraction and membrane DLE processes are also emerging and seeing increased development and investment. Solvent extraction relies on bespoke solvents with high lithium affinity to extract lithium from brines. However, there is a lack of suitable solvents that can be used for this currently, with far more development needed to produce a low-cost, high-yield, and sustainable solvent that can allow for greater adoption of solvent extraction DLE.

 

Membrane DLE has seen more significant interest from major players due to the crossover between DLE membranes and membranes for other industrial applications. However, present-day membranes are not yet lithium-selective enough to enable lithium extraction on their own, instead relying on adjacent adsorption or ion exchange units to assist in extraction. Additionally, membranes are susceptible to fouling processes, wherein contaminants from brines can accumulate and clog up the pores of membranes over time. Brines with greater contaminant contents can cause accelerated fouling, which can shorten the lifetime of membranes and require more frequent replacements at higher costs. Hence, IDTechEx expects that the economics of membrane DLE will be highly sensitive to brine contents - more so than any other DLE technology.

 

 

Finally, technologies such as electrochemical and precipitation DLE are also in development, though these are far less mature technologies. Electrochemical DLE has only recently reached pilot scale, but in theory could allow for maximum lithium recovery and selectivity - potentially creating future opportunities to extract lithium from sweater. Meanwhile, precipitation is even less developed, currently limited to laboratory scale, but it has the potential to simplify the extraction process and greatly reduce energy consumption. While these technologies could continue to garner investment, they are not likely to see market uptake within the coming decade.

 

 

While DLE projects still face challenges at present, their adoption is trending upwards and they will have a significant impact on the future of the lithium market. The different DLE technology types are all seeing accelerating investment and interest and each will have a role to play, though adsorption is expected to remain the dominant technology. However, as technologies continue to mature, it will be their efficiency, sustainability, and financial viability that determine which get used and which get left behind - with technologies including ion exchange likely to see growing demand.

 

 

For more information on this report, including downloadable sample pages, please visit www.IDTechEx.com/LithiumExtraction, or for the full portfolio of related research available from IDTechEx, see www.IDTechEx.com.