3D printing of architectured graphene-based aerogels by cross-linking GO inks with adjustable viscoelasticity for energy storage devices

Three-dimensional (3D) functional graphene-complex-shaped, graphene-based architectures for scalable based architecture with superior electrical conductivity and good mechanical strength has promising applications in energy storage and electrics. Viscoelasticity-adjustable inks make it possible to achieve desired 3D architectures with interconnected and continuous interior networks by micro-extrusion printing. In this work, ultra-low-concentration graphene oxide (GO) inks of similar to 15 mg.ml(-1) have been obtained and demonstrated in direct 3D printing with a facile cross-linking (direct ink writing). The rheological behavior of the GO strategy by cations, which is the lowest concentration to achieve direct ink writing inks, could be adjusted from 1 x10(4) to 1 x 10(5) Pa.s(-1) with different concentrations of cations due to strong cross-linking networks between GO sheets and cations. Meanwhile, the specific strength and electrical conductivity of 3D-printed graphene architecture are notably enhanced, reaching up to 51.7 x 10(3) N.m.kg(-1) and 119 S.m(-1), which are superior to conventional graphene aerogels. Furthermore, 3D printing graphene-based architecture assembled in micro-supercapacitor exhibits excellent electrochemical performance, which can be ascribed to the effective ion transportation through the interconnected networks. The strategy demonstrated is useful in the design of complex-shaped, graphene-based architectures for scalable manufacturing of practical energy storage applications.

Automated summary

Functional graphene-based architectures with superior electrical conductivity and good mechanical strength were achieved through micro-extrusion printing using viscoelasticity-adjustable inks. The rheological behavior and specific strength of the printed graphene architectures were notably improved by strong cross-linking networks and reached values higher than conventional graphene aerogels. The 3D-printed graphene-based architectures also showed excellent electrochemical performance as micro-supercapacitors due to effective ion transportation.