Flexible engineering of advanced phase change materials.

Liquid phase leakage, intrinsic rigidity, and easy brittle failure are the longstanding bottlenecks of phase change materials (PCMs) for thermal energy storage, which seriously hinder their widespread applications in advanced energy-efficient systems. Emerging flexible composite PCMs that are capable of enduring certain deformation and guaranteeing superior mutual contact with integrated devices are considered as a cutting-edge effective solution. Flexible PCMs-based thermal regulation technology can reallocate thermal energy and regulate the temperature within an optimal range. Currently, tireless efforts are devoted to the development of versatile flexible PCMs-based thermal regulation devices, and a big step forward has been taken. Herein, we systematically outline fabrication techniques, flexibility evaluation strategies, advanced functions and advances of flexible composite PCMs. Furthermore, existing challenges and future perspectives are provided in terms of flexible PCMs-based thermal regulation techniques. This insightful review aims to provide an in-depth understanding and constructive guidance of engineering advanced flexible multifunctional PCMs.