title: Supercapacitors Based on Three-Dimensional Hierarchical Graphene Aerogels with Periodic Macropores.
abstract: Graphene is an atomically thin, two-dimensional (2D) carbon material that offers a unique combination of low density, exceptional mechanical properties, thermal stability, large surface area, and excellent electrical conductivity. Recent progress has resulted in macro-assemblies of graphene, such as bulk graphene aerogels for a variety of applications. However, these three-dimensional (3D) graphenes exhibit physicochemical property attenuation compared to their 2D building blocks because of one-fold composition and tortuous, stochastic porous networks. These limitations can be offset by developing a graphene composite material with an engineered porous architecture. Here, we report the fabrication of 3D periodic graphene composite aerogel microlattices for supercapacitor applications, via a 3D printing technique known as direct-ink writing. The key factor in developing these novel aerogels is creating an extrudable graphene oxide-based composite ink and modifying the 3D printing method to accommodate aerogel processing. The 3D-printed graphene composite aerogel (3D-GCA) electrodes are lightweight, highly conductive, and exhibit excellent electrochemical properties. In particular, the supercapacitors using these 3D-GCA electrodes with thicknesses on the order of millimeters display exceptional capacitive retention (ca. 90% from 0.5 to 10 A·g(-1)) and power densities (>4 kW·kg(-1)) that equal or exceed those of reported devices made with electrodes 10-100 times thinner. This work provides an example of how 3D-printed materials, such as graphene aerogels, can significantly expand the design space for fabricating high-performance and fully integrable energy storage devices optimized for a broad range of applications.
authors.affiliation: Engineering Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhu
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Liu
authors.affiliation: Physics and Life Science Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Fang
authors.initials: F
authors.lastname: Qian
authors.affiliation: Physics and Life Science Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: T Yong-Jin
authors.initials: TY
authors.lastname: Han
authors.affiliation: Engineering Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Duoss
authors.affiliation: Physics and Life Science Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Kuntz
authors.affiliation: Engineering Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Spadaccini
authors.affiliation: Physics and Life Science Directorate, Lawrence Livermore National Laboratory , Livermore, California 94550, United States.
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Worsley
authors.affiliation: Department of Chemistry and Biochemistry, University of California , Santa Cruz, California 95064, United States.
authors.forename: Yat
authors.initials: Y
authors.lastname: Li
keywords: 3D printing; Graphene aerogel; periodic macropores; supercapacitors