Lithium Isotope Effects in Cation Exchange Chromatography of Lithium Lactate in Water-Dimethyl Sulfoxide and Water-Acetone Mixed Solvent Media

1993 ◽  
Vol 48 (7) ◽  
pp. 811-818
Author(s):  
Takao Oi ◽  
Akiko Kondoh ◽  
Etsuko Ohno ◽  
Morikazu Hosoe
Keyword(s):  
Dimethyl Sulfoxide ◽  
Mixed Solvent ◽  
Isotope Effects ◽  
Isotope Separation ◽  
Lithium Ion ◽  
External Solution ◽  
Exchange Chromatography ◽  
Lithium Isotope ◽  
Isotope Distributions ◽  
Lithium Lactate

Abstract Lithium isotope separation by ion exchange displacement chromatography of lithium lactate in water-dimethyl sulfoxide (DMSO) and water-acetone mixed solvent media at 25 °C was explored. In both the water-DMSO and water-acetone system, the single stage isotope separation factor (S) was a convex function of the mixing ratio of the solvents in the external solution phase; S had its maximum value of 1.00254 at water: DMSO = 25:75 v/v and 1.00182 at water: acetone = 75:25 v/v. Strong correlations of S with solvent partitions between the solution and the exchanger phases were found in both systems, which was qualitatively explainable by considering the lithium isotope distributions between the two phases based on the fundamental lithium isotope effects and the relative affinities of water, DMSO and acetone towards the lithium ion.

Temperature Dependence of Lithium Isotope Effects in Ion Exchange Electromigration

1987 ◽  
Vol 42 (7) ◽  
pp. 709-712
Author(s):  
Yasuhiko Fujii ◽  
Morikazu Hosoe ◽  
Okamoto Makoto
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Isotope Effects ◽  
Isotope Separation ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Separation Coefficient ◽  
Lithium Isotope ◽  
Increasing Temperature ◽  
Exchange Membrane

The isotope separation coefficient of lithium electromigration through a cation exchange membrane is determined at 6, 11, 20 and 40 °C . It is found that this coefficient increases with temperature while the slope of the isotope distribution in the band decreases with increasing temperature. These tendencies are opposite to those usually observed in ion exchange chromatography.

Lithium Isotope Effect Accompanying Electrochemical Intercalation of Lithium into Graphite

2003 ◽  
Vol 58 (5-6) ◽  
pp. 306-312 ◽  
Author(s):  
Satoshi Yanase ◽  
Wakana Hayama ◽  
Takao Oi
Keyword(s):  
Isotope Effect ◽  
Separation Factor ◽  
Early Stage ◽  
Isotope Separation ◽  
Ethylene Carbonate ◽  
Lithium Ion ◽  
Lithium Isotope ◽  
Mixed Solution ◽  
Electrochemical Intercalation ◽  
Graphite Intercalation

Lithium has been electrochemically intercalated from a 1:2 (v/v) mixed solution of ethylene carbonate (EC) and methylethyl carbonate (MEC) containing 1 M LiClO4 into graphite, and the lithium isotope fractionation accompanying the intercalation was observed. The lighter isotope was preferentially fractionated into graphite. The single-stage lithium isotope separation factor ranged from 1.007 to 1.025 at 25 °C and depended little on the mole ratio of lithium to carbon of the lithium-graphite intercalation compounds (Li-GIC) formed. The separation factor inceased with the relative content of lithium. This dependence seems consistent with the existence of an equilibrium isotope effect between the solvated lithium ion in the EC/MEC electrolyte solution and the lithium in graphite, and with the formation of a solid electrolyte interfaces on graphite at the early stage of intercalation.

Lithium Isotope Effect Accompanying Electrochemical Insertion of Lithium into Liquid Gallium

2010 ◽  
Vol 65 (5) ◽  
pp. 461-467 ◽  
Author(s):  
Keita Zenzai ◽  
Ayaka Yasui ◽  
Satoshi Yanase ◽  
Takao Oi
Keyword(s):  
Isotope Effect ◽  
Isotope Effects ◽  
Isotope Separation ◽  
Ethylene Carbonate ◽  
Quantitative Agreement ◽  
Liquid Gallium ◽  
Molecular Orbital Calculations ◽  
Lithium Isotope ◽  
Mixed Solution ◽  
Separation Factors

Lithium was electrochemically inserted from a 1 : 2 (v/v) mixed solution of ethylene carbonate (EC) and methylethyl carbonate (MEC) containing 1M LiClO4 into liquid gallium to observe lithium isotope effects accompanying the insertion. It was observed that the lighter isotope 6Li was preferentially fractionated into liquid gallium with the single-stage lithium isotope separation factors S, ranging from 1.005 to 1.031 at 50 °C and 1.003 to 1.024 at 25 °C. The lithium isotope effects estimated by molecular orbital calculations at the B3LYP/6-311G(d) level of theory agreed qualitatively with those of the experiments, but the quantitative agreement of the two was not satisfactory

