Advanced electromagnetic shielding and excellent thermal management of flexible phase change composite films

Abstract

Endowing the integration of electromagnetic interference (EMI) shielding and thermal management is of great practical significance but remains extremely challenging, especially EMI stability in solid-liquid phase transformation process. Here, innovative flexible composite phase change films (PF/AC/PEG-X (X = 2, 4, 6, 8)) was developed inspired by the unique inter-structure of seedpod composed by scattered honeycomb pores and large multicellular interlocking of lotus seeds and lotus houses. The rich porous structure of eucalyptus-derived carbon not only realizes the high load of PEG (67.4%) and enhanced heat conversion efficiency, but also complete the reflection and absorption of electromagnetic waves (59.83 dB), and develop the steady-state EMI properties during solid-liquid transition under photo-thermal interaction. Optimized PF/AC/PEG-2 film has highlighted a mechanical strength of 45.1 MPa, an energy storage density of 121.3 J/g, a photothermal conversion efficiency of 89.42%, high light/thermal cycle stability (95%), and excellent flexibility. This flexible composite phase change films are promising for a wide range of applications in efficient thermal management and electromagnetic shielding of electronic devices.