Typical Applications and Flame‐Retardant Strategies for Organic Phase‐Change Materials

ABSTRACT This study begins by exploring the typical practical applications of phase‐change materials (PCMs) in various industries, highlighting their importance in energy storage, temperature regulation, and thermal management. It then emphasizes the necessity of flame‐retardant functionalization tailored to the specific application scenarios of PCMs, especially considering their use in safety‐critical environments such as electronics, automotive, and construction. The classic characterization methods for assessing the flame‐retardant properties of PCM are introduced in detail, including the limiting oxygen index, the vertical burning test, and the cone calorimeter, which are widely recognized standards in material safety testing. Additionally, newly developed methods for evaluating combustion safety are discussed, such as direct combustion tests, candle combustion experiments, and back temperature response, which offer a more comprehensive understanding of the material's fire resistance. Following this, this study provides a thorough summary and categorization of the flame‐retardant strategies used in PCMs, divided into four main approaches: (1) incorporation of external flame retardants, (2) use of flame‐retardant microcapsules, (3) development of flame‐retardant support materials, and (4) creation of intrinsic flame‐retardant PCMs. Each strategy is critically analyzed in terms of effectiveness, applicability, and potential challenges. Lastly, the conclusion provides an overview of the current state of flame‐retardant PCMs, offering insights into future development directions, including the pursuit of more sustainable and efficient flame‐retardant solutions, as well as prospects for their broader adoption in various industries.