Engineering study on lithium isotope separation by ion exchange chromatography

2021 ◽  
Vol 168 ◽  
pp. 112478
Author(s):  
Tatsuya Suzuki ◽  
Minghui Zhang ◽  
Masao Nomura ◽  
Takehiko Tsukahara ◽  
Masahiro Tanaka
Keyword(s):  
Ion Exchange ◽  
Isotope Separation ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Lithium Isotope ◽  
Engineering Study

Observation of Lithium Isotope Effects Accompanying Electrochemical Release from Lithium Cobalt Oxide

2013 ◽  
Vol 68 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
Yuta Takami ◽  
Satoshi Yanase ◽  
Takao Oi
Keyword(s):  
Cobalt Oxide ◽  
Electrolyte Solution ◽  
Isotope Composition ◽  
Isotope Effects ◽  
Lithium Ion ◽  
Isotopic Ratios ◽  
Lithium Cobalt Oxide ◽  
Lithium Isotope ◽  
Organic Electrolyte Solution ◽  
Lithium Cobalt

Change in the lithium isotope composition in a lithium cobalt oxide (LiCoO2) cathode for lithium ion secondary batteries accompanying the electrochemical lithium release from the cathode into an organic electrolyte solution was observed. The 7Li/6Li isotopic ratios of the electrodes after the release of 37.2 to 55:4% lithium were 1.018 to 1.033 times smaller than that before the release. This means that the heavier isotope, 7Li, is preferentially transferred to the electrolyte solution.

Ab initio Molecular Orbital Calculations of Reduced Partition Function Ratios of Hydrated Lithium Ions in Ion Exchange Systems

2001 ◽  
Vol 56 (3-4) ◽  
pp. 297-306 ◽  
Author(s):  
Satoshi Yanase ◽  
Takao Oi
Keyword(s):  
Partition Function ◽  
Ion Exchange ◽  
Molecular Orbital ◽  
Isotope Effects ◽  
Isotope Separation ◽  
Water Molecules ◽  
Molecular Orbital Calculations ◽  
Lithium Isotope ◽  
Lithium Ions ◽  
Additional Water

Abstract Molecular orbital (MO) calculations at the HF/6-31G(d) level were carried out for the aquolithium ions, Li+(H2O)n (n = 3, 4, 5, 6, 8, 10 and 12) and the aquolithium ions interacting with the methyl sul­fonate ion (MeS-), Li+MeS-(H2O)n (n = 0, 3,4, 5, 6, 7, 8 and 10) which were, respectively, intended to be substitutes for lithium species in the solution and resin phases of ion exchange systems for lithium isotope separation. For each of the species considered, at least one optimized structure with no negative frequency was obtained, and the 7Li-to-6Li isotopic reduced partition function ratio (RPFR) was esti­mated for the optimized structure. The solvation number in the primary solvation sphere was four, both in the solution and resin phases; three waters and MeS" formed the primary solvation sphere in the res­ in phase. Additional water molecules moved off to the secondary solvation sphere. It was found that consideration on the primary solvation sphere alone was insufficient for estimations of reduced parti­tion function ratios of aquolithium ions. Although the agreement between the experimentally obtained lithium isotope fractionation and the calculated results is not satisfactory, it is pointed out that the HF/6-31 G(d) level of the theory is usable for elucidation of lithium isotope effects in aqueous ion exchange systems.

scholarly journals Electromigration Separation of Lithium Isotopes: The Effect of Electrode Solutions

2022 ◽  
Author(s):  
Ciming Wang ◽  
Pengrui Zhang ◽  
Chaochi Huang ◽  
Qian Zhang ◽  
Huiqun Ju ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Isotope Separation ◽  
Lithium Ion ◽  
Nuclear Industry ◽  
Lithium Isotope ◽  
Lithium Ions ◽  
Lithium Isotopes ◽  
Electrode Solutions ◽  
Organic Solutions

Abstract Both lithium-6 and lithium-7 with high abundance are indispensable materials in nuclear industry. Here, an aqueous solution│organic solution│aqueous solution system was fabricated to separate lithium isotopes. The effects of species and concentration of electrolytes in the electrode solutions on the lithium ions migration and lithium isotope separation with different voltages and migration time was studied. It was found that lithium-7 was enriched in aqueous solutions on both sides at 0 V and 2 V, while lithium-7 was enriched in anode solution and lithium-6 was enriched in cathode solution at 16 V. The weakening stability of the chelate consisted of crown ether and lithium ion with increasing voltage was believed to the possible reason. Meanwhile, the variation of electrolyte in electrode solution led to notable changes in migration ratio of lithium ions and lithium isotope separation effect, which can be attributed to the different degree of both ionization and hydrolysis for various electrolytes in aqueous solutions and the different ability of H+ and NH4+ to replace Li+ of chelate in organic solutions. This work is of great significance for the selection of electrode solutions in electromigration separation of lithium isotopes and even other electrochemical systems.

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