What are the advantages of molten salt phase change materials compared to water?

Phase change materials have the ability to change their physical state within a certain temperature range. Taking the solid-liquid phase transition as an example, when heated to the melting temperature, a phase transition from the solid state to the liquid state occurs; during this melting process, the phase-change material absorbs and stores a large amount of latent heat ； When a phase-change material cools down, the heat stored in it must be released into the environment over a certain temperature range, resulting in an inverse phase change from liquid to solid state. In these two phase transition processes, the energy stored or released is called latent heat of phase change. When the physical state changes, the temperature of the material itself remains almost constant until the phase transition is complete, resulting in a wide temperature plateau. Although the temperature stays the same, the latent heat absorbed or released is quite large. Heat storage materials store heat by relying on changes in the temperature of the heat storage material; the heat release process does not occur at a constant temperature. Their low heat storage density results in large-sized storage devices, and the temperature difference with the surrounding environment leads to heat loss. As a result, heat cannot be stored for long periods of time, making them unsuitable for long-term, large-scale heat storage.

Melting salts can operate at high temperatures under normal pressure, while water can generally only function below 100 degrees Celsius

Processes that use molten salt for heating operate at very high temperatures, and steam or heat transfer oil cannot meet the temperature requirements. If given a choice, no company would prefer molten salt heating over steam or heat transfer oil