Electrochemical behavior of Li+, Mg2+, Na+ and K+ in LiFePO4/ FePO4 structures

Lithium versus Mono/Polyvalent Ion Intercalation: Hybrid Metal Ion Systems for Energy Storage

“…The different intercalation ability of various metal ions to LiFePO 4 has been verified by CV and chronopotentiometry studies in different aqueous electrolytes ,,. It has been established that the metal ions intercalation ability into FePO 4 olivine follows the sequence Li + ≫Na + >K + >Mg 2+ ( ion‐sieve effect ), while their deintercalation ability from LiFePO 4 show a reverse sequence, Li + <Na + <K + <Mg 2+ ,,.…”

“…The different intercalation ability of various metal ions to LiFePO 4 has been verified by CV and chronopotentiometry studies in different aqueous electrolytes ,,. It has been established that the metal ions intercalation ability into FePO 4 olivine follows the sequence Li + ≫Na + >K + >Mg 2+ ( ion‐sieve effect ), while their deintercalation ability from LiFePO 4 show a reverse sequence, Li + <Na + <K + <Mg 2+ ,,. Moreover, the redox potentials for the intercalation of individual ions into FePO 4 have been found to differ significantly (for instance, the negative reduction potentials increases in the order Li + <Na + <Mg 2+ ) which allows an effective Li + separation from the other metal ions by manipulating the cell voltage ,,.…”

Highly Selective and Pollution‐Free Electrochemical Extraction of Lithium by a Polyaniline/LixMn2O4 Cell

“…In addition to thesem ethods, electrochemical recovery of Li + ions from aqueous solution has also attracted considerable attention.I nt he early 1990s, Kanoh et al first reported as elective electrochemical extraction of Li + ions from aP t/l-MnO 2 cell, in which Li + ions can selectively insert into as pinel l-MnO 2 electrode with oxygen and hydrogen on aP te lectrode. [12] In recent years, an umber of studies have been conductedo nt he selective extraction of Li + ions from aL i x FePO 4 electrode; [13][14][15][16][17] however,t he co-insertion of Na + and Mg 2 + ions into the FePO 4 lattice remains ap roblem for its practical application.V ery recently,s everal research groups reported highly efficient electrochemical recovery of Li + ions through the use of a l-MnO 2 positivee lectrode and ac hloride-capturing negative electrode (such as Ag and Zn). [18][19][20][21] Although these electrochemical cells can avoid the co-insertion of interfering Na + ,M g 2 + ,K + ,C a 2 + ,a nd other cations,t hey suffer from rapid capacity decay owing to the poor reversibility of the chloride-capturing negative electrodes upon use for the electrochemical uptake of chloride ions.…”

Electrochemical Methods for Lithium Recovery: A Comprehensive and Critical Review

“…A similar study was extended to Na + and K + . [ 73 ] The authors observed that in a cyclic voltammetry using a Na + solution, the cathodic peak moved 400 mV more negative and the anodic peak split in two. However, in a K + solution, they did not observe any peak, suggesting that the intercalation of Na + is possible, but more hindered than that of Li + , contrary to that of K + , which does not happen.…”

“…The division of the electrochemical cell into two slots by the introduction of an anion exchange membrane with monovalent selective permeability permits the utilization of the spinel Li 1‐ x Mn 2 O 4 or LiFePO 4 as counter electrode [ 64,72,73,77 ] as well as Zn metal [ 60 ] or activated carbon with a high specific area ( Figures 3 and ). [ 61 ] All these systems have in common that the Li intercalation is compensated by the transfer of anions, mainly Cl − , through the membrane.…”