Compatibility of container materials with peritectic phase change material for high-temperature thermal energy storage

Compatibility of storage and container materials is a well-known problem for high-temperature thermal energy storage (TES) technology, which often limits the use of the most economic and best performing materials. Peritectic phase change materials (PCMs) were recently demonstrated as promising TES materials that provide an alternative for molten salts and metallic alloys PCMs. However, unlike molten salts and alloys, peritectic PCMs have not yet been explored in terms of corrosion. This work presents the first compatibility study between Li4(OH)3Br peritectic and common construction materials such as carbon steel and stainless steel 316. Mass gain, XRD, and EDX-SEM surface as well as cross-section analyses reveal that the studied peritectic is recommended for long-term use with carbon steel under air atmosphere and is fully compatible with SS316 under both air and argon atmosphere. Both experimental observations as well as chemical reactions analysis suggest that carbon steel should be used under air rather than inert atmosphere to maximize its compatibility with Li4(OH)3Br peritectic.