Collaborative electrospinning and ice-templating for sea urchin-inspired aerogel microsphere: Unraveling functional mechanisms in thermally conductive phase change composites

With the increased integration of electronic devices, effective heat management becomes imperative. Thermally conductive phase change composites play a vital role by efficiently conducting heat and utilizing matrix phase change for heat storage. Conventional materials encounter difficulties such as low thermal conductivity, restricted heat storage density, and vulnerability to leakage. This study presents a novel method combining electrospinning and ice-templating method to produce aerogel microspheres with sea urchin-like structures, resolving mentioned issues. The microspheres exhibit a radial microstructure and controllable size, serving as efficient fillers for the easy production of high-performance phase change materials. The microspheres are able to create an efficient interlocking mechanism with surface spike structures, forming a continuous thermal conduction and spatially confined network in the composite material. At a filler content of 43.9 vol%, the thermal conductivity of the Al aerogel microsphere/paraffin composite reaches a peak value of 3.2 W/mK, accompanied by a contact thermal resistance of 1.2 × 10⁻⁶ Km²/W. Subjecting the composite to elevated temperatures well above the matrix's phase change temperature preserves its structural stability. This work reports a new structured filler moulding method that supports the development of high performance thermally conductive phase change composites.