Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Crown Street, L69 7ZD, Liverpool, UK.
Chem Soc Rev. 2018 Jun 5;47(11):4156-4175. doi: 10.1039/c8cs00099a.
Phase change materials (PCMs) allow the storage of large amounts of latent heat during phase transition. They have the potential to both increase the efficiency of renewable energies such as solar power through storage of excess energy, which can be used at times of peak demand; and to reduce overall energy demand through passive thermal regulation. 198.3 million tons of oil equivalent were used in the EU in 2013 for heating. However, bulk PCMs are not suitable for use without prior encapsulation. Encapsulation in a shell material provides benefits such as protection of the PCM from the external environment and increased specific surface area to improve heat transfer. This review highlights techniques for the encapsulation of both organic and inorganic PCMs, paying particular attention to nanoencapsulation (capsules with sizes <1 μm). We also provide insight on future research, which should focus on (i) the development of multifunctional shell materials to improve lifespan and thermal properties and (ii) advanced mass manufacturing techniques for the economically viable production of PCM capsules, making it possible to utilize waste heat in intelligent passive thermal regulation systems, employing controlled, "on demand" energy release/uptake.
相变材料（PCM）在相变过程中允许储存大量的潜热。它们有潜力通过储存多余的能量来提高太阳能等可再生能源的效率，这些能量可以在需求高峰期使用；并且通过被动热调节来降低整体能源需求。2013 年，欧盟用于供暖的石油当量为 1.983 亿吨。然而，大量的 PCM 在没有预先封装的情况下并不适合使用。封装在外壳材料中提供了一些好处，例如保护 PCM 免受外部环境的影响，并增加比表面积以改善传热。这篇综述强调了封装有机和无机 PCM 的技术，特别关注纳米封装（尺寸<1μm 的胶囊）。我们还提供了对未来研究的见解，未来的研究应侧重于：（i）开发多功能外壳材料，以提高使用寿命和热性能；以及（ii）先进的大规模制造技术，以经济可行的方式生产 PCM 胶囊，从而可以在智能被动热调节系统中利用余热，实现可控的、“按需”的能量释放/吸收。
