Fraunhofer ISE Launches ‘ThermIon’ Project for Lithium Extraction from Geothermal Brine

The Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE), along with partners from science and industry, has launched the "ThermIon" project to develop direct lithium extraction (DLE) technology. The initiative will use the "lithium ion pump" process to extract lithium from geothermal brine in Germany's Upper Rhine Graben region.

The ThermIon project addresses the entire process chain, including pre-treatment of brine, lithium extraction, lithium carbonate or hydroxide crystallization, and controlled brine return. The key challenge is to selectively extract lithium from geothermal waters without disrupting the complex geochemical balance, which could lead to the unwanted precipitation of silicates and calcites that pose operational risks.

While several processes for lithium extraction from thermal water are in development, none are yet market-ready. ThermIon aims to create an environmentally friendly, economically feasible DLE technology. The process relies on the "lithium ion pump," which uses an electric field to store lithium ions in a lithium manganese oxide electrode and then releases them in a recovery solution when polarity is reversed. This approach yields a concentrated lithium chloride solution of high purity.

Project manager Dr. Joachim Koschikowski expressed optimism about scaling up the technology, aiming for future lithium extraction directly during geothermal plant operations to improve Europe's raw material supply.

The ThermIon technology could be applied to other geothermal sites in the Upper Rhine Graben, with results transferable to 13 planned geothermal projects in the region. The technology also holds potential for extracting other valuable materials.

The project is funded by the Federal Ministry for Economic Affairs and Climate Protection (BMWK) with around €2.6 million over three years.