Advanced multifunctional composite phase change materials based on photo-responsive materials

Phase change materials (PCMs) with excellent energy storage capacity and approximately constant temperature during the phase transition process can absorb and store thermal energy from their surroundings and release it when needed, thereby improving the energy utilization efficiency. However, thermal energy storage requires the temperature of PCMs above their melting points by passive heat absorption, which lacks of proactive control and has great limitations in actual applications. Emerging photo-responsive materials bring some new potentials to the PCM field owing to their distinct response to light and other special features, which can meet the specific requirements such as photothermal conversion in extreme environments. Meanwhile, photo-responsive materials have integrated some new functions into PCMs other than thermal energy storage. However, a comprehensive overview of multifunctional photo-responsive composite PCMs is still missing. Herein, we provide a comprehensive review of the state-of-the-art applications of photo-responsive PCMs. The mechanisms, current developments and further perspectives concerning multifunctional photo-responsive composite PCMs are also highlighted.