Compressible, Dense, Three-Dimensional Holey Graphene Monolithic Architecture.

By creating holes in 2D nanosheets, tortuosity and porosity can be greatly tunable, which enables a fast manufacturing process (i.e., fast removal of gas and solvent) toward various nanostructures. We demonstrated outstanding compressibility of holey graphene nanosheets, which is impossible for pristine graphene. Holey graphene powder can be easily compressed into dense and strong monoliths with different shapes at room temperature without using any solvents or binders. The remarkable compressibility of holey graphene, which is in sharp contrast with pristine graphene, not only enables the fabrication of robust, dense graphene products that exhibit high density (1.4 g/cm3), excellent specific mechanical strength [18 MPa/(g/cm3)], and good electrical (130 S/cm) and thermal (20 W/mK) conductivities, but also provides a binder-free dry process that overcomes the disadvantages of wet processes required for fabrication of three-dimensional graphene products. Fundamentally different from graphite, the holey graphene products are both dense and porous, which can enable possible broader applications such as energy storage and gas separation membranes.