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Increasing the Stability of LiMn 2 O 4 Against Harsh Conditions During Lithium Recovery from Real Brine Solutions
Author(s) -
Hippauf Felix,
Abendroth Thomas,
Neidhardt Julia,
Althues Holger,
Aljlil Saad A.,
Alrasheed Radwan A.,
Alyousef Yousef M.,
Kaskel Stefan
Publication year - 2021
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.202100145
Subject(s) - brine , electrochemistry , alkali metal , chemistry , electrode , chlorine , lithium chloride , inorganic chemistry , lithium (medication) , chloride , desalination , chemical engineering , membrane , organic chemistry , medicine , biochemistry , engineering , endocrinology
Brines are abundant waste products from desalination plants and have higher lithium contents than sea water (0.17 ppm). Herein, electrochemical lithium recovery from real brine solutions using Li‐selective LiMn 2 O 4 is reported. Free‐standing electrodes are prepared completely solvent‐free. At low current densities, the complete theoretical capacity of 148 mAh g −1 can be utilized. The process is highly rate dependent due to the lithium concentration in the m m range. The high salt content of the brine depicts a challenging environment for electrodes and reactor materials. Competing earth‐alkali metals lead to scale formation blocking the electrode surface and reducing the electrode capacity for lithium uptake. The high chloride concentration enables the formation of chlorine Cl 2 at potentials < 1 V versus Ag/AgCl competing with the deintercalation of lithium. A combination of commercial antiscalants was used to suppress the formation of CaCO 3 at the electrode prolonging its cycle life. It is shown that a cation exchange membrane not only effectively blocks chloride ions from the electrode but also decreases the Li‐diffusion. Finally, the selectivity of the process is proven in a real brine with a low lithium content (0.7 m m ), and an actual recovery experiment is conducted in a flow setup.