Sustainable selective extraction of lithium chloride from natural brine using a Li1-xMn2O4 ion pump

Abstract

The spontaneous electrochemical extraction of lithium chloride from natural brine of high altitude salt flats in Northwest Argentina and recovery in a dilute electrolyte is demonstrated in two experiments: i) a highly selective LiMn2O4 insertion cathode and polypyrrole anion selective anode (salt capturing) and ii) 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.