Micro-encapsulation of a low-melting-point alloy phase change material and its application in electronic thermal management

The application of liquid metal (LM) with high thermal conductivity in electronic thermal management is an emerging hotspot, but leakage of LM can cause environmental pollution and lead to corrosion of electronic equipment, thereby affecting the safety of its operation. Moreover, large temperature fluctuation will be caused for the limited thermal storage capacity of LM. To solve the above problems, it is urgent to develop LM-based microcapsules with high thermal conductivity and high thermal storage capacity. Herein, a novel micro-encapsulated phase change material (MEPCM) with an internal void, composed of liquid metal Sn–Bi–In core and PMMA shell, was firstly fabricated via liquid phase micro-encapsulation method. The results showed that microcapsules maintained good morphology and efficient thermal storage capacity (246.46 J cm−3) after 300 thermal cycles, 97.12% of that before the cycle (253.77 J cm−3). Subsequently, the MEPCM-based composite was prepared by mixing MEPCM into thermal gel. The enthalpy of 50 wt% MEPCM composite was 126.72 J cm−3, and the thermal conductivity of it was 3.23 W m−1·K−1, while that of thermal gel was 0.98 W m−1·K−1. Then the 50 wt% MEPCM-based composite was applied for LED chip, and the temperature of chip was 71.1 °C, 11.2 °C lower than that of thermal gel. Therefore, MEPCM-based composites with high thermal conductivity and thermal storage capacity are considerably potential for electronic thermal management.