Graphene-templated carbon aerogels combining with ultra-high electrical conductivity and ultra-low thermal conductivity

Nanostructural-strengthened carbon composite aerogels were prepared by sol-gel polymerization of resorcinol (R) and formaldehyde (F) with basic catalyst in graphene oxide (GO) aqueous dispersion. Graphene nanosheets (GNS) as soft anti-shrinkage additive, well incorporated into carbon aerogels (CAs) matrix, significantly reinforce the nanostructural skeleton of CAs and effectively inhibit collapse of nanopores and linear shrinkage during carbonization. By further optimization of loading GO content, the resultant GNS/CAs exhibited high surface areas (as high as 3214 m2 g−1) and a low appearance density of 23.5 mg cm−3 at the same time, which are the highest surface areas for GNC/CAs ever reported. In addition, the resultant composite CAs exhibited high deformation capacitor (∼20.5%), excellent electrical conductivity (2.25 Ω−1 cm−1 at a density of 23.5 mg cm−3), and extremely low thermal conductivity of 0.027 W m−1 K−1, comparable with that of the pristine CAs. Together with the easy handling and outstanding electrical/thermal properties, the resulting materials could have further applications such as thermal insulator for thermal protection system and electrode materials.