Ultra-high thermal conductivity FGN/PVA/MXene composite films with good electrical insulation

The polyvinyl alcohol (PVA) -based composite films with the high thermal conductivity and excellent electrical insulation have attracted more and more attention due to their advantages such as light weight and easy processing. Herein, a series of three-component fluorographene nanosheets (FGN)/PVA/MXene(FPM) films were prepared by vacuum assisted filtration technology with the single layer FGN (1.5–2.5 μm) and PVA as main raw materials and a small amount of Ti3C2Tx MXene nanosheets (200–600 nm) as the third phase. The FPM films had ultra-high in-plane thermal conductivity of 122.5 W/(m·K) when the addition of Ti3C2Tx MXene was 0.8 wt% of the composite film. The reason is that the Ti3C2Tx MXene nanosheets replace the high thermal resistance PVA molecules and connect the adjacent FGN powders horizontally (via hydrogen bonding), thus greatly reducing phonon scattering at the gap. The FPM films achieve extremely high in-plane thermal conductivity while maintaining excellent insulation and can be used for heat dissipation of small electrical appliances (such as mobile phone CPU). Meanwhile, it provides a new idea for the preparation of composite films with the low cost and high thermal conductivity.