Miniaturized measurement system of effective thermal conductivity for hydrogen storage materials

A miniaturized measurement cell of effective thermal conductivity (k_e) with volume of 15 ml was developed through numerical simulation-aided design. This system has a simplified configuration similar to a transient hotwire system, and is based on an absolute steady state method. Numerical simulation of heat transfer revealed that k_e measurement up to 10 W/m K is possible. Various aspects of this system, such as gas pressure and different filling gas, were verified using LaNi5 as a reference material, indicating that this system can measure the k_e of metal hydride beds with acceptable accuracy. This system was applied to measure the k_e of pure and Pt-decorated multi-walled carbon nanotubes (MWCNTs), MgH2 powder, and compressed MgH2 with heat transfer matrix. The measured values of k_e agreed closely with the results reported in previous works.