Sugar alcohol phase change materials for low-to-medium temperature thermal energy storage: A comprehensive review

The adoption of appropriate phase change materials (PCMs) is deemed to be the primary step during the course of application of latent heat storage technology. As a class of potential candidates, sugar alcohols are suitable for latent heat storage over medium temperature range (80-230 degrees C). The present work attempts to provide a comprehensive overview on the phase change behaviors, transport properties, thermal stability, charging/dis-charging performance and application status of sugar alcohols based on adequate amount of available in-vestigations. Special attention is paid to their peculiar crystallization behaviors including supercooling, non -crystallization and cold-crystallization. In particular, the intrinsic mechanisms responsible for the above be-haviors and properties are fully discussed, and some suitable techniques for alternating such behaviors/prop-erties have been proposed accordingly. The specific advantages like high heat storage density and challenges such as poor thermal endurance are completely summarized for sugar alcohols. Furthermore, the potential application scenarios associated with long-term heat storage and controllable heat retrieval are put forward on the basis of the particular properties. Future studies with emphasis on the underlying fundamentals of crystal-lization and chemical reactions concerned with thermal stability are suggested. This review aims at building a benchmark database on the key information of sugar alcohol PCMs, thus to help deeply understand their properties. It can also provide useful guidelines to facilitate the large-scale utilization of sugar alcohols in solar thermal energy harvesting and industrial waste heat recovery.