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09:36
In Situ Lithiated Reference Electrode: Four Electrode Design for In-operando Impedance Spectroscopy
Published on: September 12, 2018
Electrochemical isotope effect and lithium isotope separation
Jay R Black1, Grant Umeda, Bruce Dunn
1Institute for Geophysics and Planetary Physics, University of California, Los Angeles, California 90095, USA.
Journal of the American Chemical Society
|July 8, 2009
Summary
Electrodeposition of lithium from propylene carbonate solutions yields isotopically light lithium metal. The isotopic effect magnitude depends on applied overpotential, being largest near equilibrium conditions.
Area of Science:
- Electrochemistry
- Isotope Geochemistry
- Materials Science
Background:
- Electrochemical deposition is a key process for producing pure metals.
- Isotopic fractionation in electrochemical systems is not fully understood.
- Lithium's unique properties make its isotopic behavior of interest.
Purpose of the Study:
- To investigate the electrochemical isotopic effect during lithium deposition.
- To determine the factors controlling isotopic fractionation in this system.
- To compare experimental results with theoretical predictions.
Main Methods:
- Electrochemical deposition of lithium from propylene carbonate solutions.
- Measurement of isotopic composition of deposited lithium.
- Varying applied overpotential to study its effect on fractionation.
- Calculation of partition function ratios for lithium complexes and metal.
Main Results:
- A significant electrochemical isotopic effect was observed, producing isotopically light lithium.
- The extent of isotopic fractionation was directly controlled by the applied overpotential.
- Maximum fractionation occurred at overpotentials closest to electrochemical equilibrium.
- Theoretical calculations of partition function ratios aligned well with experimental findings.
Conclusions:
- Electrochemical deposition of lithium exhibits a large isotopic effect.
- Overpotential is a critical parameter governing isotopic fractionation during lithium electrodeposition.
- Theoretical models support the experimental observations of equilibrium fractionation.
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