Exceptional electrical and thermal transport properties in tunable all-graphene papers

Lightweight thermally conductive materials of various electrical features, ranging from insulators such as boron nitride composites to highly conductive graphene-based materials, are increasingly attractive in substituting traditional metal materials for many practical applications. Herein we take a new insight into the electrical and thermal transport properties of the flexible all-graphene papers, where electrically and thermally insulating graphene oxide nanosheets (GO) serve as unique interfaces in the graphene papers stacked by electrically and thermally conductive graphene nanosheets (GN). Anisotropic all-graphene papers with decoupling of thermal and electrical transport properties have been achieved based on controlling the electron and phonon transport paths at the GN–GO interfaces. The fundamental mechanism of the exclusive electrical and thermal transport behaviors in the all-graphene papers has been discussed, indicating more advantageous features in manipulating the transport properties in comparison with other conventional graphene/polymer composites. The implication of the tunable thermal conductivity in the entire semi-conductive range suggests a conceptually novel stage toward fabricating advanced graphene materials of various electrical features for wide thermal management.