Transient Plane Source Method for Thermal Property Measurements of Metal Hydrides

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.