A comprehensive review on composite phase change materials for sustainable thermal energy solutions: Advances and barriers

Abstract

Composite Phase Change Materials (CPCMs) have gained significant attention for their potential in thermal energy storage (TES) due to their high latent heat capacity. These materials offer a promising solution for addressing global energy challenges, especially in renewable energy applications. This review summarizes recent advances in CPCMs, discusses existing challenges, and suggests future research directions. While phase change materials (PCMs) are key for thermal management due to their high energy density, they face limitations such as low thermal conductivity, leakage during phase transitions, and poor stability. To address these issues, additives like nanoparticles, expanded graphite, and polymers have been incorporated into CPCMs, improving thermal conductivity, stability, and energy storage efficiency. Research has shown that carbon-based nanomaterials can enhance thermal conductivity by up to 137% and improve thermal cycling durability. Innovative CPCM formulations, such as eutectic mixtures and hybrid composites, help overcome phase stability and leakage issues. Microencapsulation has also made strides, enhancing PCM containment and functionality, with dual-layer encapsulated CPCMs maintaining latent heat efficiency for over 200 cycles with minimal degradation. Nanomaterials like graphene and carbon nanotubes further reinforce thermal properties. CPCMs are widely used in solar thermal systems, building temperature regulation, and industrial waste heat recovery. In concentrated solar power systems, CPCMs have shown outstanding thermal storage capabilities and efficiencies, with some surpassing 90% solar-to-thermal conversion. Despite these advances, challenges remain, including high production costs, material degradation, and environmental concerns. Future research should focus on improving stabilization, scalability, and eco-friendly materials. The review concludes by highlighting research gaps and the potential of integrating CPCMs with smart technologies for dynamic thermal management, underscoring the need for cross-disciplinary strategies to optimize CPCM performance for broader adoption.