Highly flexible few-layer Ti3C2 MXene/cellulose nanofiber heat-spreader films with enhanced thermal conductivity

Abstract

MXenes, two-dimensional transition metal carbides, exhibit excellent properties in many fields such as energy storage. The first discovered, Ti₃C₂, has been widely used in lithium ion batteries. However, thermal properties and delamination of few-layer MXenes have been insufficiently explored. In this work, few-layer Ti₃C₂ nanosheets were prepared under ultra-high pressure and by low temperature exfoliation. Furthermore, a flexible cellulose nanofiber (CNF)/Ti₃C₂ composite film was fabricated by simple vacuum-assisted filtration. The heat spreader of Ti₃C₂/CNF paper exhibits in-plane and out-of-plane thermal conductivities of 11.57 and 1.57 W m⁻¹ K⁻¹ with 50 wt% loading of filler, respectively. Moreover, the synthesized Ti₃C₂/CNF composite films presented outstanding flexibility because the films can be folded to any shape, which enables Ti₃C₂/CNF composite films to be potentially applied in flexible electronic devices for heat dissipation.