A hierarchically encapsulated phase-change film with multi-stage heat management properties and conformable self-interfacing contacts for enhanced interface heat dissipation

Abstract

With the rapid evolution of power and packing densities of microelectronic and energy storage devices, timely heat dissipation towards an instantaneous high intensity heat flow is becoming increasingly significant to maintain system reliability. A highly thermally conductive solid–liquid phase change film can be a potential candidate for the next-generation heat dissipation material by coupling the efficient heat storage and self-softening properties during its isothermal phase transition process. Herein, a porous phase change film composed of high enthalpy paraffin microcapsules (213.7 J g⁻¹), impregnated with an n-docosane and nano–Si₃N₄ mixture, is shown to be an ideal phase change thermal interface material (PhC-TIM). The hierarchically encapsulated structures, with two-stage thermal management properties, guarantee temperature control of electronic devices by storage of instantaneous excessive heat, without degradation of thermal conductivity (3.8 W m⁻¹ K⁻¹) after 500 heating–cooling cycles. Furthermore, the presented PhC-TIM demonstrates ultra-flexibility in the working state, which can form tight interface contact and results in low thermal contact resistance. The hot-spot temperatures of a light-emitting diode (LED) chip and a lithium-ion battery module equipped with the HEPCF were decreased by 15 °C and 20 °C, respectively. The obtained results open opportunities for PhC-TIMs as efficient thermal dissipation materials for electronics cooling and suppressing thermal runaway in energy storage devices.