Review of research progress on corrosion and anti-corrosion of phase change materials in thermal energy storage systems

Abstract

Using phase change material (PCM) as the energy storage medium and applying it in a latent heat energy storage system has become an important way of new energy application. PCM has been widely used in various thermal storage applications around the world due to its high storage density, wide range of melting and solidification temperatures, and good economic performance. Its application scope includes solar energy storage systems, cold chain logistics, the construction industry, and so on. However, PCM is usually encapsulated in a container, and its corrosion directly affects the life of the container and the performance of the latent heat storage system. Therefore, the compatibility between various PCM and packaging materials has become a key problem in the practical application of PCM. This paper reviews the phase change materials (organic, inorganic, and eutectic) as a storage medium in the corrosion problems in the application of latent heat storage system, comparing the common PCM for several common metal materials (aluminum, copper, carbon steel, stainless steel) corrosion behavior, found that stainless steel and most of the phase change materials can show the excellent compatibility. Its corrosion rate is the lowest compared with other metal materials. However, aluminum only has good corrosion resistance to some PCM (mirabilite and magnesium nitrate hexahydrate, etc.), and its corrosion rate is higher when it is in contact with most PCM. It needs to be determined according to the actual situation when it is used. The corrosion rate and recommended use degree of some PCM in contact with metal materials are also listed. In addition, this paper also summarizes the corrosion protection problems of PCM through three ways of corrosion inhibitor, packaging, and coating, which provides an effective basis for future corrosion research and solving the corrosion protection problems. Because of the wide variety of PCM, more research is needed on the corresponding corrosive problem. Therefore, a corrosion test should be added as part of the experimental paper in the preparation of various phase change materials. At present, most corrosion experiments are carried out on metal materials, and the corrosion behavior of plastics as packaging materials can also be studied. It is also a research direction to select appropriate additives to solve the corrosion problem of phase change materials.