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Hydrogen dynamics in complex hydrides

English title Hydrogen dynamics in complex hydrides
Applicant Remhof Arndt
Number 134442
Funding scheme Project funding (Div. I-III)
Research institution Mobilität, Energie und Umwelt Empa
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Condensed Matter Physics
Start/End 01.04.2011 - 31.03.2012
Approved amount 60'884.00
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Keywords (5)

hydrogen storage materials; ionic mobility; Hydrogen Storage; Complex Hydrides; Hydrogen Dynamics

Lay Summary (English)

Lead
Lay summary

Due to its large hydrogen content of 18 mass% H2 and due to its hydrogen sorption reversibility,  LiBH4, is one of the most studied complex hydrides so far. At ambient conditions, it forms an ionic crystal, consisting of Li+ and BH4- ions. It undergoes a structural phase transition from the low temperature (LT) orthorhombic phase to the high temperature (HT) hexagonal phase at 383K Triggered by the phase transition the ion conductivity increases by almost three orders of magnitude from 5×10-6 S/cm to 2×10-3 S/cm. Stabilization of the HT phase of this compound by addition of lithium halides results in an enhanced conductivity also at room temperature.

Up to now, the origin of the phase transition, and therefore the role of the halides as stabilizing agents are not understood. Also the influence of the rapid localized motion of the BH4 anion on the Li-conductivity is not known so far. We propose to investigate the effect of lithium halides on the example of LiI on the hydrogen dynamics and on the thermodynamic properties of LiBH4

In the continuation of the ongoing project we investigate the hydrogen dynamics in halide stabilized LiBH4 with respect to potential applications as solid state electrolytes.

 


Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Mobility and dynamics in the complex hydrides LiAlH4 and LiBH4
Borgschulte A, Jain A, Ramirez-Cuesta AJ, Martelli P, Remhof A, Friedrichs O, Gremaud R, Zuttel A (2011), Mobility and dynamics in the complex hydrides LiAlH4 and LiBH4, in FARADAY DISCUSSIONS, 151, 213-230.
High-pressure and high-temperature x-ray diffraction cell for combined pressure, composition, and temperature measurements of hydrides
Mauron Philippe, Bielmann Michael, Remhof Arndt, Züttel Andreas (2011), High-pressure and high-temperature x-ray diffraction cell for combined pressure, composition, and temperature measurements of hydrides, in Review of Scientific Instruments, 82, 065108-1-065108-7.
Rotational Motion in LiBH4/LiI Solid Solutions
Martelli P, Remhof A, Borgschulte A, Ackermann R, Strassle T, Embs JP, Ernst M, Matsuo M, Orimo SI, Zuttel A (2011), Rotational Motion in LiBH4/LiI Solid Solutions, in JOURNAL OF PHYSICAL CHEMISTRY A, 115(21), 5329-5334.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Perspectives in Terahertz spectroscopy with neutrons 29.11.2011 Helmholtzzentrum für Materialien und Energie, Berlin, Germany
Public defence of the thesis 16.11.2011 Fribourg, Switzerland
Empa PHD Symposium 18.10.2011 Empa, St Gallen, switzerland
JUM@P '11: Joint Users' Meeting at PSI 2011 15.09.2011 PSI, Villigen, Switzerland
5th European Conference on Neutron Scattering 17.07.2011 Prague, Czech Republic
Gordon Research Conference, Hydrogen-Metal Systems 17.07.2011 Stonehill College, North Easton USA
27th One-Day-Symposium Electrochemistry Laboratory 11.05.2011 PSI, Villigen, Switzerland
Faraday Discussion 151: Hydrogen Storage Materials 18.04.2011 Rutherford Lab, Didcot, UK


Self-organised

Title Date Place
6th International Symposium Hydrogen & Energy 22.01.2012 Stoos, Switzerland

Communication with the public

Communication Title Media Place Year
Talks/events/exhibitions Hydrogen Dynamics in Complex Hydrides - public PhD defense Western Switzerland 16.11.2011

Associated projects

Number Title Start Funding scheme
119972 Hydrogen dynamics in complex hydrides 01.04.2008 Project funding (Div. I-III)

Abstract

We apply for the continuation of the project “Hydrogen Dynamics in Complex Hydrides”, project number SNF 200021-119972/1 for another 12 month. In the continuation of the ongoing project we propose to investigate the hydrogen dynamics in halide stabilized LiBH4 with respect to potential applications as solid state electrolytes. The continuation of the project allows the successful termination of the PhD work of Pascal Martelli.Due to its large hydrogen content of 18 mass% H2 and due to its hydrogen sorption reversibility, LiBH4, is one of the most studied complex hydrides so far. At ambient conditions, it forms an ionic crystal, consisting of Li+ and BH4- ions. It undergoes a structural phase transition from the low temperature (LT) orthorhombic phase to the high temperature (HT) hexagonal phase at 383K Triggered by the phase transition the ion conductivity increases by almost three orders of magnitude from 5?10-6 S/cm to 2?10-3 S/cm. Stabilization of the HT phase of this compound by addition of lithium halides results in an enhanced conductivity also at room temperature. Up to now, the origin of the phase transition, and therefore the role of the halides as stabilizing agents are not understood. Also the influence of the rapid localized motion of the BH4 anion on the Li-conductivity is not known so far. We propose to investigate the effect of lithium halides on the example of LiI on the hydrogen dynamics and on the thermodynamic properties of LiBH4
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