Nanomanufacturing of graphene nanosheets through nano-hole opening and closing

Facile and scalable fabrication of highly dense and high-quality graphene films and articles is extremely attractive for a range of electronic and mechanical applications. Pristine, high-quality graphene with its inherent impermeability poses challenges in fabricating dense films and thick parts with high electrical conductivity due to the difficulty in removing trapped air and/or solvents used in various fabrication methods. To overcome this deficiency, nano-holes were intentionally created in pristine graphene (holey graphene) with an average diameter of approximately 15 nm. The holes serve as pathways for the rapid removal of gases or liquids and enable the fabrication of dense holey graphene nanostructures. Subsequently, a high-temperature process is applied to effectively repair the nano-holes and recover the high-quality graphene conjugated network. Through the creation and repair of the nano-holes, dense graphene articles that exhibited an ultrahigh conductivity of 2209 S/cm and superior thermal conductivity of 863 W/mK were created. This unique processing methodology enables the facile and scalable fabrication of high-quality graphene constructs, which can be easily integrated into the next generation of electronic circuits and high-power battery systems for highly efficient and lightweight thermal management.