The Electrochemical Extraction of Lithium from Seawater through the Lithiation and Delithiation of LiFePO4 Electrodes in a Flow Battery

With the rise of rechargeable electric devices and vehicles, the usage of lithium-ion (Li-ion)
batteries has expanded in the last decade. As things stand, the current lithium supply will be
unable to meet the growing demand. Currently, majority of lithium mined through evaporation of
brine pools, which is both geographically limited and time consuming. Therefore, alternative
lithium sources are being considered, specifically lithium extraction from seawater using
electrochemical intercalation. The use of electrochemical intercalation has been tested in batch
form on lab scale extensively, and shown to be an effective method in selectively separating
lithium. However, to implement this method on an industrial scale, an autonomous, flow process
must be considered. This experiment explores the use of a flow battery system with a naphion
membrane, and LiFePO4, as the active material, to electrochemically extract lithium from brines.
Preliminary experiments using a H-Cell, a batch version of the flow set-up, suggest the process
of delithiation and lithiation are successful in this configuration. The throughput and selectivity
for lithium are measured to determine the efficacy of the process. To improve the industrial
practicality of the process, alternative flow systems using a Li-selective ceramic membrane are
also being considered and tested, to improve the autonomy of the process.