Thermal energy storage (TES) has been identified as a breakthrough concept in development of renewable technologies. However, the main challenges are related to the development of competitive heat storage materials. Despite the number of studies on heat storage materials, the determination of new alternatives for next generation technologies is still open. In this regard, this paper presents the results of an experimental study of the physical, thermal and mechanical properties of SiC-doped ceramics as potential materials for TES applications. Two kinds of SiC additives (high and low densities) were incorporated with different percentages into the clay matrix in order to produce ceramics via the extrusion process. The addition of low-density SiC (true density 3.16 g cm⁻³) led to the increasing of porosity with large pore sizes and the decreasing of bulk density. Therefore, the thermal and mechanical properties are decreased up to − 50% for flexural strength and − 15% for thermal conductivity when 20 mass% of low-density SiC was used. On the other hand, when high-density SiC (true density 3.42 g cm⁻³) was used, properties of the clay ceramic were strongly improved: i.e., increase in the bulk density, decrease in the porosity, increase in the thermal conductivity and increase in the flexural strength. The best material was found with the addition of 20 mass% of high-density SiC which had a thermal conductivity of 1 W m⁻¹ K⁻¹, a specific heat capacity of 0.62 kJ kg⁻¹ K⁻¹ and a mechanical strength of 19.6 MPa. It also showed a high thermal stability after 20 successive heating/cooling cycles. Hence, this study provided a useful insight into how the SiC modified the microstructure and properties of fired clay ceramics. Thus, the current results suggest that clay ceramics with high-density SiC addition are promising materials for thermal energy storage applications.

中文翻译：

---

蓄热用粘土/ SiC陶瓷的物理，热和机械性能研究

热能存储（TES）已被确定为可再生技术开发中的突破性概念。但是，主要挑战与竞争性储热材料的开发有关。尽管对储热材料的研究很多，但下一代技术的新替代方法的确定仍在公开中。在这方面，本文介绍了作为TES应用潜在材料的SiC掺杂陶瓷的物理，热和机械性能的实验研究结果。两种SiC添加剂（高密度和低密度）以不同百分比掺入粘土基质中，以便通过挤压工艺生产陶瓷。添加低密度SiC（真密度3.16 g cm ^-3）导致大孔径时孔隙率增加而堆积密度降低。因此，当使用20质量％的低密度SiC时，抗弯强度的热和机械性能降低至-50％，热导率降低至-15％。另一方面，当使用高密度SiC（真实密度为3.42 g cm ^-3）时，粘土陶瓷的性能得到了极大的改善：即，堆积密度的增加，孔隙率的降低，热导率的增加和增加抗弯强度。发现最好的材料是添加20质量％的高密度SiC，其导热系数为1 W m ^-1 K ^-1，比热容为0.62 kJ kg ^-1 K ^-1机械强度为19.6 MPa。在连续20个加热/冷却循环后，它还显示出高的热稳定性。因此，这项研究提供了有用的见解，以了解SiC如何改善煅烧粘土陶瓷的微观结构和性能。因此，目前的结果表明，添加高密度SiC的粘土陶瓷是用于热能存储应用的有前途的材料。