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Environmental barrier coating (EBC) materials that are resistant against molten calcia-magnesia-aluminosilicate (CMAS) corrosion are urgently required. Herein, multicomponent rare-earth (RE) disilicate ((Yb0.2Y0.2Lu0.2Sc0.2Gd0.2)2Si2O7, (5RE)2Si2O7) was investigated with regard to its CMAS interaction behavior at 1400 °C. Compared with the individual RE disilicates, the (5RE)2Si2O7 material exhibited improved resistance against CMAS attack. The dominant process involved in the interaction of (5RE)2Si2O7 with CMAS was reaction-recrystallization. A dense and continuous reaction layer protected the substrate from rapid corrosion at high temperatures. The results demonstrated that multicomponent strategy of RE species in disilicate can provide a new perspective in the development of promising EBC materials with improved corrosion resistance.

Solar air conditioning is an important approach to satisfy the high demand for cooling given the global energy situation. The application of phase-change materials (PCMs) in a thermal storage system is a way to address temporary power problems of solar air-conditioning systems. This paper reviews the selection, strengthening, and application of PCMs and containers in latent thermal storage system for solar air-conditioning systems. The optimization of PCM container geometry is summarized and analyzed. The hybrid enhancement methods for PCMs and containers and the cost assessment of latent thermal storage system are discussed. The more effective heat transfer enhancement using PCMs was found to mainly involve micro-nano additives. Combinations of fins and nanoadditives, nanoparticles, and metal foam are the main hybrid strengthening method. However, the thermal storage effect of hybrid strengthening is not necessarily better than single strengthening. At the same time, the latent thermal storage unit has less application in the field of solar airconditioning systems, especially regarding heat recovery, because of its cost and thermal storage time. The integration of latent thermal storage units and solar air-conditioning components, economic analysis of improvement technology, and quantitative studies on hybrid improvement are potential research directions in the future.

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