Developing Composite Phase Change Material with Al–Si Base Microencapsulated Phase Change Material and Glass Frit for High Temperature Applications

Abstract

To achieve high energy efficiency and CO 2 reduction during iron-and steelmaking, thermal management is vital. Use of phase change material (PCMs) to store excess energy in the form of latent heat has the potential to realize excellent thermal management. Microencapsulated PCMs (MEPCMs) consisting of an alloy PCM core and an oxide coating have improved corrosion resistance and are easy to mix with other materials. Conventionally, composite PCM pellets are fabricated by mixing glass frit (to aid sintering) with Al-25 mass% Si MEPCM. However, this process has not yet been optimized. In this study, the optimal stoichiometry of composite PCMs prepared using Al-25 mass% Si MEPCM and glass frit was investigated. The pellets were prepared by mixing with glass frit at 60, 80 and 90 mass% of MEPCM, followed by molding and heat treatment. As a result, pellets were successfully fabricated with condition including 60 and 80 mass% of MEPCM. The latent heat capacity of the composite PCM was 146 J g -1 , which was at least 1.59 times higher than that of existing sensible heat storage (SHS) materials. Moreover, the composite PCMs withstood 300 melting and solidification cycles. In summary, composite PCMs with excellent latent heat capacity and durability were successfully prepared. KEY WORDS: latent heat storage; phase change material; thermal energy storage; composite material; microcapsule.

Shell-Driven Localized Oxide Nanoparticles Determine the Thermal Stability of Microencapsulated Phase Change Material

“…Cross-sectional observations (Figure S10b) revealed that the MEPCMs maintained their morphology after the 1000 cycles, albeit with a slight reduction in ΔH m and ΔH s values to 25 and 24 J•g −1 , respectively. In comparison, previous research on the Al-25 wt %Si@α-Al 2 O 3 MEPCM composite established a benchmark for thermal durability over 300 cycles 16,18,23 �a threshold that this study surpassed. Notably, in composite form, Al-25 wt %Si exhibits a considerably higher latent heat energy than Sn, registering at 120−160 J•g −1 .…”

“…This approach not only caters to the pellet form but also allows for modifications into various shapes, such as honeycombs and balls. Utilizing this glass frit, composites of MEPCMs have previously been demonstrated fit for high-temperature applications (555–575 °C) using Al–Si alloy-based MEPCMs. , For Sn, a specific glass frit (ASF-1100, AGC Electronics Co., Ltd.) designed for relatively low firing conditions (460 °C and 30 min) was chosen. This frit, comprising Bi 2 O 3 and B 2 O 3 , served as an effective binder for the MEPCMs (inset Figure e) (detailed methodology for Sn@α-Al 2 O 3 MEPCMs composite making in the Supporting Information).…”