Exploration of Basalt Glasses as High-Temperature Sensible Heat Storage Materials

Thermal energy storage (TES) systems are a key technology that utilizes renewable energy and low-level thermal energy to ensure continuous and stable operation in concentrated solar power plants, family heating, and industrial waste heat recovery fields. It solves the intermittent problem of solar radiation and significantly improves energy efficiency and economic benefits. Three varieties of natural basalt ores have been selected, namely, intermediate, basic, and ultrabasic basalt, which have been prepared into basalt glasses by the melt-quenching method. The applicability of basalt glass to high-temperature heat storage applications is studied. In the present paper, the chemical composition and structure of basalt glasses have been determined. The effect of temperature and composition on key thermophysical properties such as density, heat capacity, thermal diffusion, thermal conductivity, and thermal expansion has been analyzed during a series of thermal cycles. It has been confirmed that basalt glass has extremely high heat storage performance and thermal stability, and its working temperature is as high as 1000 °C such that it can be used as a solar energy heat storage material.