Review-Paper: Sugar Alcohol Based Phase Change Materials: Progress and Challenges in Medium to High Temperature Heat Storage

The present study analyses the potential of sugar alcohols as latent heat storage materials for applications in the medium to high temperature range (60-200 °C). In view of the increasing share of volatile renewable energies, thermal energy storage, especially on the basis of phase change materials (PCM), represents a promising solution. Sugar alcohols, including erythritol, xylitol, D-sorbitol and D-mannitol, are distinguished by their high melting enthalpies, optimal melting temperatures and advantageous polymorphic properties. The study systematically compares the thermophysical properties of the materials under varying heating rates and analyses eutectic mixtures to optimise melting behaviour and undercooling. Furthermore, the crystallisation triggering mechanisms (e.g. air injection, ultrasound, additives) and the rheological properties in the supercooled state are investigated. The findings demonstrate that the utilisation of appropriate mixtures facilitates stable supercooling and high cycle stability over an extended period, which is a pivotal consideration for seasonal heat storage. The combination of targeted sample preparation, mixing strategy and rheological control opens up new perspectives for sustainable thermal energy storage systems.