3D printing of architectured graphene‐based aerogels by cross‐linking GO inks with adjustable viscoelasticity for energy storage devices
Sancan Han, Jia-Le Quan, Fu-Guo Zhou, Yuhua Xue, Na Li, Fengyu Li, Ding Wang
Abstract
Abstract Three‐dimensional (3D) functional graphene‐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 ~ 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‐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.