Molecular Regulation of Flexible Composite Solid–Solid Phase Change Materials with Controllable Isotropic Thermal Conductivity for Thermal Energy Storage

Abstract

In recent years, graphene has been introduced into phase change materials (PCMs) to improve thermal conductivity to enhance the heat transfer efficiency in thermal energy storage. However, graphenes tend to aggregate in PCMs, leading to the low thermal conductivity efficient enhancement (TCEE), anisotropic thermal conductivity, and deterioration of mechanical performance of PCMs. In this work, we fabricated biomimetic thermally conductive solid− solid PCMs (SSPCMs) by facile blending of the graphene into well-designed polyurethane SSPCMs, in which the graphene established a controllable and highly efficient isotropic thermally conductive pathway based on the π−π stacking between the graphene and the polymer aromatic ring segment. The asfabricated SSPCMs showed high TCEE (156.78%), excellent flexibility (328% elongation at break), high enthalpy value (>101 J/g), and solid−solid phase transition properties, under 2% loading of graphene. The proportion of in-plane to through-plane thermal conductivity can be adjusted by an elaborate design of the aromatic ring segment in polyurethane SSPCMs. We further demonstrated mechanical flexibility and photothermal property of the composites to reveal their potential in practical applications.

Cerium Methacrylate Assisted Preparation of Highly Thermally Conductive and Anticorrosive Multifunctional Coatings for Heat Conduction Metals Protection

“…For the hybrid F-CB network, h-CMAs could act as bridges between adjacent BN sheets by the virtue of "cation-π" interaction. This could reduce the ITR and provide efficient channels for phonon transport between the adjacent BN sheets compared to pure epoxy, resulting in a significant improvement in TC of F-CB/CEP coating compared with other coatings at the same BN loading [ 30 , 31 ]. Specifically, in comparison with the low TC of 0.76, 0.82, and 0.84 W m −1 K −1 for BN/DEP, BN/CEP, F-CB/CEP coatings, respectively, when the BN content is 20 wt%, the TC of the above coatings reach 2.51, 3.95, and 4.29 W m −1 K −1 after introducing 50 wt% BN.…”

Design of Sustainable Self‐Healing Phase Change Materials by Dynamic Semi‐Interpenetrating Network Structure

“…This phenomenon is rare in the realm of crosslinking polymer-based SSPCMs, as these materials commonly exhibit low enthalpy efficiencies due to the inhibitive impact of the amorphous crosslinking networks on the crystallization of phase change components. [34][35][36][37][38] In this report, the high enthalpy efficiencies of SHPCMs benefit from the advantage of the semi-IPN structure where the fatty alcohols keep free in the range of dynamic disulfide crosslinking polyurethane networks. Simultaneously, the ΔH m and ΔH f for SHPCM-HA-70% reach 144.3 and 143.9 J g −1 , respectively, representing a notable increase compared to numerous existing literature reports (Table S3, Supporting Information).…”

Synthesis and Properties of Dynamic Crosslinking Polyurethane/PEG Shape-Stable Phase Change Materials Based on the Diels–Alder Reaction

“…Making full use of solar energy and recycling waste heat to reduce the global energy consumption, the thermal management technology has significance for our life. Especially, with the rapid development of 5G communication and battery fast-charging technology, the power density of electronic devices has increased dramatically, and the higher heat flux density and thermal failure have become the primary problem restricting their performance and lifetime. , Phase change materials (PCMs) have an advantage in storing and releasing a great amount of latent heat through the phase transition process in a reversible way, so applying PCMs to the thermal management system can effectively reduce the temperature fluctuations and improve the products’ work life. , Therefore, it is an ideal choice for storing thermal energy and improving energy efficiency.…”

“…1,2 Phase change materials (PCMs) have an advantage in storing and releasing a great amount of latent heat through the phase transition process in a reversible way, so applying PCMs to the thermal management system can effectively reduce the temperature fluctuations and improve the products' work life. 3,4 Therefore, it is an ideal choice for storing thermal energy and improving energy efficiency.…”