Sorption of atmospheric gases by bulk lithium metal

Abstract

Lithium conditioning of plasma facing components has enhanced the performance of several fusion devices. Elemental lithium will react with air during maintenance activities and with residual gases (H 2 O, CO, CO 2 ) in the vacuum vessel during operations. We have used a mass balance (microgram sensitivity) to measure the mass gain of lithium samples during exposure of a ~ 1 cm 2 surface to ambient and dry synthetic air. For ambient air, we found an initial mass gain of several mg/h declining to less than 1 mg/h after an hour and decreasing by an order of magnitude after 24 h. A 9 mg sample achieved a final mass gain corresponding to complete conversion to Li 2 CO 3 after 5 days. Exposure to dry air resulted in a 30 times lower initial rate of mass gain. The results have implications for the chemical state of lithium plasma facing surfaces and for safe handling of lithium coated components.

Design and measurement methods for a lithium vapor box similarity experiment

“…A study on sorption of atmospheric gases by bulk Li metal 24 measured mass gain rates in room temperature, artificial dry air of roughly 0.2 mg cm −2 h −1 .…”

“…The boxes have an internal surface area of 150 cm 2 . If 6 min elapses during transfer from the vacuum chamber to the glovebox and the gas is as dry as the artificial dry air (estimated at 3.3% relative humidity 24 ), then the mass gain per box is estimated at 3 mg. This is < 1% of the predicted Li efflux from the third box (Table I).…”

Dissociative Adsorption of H2S on Li(110) Surface Using Density Functional Theory Calculations and Car‐Parrinello Molecular Dynamics Simulations

“…Zavadil and Armstrong have made significant contribution to explore the chemistry of small molecules on lithium surface [49,50] . The work carried out to determine the rate of passivation of lithium metal with the exposure of environmental gases clearly advocates the high susceptibility of lithium towards these gases [51] . H 2 S reaction on the surface of lithium was studied long ago and characterized employing X‐ray photoelectron spectroscopy (XPS) [52] .…”

“…[49,50] The work carried out to determine the rate of passivation of lithium metal with the exposure of environmental gases clearly advocates the high susceptibility of lithium towards these gases. [51] H 2 S reaction on the surface of lithium was studied long ago and characterized employing X-ray photoelectron spectroscopy (XPS). [52] Results suggest that H 2 S undergoes SÀ H dissociation leading to the formation of sulphide layer of relatively small thickness, and spectroscopic data denies the presence of sulfhydryl (LiSH) on the Li surface.…”

Storage of Lithium Metal: The Role of the Native Passivation Layer for the Anode Interface Resistance in Solid State Batteries

“…Pilling and Bedworth found that it depends on the relative molar volume of a metal and the corresponding metal oxide if the metal oxide can form a covering and protective layer on the metal. 6,7 To classify different metal oxides, the Pilling-Bedworth ratio is calculated as follows: For a ratio smaller than one, the oxide film is unprotective, as it will be porous and/or cracked. Consequently, the oxidation reaction is not self-limiting and the thickness of the oxide film will increase steadily.…”