Boosting flexible thermal management and absorption-dominant electromagnetic shielding through surface engineering of electrochemically-exfoliated graphene

The miniaturization, intense integration, and high-density power of modern electronic and energy devices necessitate extensive management of thermal energy and electromagnetic waves. Creating lightweight, stable, and multifunctional materials to meet these demands remains a challenge. Here, we describe preparing graphene aerogel through the condensation dehydration of hydrophilic polymers and further forming scenario-adaptive multifunctional films through 2500 °C heat treatment and paraffin hybridization. The graphene materials exhibit extensive thermal management with high performances covering high thermal conductivity (up to 76.4 W·m −1 ·K −1 ), superior heat dissipation, tunable electro-thermal conversion, cycling heat storage, and flame retardancy. Additionally, they provide tunable and effective electromagnetic interference shielding performances with high specific shielding effectiveness (up to an average of 91.6 dB, maximum of 123 dB) in a wide frequency range, featuring anti-corrosive absorption-dominant shielding across the X-band, Ku-band, and K-band. Surface engineering of graphene including tuning surface chemical groups and interface couplings contributes to flexible thermal management and electromagnetic shielding. This work might offer a green strategic approach to developing extensive thermal and electromagnetic wave managements of graphene materials.