The current global energy crisis further accelerates the world energy transition towards renewable energies. The demand for lithium raw materials, which are used to make batteries, is expected to grow exponentially in the next years, leading to a potential supply shortage.[1] For this reason, much effort has recently been invested in developing technologies for direct lithium extraction (DLE) from brines. One of the new DLE technologies that is under development is the electrochemical ion pumping method, which is particularly attractive due to its low energy consumption and the avoidance of the use of chemicals.[2] This method has been tested using intercalation materials as the positive electrode that show outstanding selective properties towards lithium, especially LiMn2O4 (LMO).[3] In this work, the performance of LMO porous electrodes in different compositions of geothermal brine has been studied. Electrodes with variable mass loading were manufactured and tested under different discharge current densities and hydrodynamic conditions. These parameters were optimized to maximize the lithium recovery capacity of the electrodes from a geothermal brine with a lithium concentration between 30 mM and 3 mM.

[1] C. B. Tabelin, J. Dallas, S. Casanova, T. Pelech, G. Bournival, S. Saydam, I. Canbulat, Miner Eng 2021, 163, DOI 10.1016/j.mineng.2020.106743.
[2] L. Baudino, C. Santos, C. F. Pirri, F. La Mantia, A. Lamberti, Advanced Science 2022, 9, DOI 10.1002/advs.202201380.
[3] G. Zhou, L. Chen, Y. Chao, X. Li, G. Luo, W. Zhu, Journal of Energy Chemistry 2021, 59, 431–445.