Ultralight, Highly Compressible Graphene Cellular Materials with Enhanced Mechanical and Electrical Performance

摘要

Conventional three-dimensional graphene cellular materials (GCMs) from chemically derived graphene oxide undergo low mechanical strength, severe plastic deformation and poor electrical conductivity. Herein, ultralight, ultraelastic, excellent mechanical and electrically conductive GCMs have been successfully prepared by the self-assembly of graphene nanosheets by extensive hydrogen bonds generated from a glycolic acid crosslinker. Meanwhile, ethanol-water solution is used to dramatically restrict the volume expansion of water converting into ice crystal during the freeze process. Eventually, the GCMs exhibit ultralow densities of about 4.3 mg cm(-3), and can be fabricated on a large scale (volume of similar to 350 cm(3)). The GCMs have a maximum reversible strain of ca. 90% in the whole density range from 4.3 mg cm(-3) to 25.3 mg cm(-3). Young's moduli (E) are from 13.7 kPa (rho=4.3 mg cm(-3)) to 125.1 kPa (rho=25.3 mg cm(-3)), with the scale of E similar to rho(2.1), and the exponent n is less than the GCMs previously reported. The GCMs also have high electrical conductivities of about 98.1 S/m (rho=25.3 mg cm(-3)). Our work provides a facile method for the fabrication of ultralight, highly compressible and conductive GCMs, paving the way towards future potential applications in energy storage and conversions, adsorbents for the environment, etc.