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

Three-dimensional(3D)functional graphenebased 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 microextrusion printing.In this work,ultra-low-concentration graphene oxide(GO)inks of~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 1×10^(4) to 1×10^(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 51.7×10^(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-superc apacitor 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.