Boosting thermal energy transport across the interface between phase change materials and metals via self-assembled monolayers

Zi-Yu Shan; Meng An; Xing Zhang; Hai Zhang; Wei-Gang Ma

doi:10.1088/1361-648X/ad48ef

Boosting thermal energy transport across the interface between phase change materials and metals via self-assembled monolayers

J Phys Condens Matter. 2024 May 20;36(33). doi: 10.1088/1361-648X/ad48ef.

Authors

Zi-Yu Shan^{1

2}, Meng An^{3

4}, Xing Zhang¹, Hai Zhang², Wei-Gang Ma¹

Affiliations

¹ Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China.
² Department of Energy and Power Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
³ College of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, People's Republic of China.
⁴ Department of Mechanical Engineering, Graduate School of Engineering, The University of Tokyo, 7-3-1, Bunkyo-ku, Tokyo 113-8656, Japan.

PMID: 38718812
DOI: 10.1088/1361-648X/ad48ef

Abstract

Thermal energy storage using phase change materials (PCMs) has great potential to reduce the weather dependency of sustainable energy sources. However, the low thermal conductivity of most PCMs is a long-standing bottleneck for large-scale practical applications. In modifications to increase the thermal conductivity of PCMs, the interfacial thermal resistance (ITR) between PCMs and discrete additives or porous networks reduces the effective thermal energy transport. In this work, we investigated the ITR between a metal (gold) and a polyol solid-liquid PCM (erythritol) at various temperatures including temperatures below the melting point (300 and 350 K), near the melting point (390, 400, 410 K, etc) and above the melting point (450 and 500 K) adopting non-equilibrium molecular dynamics. Since the gold-erythritol interfacial thermal conductance (ITC) is low regardless of whether erythritol is melted or not (<40 MW m^-2K^-1), self-assembled monolayers (SAMs) were used to boost the interfacial thermal energy transport. The SAM with carboxyl groups was found to increase the ITC most (by a factor of 7-9). As the temperature increases, the ITC significantly increases (by ∼50 MW m^-2K^-1) below the melting point but decreases little above the melting point. Further analysis revealed that the most obvious influencing factor is the interfacial binding energy. This work could build on existing composite PCM solutions to further improve heat transfer efficiency of energy storage applications in both liquid and solid states.

Keywords: interface; molecular dynamics; phase change material; self-assembled monolayer; thermal energy transport.