From low conductivity to high energy efficiency : The role of conductive polymers in phase change materials

Phase change materials (PCMs) face a significant obstacle in practical applications and energy efficiency due to their inherently low thermal conductivity. One promising solution to this limitation involves integrating conductive polymers (CPs) into PCMs. This approach not only enhances thermal conductivity—critical for efficient energy storage and release—but also introduces electrical conductivity, enabling dual functionalities such as electrothermal conversion and rapid charging and discharging. Although CPs have been extensively utilized for this purpose, there is a noticeable gap in existing reviews that specifically focus on CP-enhanced PCMs. To address this gap, this comprehensive review examines experimental research aimed at improving the electrothermal characteristics of PCMs, with an emphasis on boosting conductivity and storage efficiency through CP incorporation. The review begins by providing an overview of the fundamental principles of electrical and thermal conduction in materials. It then explores commonly used CPs—such as polypyrrole, polyaniline, and poly(3,4-ethylenedioxythiophene) (PEDOT)—and their integration strategies with PCMs. The discussion highlights the unique properties of these polymers and their contributions to enhancing the thermal and electrical conductivity of PCMs. Additionally, it investigates the formation of conductive pathways and their role in amplifying the energy efficiency of nano-enhanced PCMs, comparing the effects of various nano-additives. The study further explores potential applications of CP-enhanced PCMs across diverse fields, including electronics, wearables, energy systems, and advanced thermally regulative materials. To provide a well-rounded perspective, the review outlines recent advancements, identifies current challenges and limitations, and highlights future research opportunities. By fostering a deeper understanding of the interplay between PCMs and CPs, this review contributes to the ongoing efforts to optimize thermal properties and multifunctionality, paving the way for innovative applications and improved energy solutions.