Phase Change Thermal Storage Materials for Interdisciplinary Applications.

Functional phase change materials (PCMs) capable of reversibly storing and releasing tremendous thermal energy during the isothermal phase change process have recently received tremendous attention in interdisciplinary applications. The smart integration of PCMs with functional supporting materials enables multiple cutting-edge interdisciplinary applications, including optical, electrical, magnetic, acoustic, medical, mechanical, and catalytic disciplines etc. Herein, we systematically discuss thermal storage mechanism, thermal transfer mechanism, and energy conversion mechanism, and summarize the state-of-the-art advances in interdisciplinary applications of PCMs. In particular, the applications of PCMs in acoustic, mechanical, and catalytic disciplines are still in their infancy. Simultaneously, in-depth insights into the correlations between microscopic structures and thermophysical properties of composite PCMs are revealed. Finally, current challenges and future prospects are also highlighted according to the up-to-date interdisciplinary applications of PCMs. This review aims to arouse broad research interest in the interdisciplinary community and provide constructive references for exploring next generation advanced multifunctional PCMs for interdisciplinary applications, thereby facilitating their major breakthroughs in both fundamental researches and commercial applications.

Engineering 2D MXene and LDH into 3D Hollow Framework for Boosting Photothermal Energy Storage and Microwave Absorption.

2D MXene is highly preferred for photothermal energy conversion and microwave absorption. However, the aggregation issue, insufficient dielectric loss capacity, and lack of magnetic loss capacity for MXene severely hinder its practical applications. Herein, the authors propose multi-dimensional nanostructure engineering to electrostatically assemble 2D MXene and layered double hydroxides (LDH) derived from ZIF-67 polyhedron into a 3D hollow framework (LDH@MXene), and subsequently calcined to construct a Co nanoparticle-modified 3D hollow C-LDH@MXene framework to encapsulate a paraffin wax (PW) phase change material (PCM). The 3D hollow C-LDH@MXene framework not only prevents 2D MXene from aggregation but also contributes a high thermal energy storage density (131.04 J g-1 ). Benefiting from a 3D conductive network facilitating the rapid transport of photons and phonons from the interface to the interior and the synergistic localized surface plasmon resonance (LSPR) effect of MXene and Co magnetic nanoparticles, the C-LDH@MXene-PW composite PCM yielded a high photothermal storage efficiency of 96.52%. Besides, C-LDH@MXene-PW composite PCMs also exhibited efficient microwave absorption with a minimum reflection loss of -20.87 dB at 13.30 GHz with a matching thickness of only 2 mm. This distinctive design provides constructive references for the development of integrated composite materials for energy storage and microwave absorption.

Aerogels Meet Phase Change Materials: Fundamentals, Advances, and Beyond.

Benefiting from the inherent properties of ultralight weight, ultrahigh porosity, ultrahigh specific surface area, adjustable thermal/electrical conductivities, and mechanical flexibility, aerogels are considered ideal supporting alternatives to efficiently encapsulate phase change materials (PCMs) and rationalize phase transformation behaviors. The marriage of versatile aerogels and PCMs is a milestone in pioneering advanced multifunctional composite PCMs. Emerging aerogel-based composite PCMs with high energy storage density are accepted as a cutting-edge thermal energy storage (TES) concept, enabling advanced functionality of PCMs. Considering the lack of a timely and comprehensive review on aerogel-based composite PCMs, herein, we systematically retrospect the state-of-the-art advances of versatile aerogels for high-performance and multifunctional composite PCMs, with particular emphasis on advanced multiple functions, such as acoustic-thermal and solar-thermal-electricity energy conversion strategies, mechanical flexibility, flame retardancy, shape memory, intelligent grippers, and thermal infrared stealth. Emphasis is also given to the versatile roles of different aerogels in composite PCMs and the relationships between their architectures and thermophysical properties. This review also showcases the discovery of an interdisciplinary research field combining aerogels and 3D printing technology, which will contribute to pioneering cutting-edge PCMs. This review aims to arouse wider research interests among interdisciplinary fields and provide insightful guidance for the rational design of advanced multifunctional aerogel-based composite PCMs, thus facilitating the significant breakthroughs in both fundamental research and commercial applications.

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.

Carbon-Based Composite Phase Change Materials for Thermal Energy Storage, Transfer, and Conversion.

Phase change materials (PCMs) can alleviate concerns over energy to some extent by reversibly storing a tremendous amount of renewable and sustainable thermal energy. However, the low thermal conductivity, low electrical conductivity, and weak photoabsorption of pure PCMs hinder their wider applicability and development. To overcome these deficiencies and improve the utilization efficiency of thermal energy, versatile carbon materials have been increasingly considered as supporting materials to construct shape-stabilized composite PCMs. Despite some carbon-based composite PCMs reviews regarding thermal conductivity enhancement, a comprehensive review of carbon-based composite PCMs does not exist. Herein, a systematic overview of recent carbon-based composite PCMs for thermal storage, transfer, conversion (solar-to-thermal, electro-to-thermal and magnetic-to-thermal), and advanced multifunctional applications, including novel metal organic framework (MOF)-derived carbon materials are provided. The current challenges and future opportunities are also highlighted. The authors hope this review can provide in-depth insights and serve as a useful guide for the targeted design of high-performance carbon-based composite PCMs.

Phase Change Materials for Electro-Thermal Conversion and Storage: From Fundamental Understanding to Engineering Design.

Advanced functional electro-thermal conversion phase change materials (PCMs) can efficiently manage the energy conversion from electrical energy to thermal energy, thereby playing a significant role in sustainable energy utilization. Considering the inherent insulating properties of pristine PCMs, electrically conductive supporting materials are widely used to encapsulate PCMs to prepare composite PCMs for electro-thermal conversion and storage. Herein, we comprehensively review the recent advances in different electro-thermal conversion PCMs, mainly including carbon-based PCMs (carbon nanotubes [CNTs], graphene, biomass-derived carbon, graphite, highly graphitized carbon, and metal organic frameworks [MOFs]-derived carbon) and MXene-based PCMs. This review aims to provide an in-depth understanding of the electrothermal conversion mechanism and the relationships between structure design (random and array-oriented structure or single and hybrid supporting materials) and electrothermal properties, thereby contributing profound theoretical and experimental bases for the construction of high-performance electro-thermal conversion PCMs. Finally, we highlight the current challenges and future prospects.

Toward Tailoring Chemistry of Silica-Based Phase Change Materials for Thermal Energy Storage.

Efficient thermal energy harvesting using phase change materials (PCMs) has great potential for thermal energy storage and thermal management applications. Benefiting from these merits of pore structure diversity, convenient controllability, and excellent thermophysical stability, SiO2-based composite PCMs have comparatively shown more promising prospect. In this regard, the microstructure-thermal property correlation of SiO2-based composite PCMs is still unclear despite the significant achievements in structural design. To enrich the fundamental understanding on the correlations between the microstructure and the thermal properties, we systematically summarize the state-of-the-art advances in SiO2-based composite PCMs for tuning thermal energy storage from the perspective of tailoring chemistry strategies. In this review, the tailoring chemistry influences of surface functional groups, pore sizes, dopants, single shell, and hybrid shells on the thermal properties of SiO2-based composite PCMs are systematically summarized and discussed. This review aims to provide in-depth insights into the correlation between structural designs and thermal properties, thus showing better guides on the tailor-made construction of high-performance SiO2-based composite PCMs. Finally, the current challenges and future recommendations for the tailoring chemistry are also highlighted.