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Published on: August 17, 2016
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Transformation Kinetics of LiBH4-MgH2 for Hydrogen Storage
Ou Jin1,2, Yuanyuan Shang3, Xiaohui Huang2
1Institute for Applied Materials, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany.
Molecules (Basel, Switzerland)
|October 27, 2022
Summary
Adding 3TiCl3·AlCl3 to LiBH4-MgH2 reactive hydride composite improves hydrogen storage kinetics. The additive promotes MgB2 formation on TiB2 nanoparticles, enhancing dehydrogenation rates.
Area of Science:
- Materials Science
- Chemical Engineering
- Nanotechnology
Background:
- Reactive hydride composite (RHC) LiBH4-MgH2 is a promising hydrogen storage material.
- Limited application due to poor dehydrogenation kinetics of MgB2 formation.
- Additives can enhance hydrogen storage performance.
Purpose of the Study:
- Investigate the MgB2 growth process with 3TiCl3·AlCl3 additive.
- Understand the structural and kinetic effects of varying additive content.
- Optimize additive concentration for improved dehydrogenation kinetics.
Main Methods:
- Kinetic measurements
- X-ray diffraction (XRD)
- Advanced transmission electron microscopy (TEM)
- Johnson-Mehl-Avrami-Kolmogorov (JMAK) modeling
Main Results:
- MgB2 formation preferentially occurs on TiB2 nanoparticles.
- Reduced elastic strain energy at the MgB2-TiB2 interface (~4.7 × 10^7 J/m^3) compared to MgB2-Mg interface (~2.9 × 10^8 J/m^3).
- JMAK equation accurately models MgB2 growth kinetics.
- Shift in rate-controlling step from interface- to diffusion-controlled.
- Change in MgB2 morphology from bar- to platelet-like.
Conclusions:
- 3TiCl3·AlCl3 additive significantly enhances MgB2 nucleation and growth.
- Optimal additive content for best dehydrogenation kinetics is between 2.5 and 5 mol%.
- Understanding the interface effects and growth mechanisms is crucial for designing advanced hydrogen storage materials.
Keywords:
additivecrystallographyhydrogen storagephase transformationreactive hydride compositetransmission electron microscopyMore Related Videos
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