"Sustainable Electrochemical Extraction of Lithium Chloride from Natural Brine" by Ernesto J. Calvo (Thurs, 16 May 2019)
Sustainable Electrochemical Extraction of Lithium Chloride from Natural Brineby Prof. Ernesto J. Calvo, Universidad de Buenos Aires, Argentina
Thursday, 16 May 2019 @ 3 pm
ICMAB - Sala d'Actes Carles Miravitlles
The spontaneous electrochemical extraction of lithium chloride from natural brine of high altitude salt flats in northwest Argentina and recovery in a dilute electrolyte has been demonstrated in two experiments.
- A highly selective LiMn2O4 insertion cathode and polypyrrole anion selective anode (salt capturing).
- An LiMn2O4 anode and lithium deficient Li1-xMn2O4 cathode separated by anion selective membrane (selective ion exchange).
The entropy driven transfer of LiCl from concentrated brine to a dilute recovery electrolyte has been experimentally studied by ion pumping and the LiCl activity measured in natural brine.
The evolution of lithium chloride concentration in the recovery electrolyte has been followed by a lithium selective electrode, while the reactor total voltage and each electrode potential with respect to a Ag/AgCl; 3 M KCl reference electrode were continuously monitored by high impedance potential followers.
The effect of lithium chloride concentration in natural brine, applied current density and reactor geometry have been studied in scalling up the lithium chloride extracting reactor, while the extraction efficiency and charge capacity were evaluated.
A mathematical model for the reactor comprising the Nernst-Planck equation and the battery intercalation model has been developed. The model was solved using the finite element method under the COMSOL multiphysics environment in order to obtain the electrostatic potential and the ion currents and concentrations across the systems. Unlike the asymmetric LiMn2O4 /activated carbon supercapacitor, in the lithium extracting reactor the total LiCl concentration decreases in the extraction step and increases in the recovery step. A good agreement between the experimental and simulated potential difference vs. time at constant current validates the model of the reactor.
- V.C.E. Romero, M. Tagliazucchi, V. Flexer and E.J. Calvo, J. Electrochem. Soc., 165. (10), A2294-A2302, 2018).
- 2. F. Marchini, F.J. Williams, E.J. Calvo, J. Electrochem. Soc., 165,(14), A3292-A3298, (2018).
Hosted by Dino Tonti, Solid State Chemistry Group
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