Thermal conductivity measurements of copper-coated metal hydrides (LaNi5, Ca0.6Mm0.4Ni5, and LaNi4.75Al0.25) for use in metal hydride hydrogen compression systems

Metal hydrides are promising hydrogen storage materials with potential for practical use in a passenger car. To be a viable hydrogen storage option, metal hydride heat transfer behavior must be well understood and accounted for. As such, the thermal properties of the metal hydride are measured and compiled to assess this behavior. These properties include thermal conductivity, specific heat, and thermal diffusivity. The transient plane source (TPS) method was selected primarily due to a high level of versatility, including customization for high pressure hydrogen environments. To perform this measurement, a TPS 2500 S thermal property analyzer by the Hot Disk Company was employed. To understand the measurement and analysis process of the TPS method, two different sample materials were evaluated at ambient conditions. These samples included a stainless steel pellet and an inactivated (non-pyrophoric) metal hydride pellet. Thermal conductivity and thermal diffusivity of these samples were measured using the TPS method. The thermal property measurements are compared to the data available in the literature (stainless steel) and the data obtained using laser flash method (metal hydride). The improvements needed to successfully implement the TPS method are discussed in detail.

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Metal Hydride-Based Composite Materials with Improved Thermal Conductivity and Dimensional Stability Properties

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.72.170 ◽

2010 ◽

Vol 72 ◽

pp. 170-175 ◽

Cited By ~ 4

Author(s):

Marzia Pentimalli ◽

Andrea Frazzica ◽

Angelo Freni ◽

Enrico Imperi ◽

Franco Padella

Keyword(s):

Experimental Data ◽

Thermal Conductivity ◽

Composite Material ◽

Metal Hydride ◽

Linear Increase ◽

Silica Matrix ◽

Conductivity Measurements ◽

Active Metal ◽

Composition Optimization

To address the issues of poor thermal conductivity and fragmentation of metal hydride particles undergoing hydriding/dehydriding reactions, a metal hydride-based composite material was developed. The active metal phase was embedded in a silica matrix and a graphite filler was incorporated by ball milling. A set of compact pellet samples at different composition were prepared and tested. Experimental data obtained from the thermal conductivity measurements shown that using powder graphite produced a quite linear increase in the thermal conductivity of the metal hydride – silica composite. Ongoing studies include composition optimization as well as long-term testing upon cycling of such metal hydride composites to evaluate their potentiality in technological hydrogen storage applications.

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Thermal Conductivity Measurements of Metal Hydride Compacts Developed for High-Power Reactors

Journal of Thermophysics and Heat Transfer ◽

10.2514/2.6332 ◽

1998 ◽

Vol 12 (2) ◽

pp. 132-137 ◽

Cited By ~ 22

Author(s):

George Lloyd ◽

Kwang J. Kim ◽

Arsalan Razani ◽

K. Thomas Feldman

Keyword(s):

Thermal Conductivity ◽

High Power ◽

Metal Hydride ◽

Conductivity Measurements

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Physics based models for metal hydride particle morphology, distribution, and effective thermal conductivity

MRS Proceedings ◽

10.1557/proc-1172-t09-05 ◽

2009 ◽

Vol 1172 ◽

Cited By ~ 1

Author(s):

Kyle Christopher Smith ◽

Timothy Fisher

Keyword(s):

Thermal Conductivity ◽

Particle Size ◽

Effective Thermal Conductivity ◽

Metal Hydride ◽

Metal Hydrides ◽

Particle Morphology ◽

Particle Packing ◽

Interparticle Contact ◽

Storage Media ◽

Particle Size And Shape

AbstractThis paper describes a modeling approach to target aspects of heat conduction in metal hydride powders that are essential to metal hydrides as viable H2storage media, including particle morphology distribution, size distribution, particle packing properties at specified solid fraction, and effective thermal conductivity. An isotropic fracture model is presented that replicates features of particle size and shape distributions observed experimentally. The discrete element method is used to simulate evolution of metal hydride particle contact networks during quasi-static consolidation of decrepitated metal hydride powders. Finally, the effective thermal conductivity of such a powder is modeled assuming that contact conductance is the same for each interparticle contact.

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