Extremely anisotropic thermally conductive MXene/CNT hybrid film for battery thermal management

Abstract

The higher power density of energy storge systems necessitates advanced thermal management strategies and materials, especially for the anisotropic thermally conductive films (TCFs). However, it remains great challenging for assembling high-performance anisotropic TCFs. Here, we demonstrate an extremely anisotropic TCFs with carbon nanotubes (CNT) and MXene nanosheets through alternating layer-by-layer blade coating technique with interfacial covalent bridging. The resultant films exhibit a high in-plane thermal conductivity of 71.9 ± 1.3 W m-1 K-1 and an extremely low inter-plane thermal conductivity of 0.06 ± 0.01 W m-1 K-1, yielding a record-high anisotropy factor of 1220 ± 24. This is enabled by the substantial interfaces between MXene nanosheets and CNT that impede the inter-plane thermal transport while the highly aligned layered structure maintains high intra-plane thermal conductivity. And the resultant films show strong mechanical properties and efficient thermal management performance for battery. Our work offers a new pathway for assembling high-performance TCFs used in the battery thermal management.