Development of a High-Throughput Apparatus for Measuring Thermal Conductivity and Creating Improved Energy Storage Materials

One of the barriers for the widespread inclusion of concentrating solar power (CSP) technologies for electric power generation is the lack of a suitable thermal energy storage (TES) technology to compensate for the intermittency issues of CSP. Inorganic salts can be used as phase-change materials for TES by taking advantage of their large heats of fusion. However, their low thermal conductivities, particularly in the solid state, hinder the efficient transfer of heat into and out of the salts. We are working to improve the thermal conductivity of alkali nitrate and nitrite salts by the addition of high-aspect-ratio, high-thermal-conductivity micro- and nanoparticles. To this end, we are developing an apparatus for rapid high-throughput measurements of the thermal properties of the composite materials. We will report on the validation of the apparatus and present initial results on the effect of the addition of silicon carbide whiskers on the thermal conductivity of an inorganic phase-change salt at room temperature.