Tech Insights

Lithium Recovery Technique Could Help Meet Europe’s Raw Material Demand

May 14, 2023 by Shannon Cuthrell

A lithium-ion sieve developed by German researchers can be used to recover lithium from regional geothermal waters in Europe. 

Researchers from Germany-based Karlsruhe Institute of Technology (KIT) and energy firm EnBW recently developed a lithium-ion sieve using a lithium-manganese oxide to “adsorb” lithium—meaning collecting ions on a solid surface—from geothermal brines. 

 

adsorbent to extract lithium from geothermal brines

German researchers recently developed an adsorbent to extract lithium from geothermal brines. Image used courtesy of Monika Bäuerle/Karlsruhe Institute of Technology

 

This would prove useful for unlocking the potential of Europe’s vast network of lithium deposits, some located in Germany’s deep thermal waters. The European Union (EU) is working to shore up its domestic supply of raw materials to meet the high demand for lithium-ion batteries used in electric vehicles and energy storage systems. 

 

How the Lithium-ion Sieve Works

Researchers from KIT’s Institute for Applied Materials–Energy Storage Systems (IAM-ESS) division teamed up with EnBW’s research and development unit and scientists from the Fraunhofer Institute for Chemical Technology and German firm Hydrosion to build and test the sieve. 

Helmut Ehrenberg, the head of IAM-ESS, mentioned in KIT’s press release that geothermal brines contain up to 500 milligrams of lithium per liter. Lithium concentrations reaching 240 milligrams per liter (mg/L) were found in the North German Basis, while up to 200 mg/L were measured in the Upper Rhine Graben. To tap this abundance of critical metal that can be used for high-demand applications such as EVs and energy storage systems, the researchers needed to develop a lithium-selective adsorbent paired with desorption solutions to release the ions from the surface. 

Since lithium-manganese oxide (LMO) has high adsorption capacity and selectivity, the material represents the best option for lithium cation recovery from aqueous solutions. 

The KIT researchers employed hydrothermal synthesis to prepare a lithium-ion sieve material derived from a spinel-type LMO crystal structure. In a lab, they used the sieve to adsorb lithium cations from a generic solution and geothermal brine from EnBW’s power plant in Bruchsal, located in Germany’s Upper Rhine Valley—a region home to one of Europe’s largest lithium reserves. 

The researchers then conducted desorption experiments with various solutions, finding that acetic acid and ammonium peroxydisulfate performed the best, showing high lithium recovery and low manganese ion dissolution. 

 

Implications for Europe’s Raw Material Supply

Overall, these findings introduce a promising technique to recover lithium from Europe’s large volumes of thermal water. The study also comes as the continent is working to shore up its raw mineral supply. The European Union is increasing its deployment of renewable energy, EVs, and other electrification applications. 

The EU aims to slash its greenhouse gas emissions by at least 55% (down from 1990 levels) by 2030, targeting net-zero carbon emissions by 2050. To do that, the European Commission is calling on its 27 member countries to increase their adoption of solar photovoltaic systems, land-based and offshore wind turbines, and electric transportation technologies. With this comes a growing demand for raw materials that would otherwise be sourced abroad from China, South Africa, and the Democratic Republic of the Congo. 

The EU currently relies on imports for most of its critical minerals, such as lithium, cobalt, and rare earth elements. To boost its domestic supply, the European Commission is expanding its continent-wide industrial climate policies, recently introducing a Critical Raw Materials Act to help mitigate the risks and improve the circularity of its supply chain. 

The new regulation sets benchmarks for boosting European countries’ domestic capacities by 2030, including at least 10% of its annual consumption for extraction, 40% of its processing, and 15% of its recycling. 

Elsewhere outside Europe, automakers like General Motors are currently investing heavily in lithium extraction. GM recently led a $50 million funding round in Puerto Rico-based EnergyX, sealing a deal to tap the startup’s lithium offtakes for its battery electric vehicles.