Lithium Recovery from Brine Using Commercial Lithium Iron Phosphate (LFP) — 78p — ViolaMay Simwanza, Dr. Brett Carlson

Lithium is an alkali earth metal whose demand, especially for use in materials and sustainable mobile energy, is growing. Most of the world’s total lithium product is extracted from salt lake brines. Traditional chemical extraction methods are time-consuming and produce unnecessary chemical waste. Electrochemical extraction, which instead uses an electrical current, has been proposed as an alternative method for the recovery of lithium from brine with the benefits of efficiency, selectivity, and the ability to be used for low concentration solutions. Successful electrochemical extraction has been accomplished using electrochemical cells with lithium-intercalating electrodes, like lithium iron phosphate (LFP) and lithium manganese oxide (LMO), prepared in-lab. LFP is a common cathode material for solid-state lithium-ion batteries, meaning that an opportunity to use spent batteries for this application may exist if successful. The use of commercial LFP for the recovery of lithium from brine was investigated through analysis of aqueous electrochemical cell experiments using ion chromatography, inductively coupled plasma-mass spectrometry, and X-ray fluorescence. A two-step process in which lithium was extracted from simulated brine then released into recovery brine was used. In these experiments, commercial LFP was not able to recover a significant amount of lithium. This was likely due to the complications, including hydrophobicity and the presence of binders, caused by its manufacturing process.

South Dakota Mines
Dr. Brett Carlson