title: Polymer-Coated Graphene Aerogel Beads and Supercapacitor Application.
abstract: Graphene aerogels are highly porous materials with many energy and environmental applications; tailoring the structure and composition of pore walls within the aerogel is the key to those applications. Here, by freeze casting the graphene oxide sheets, we directly fabricated freestanding porous graphene beads containing radially oriented through channels from the sphere center to its surface. Furthermore, we introduced pseudopolymer to make reinforced, functional composite beads with a unique pore morphology. We showed that polymer layers can be coated smoothly on both sides of the pore walls, as well as on the junctions between adjacent pores, resulting in uniform polymer-graphene-polymer sandwiched structures (skeletons) throughout the bead. These composite beads significantly improved the electrochemical properties, with specific capacitances up to 669 F/g and good cyclic stability. Our results indicate that controlled fabrication of homogeneous hierarchical structures is a potential route toward high performance composite electrodes for various energy applications.
authors.affiliation: Department of Mechanical Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: An
authors.initials: A
authors.lastname: Ouyang
authors.affiliation: Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, P. R. China.
authors.forename: Anyuan
authors.initials: A
authors.lastname: Cao
authors.affiliation: College of Electromechanical Engineering, Qingdao University , Qingdao, Shandong 266071, P. R. China.
authors.forename: Song
authors.initials: S
authors.lastname: Hu
authors.affiliation: College of Electromechanical Engineering, Qingdao University , Qingdao, Shandong 266071, P. R. China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: Ruiqiao
authors.initials: R
authors.lastname: Xu
authors.affiliation: School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: Jinquan
authors.initials: J
authors.lastname: Wei
authors.affiliation: School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Department of Mechanical Engineering, Tsinghua University , Beijing 100084, P. R. China.
authors.forename: Dehai
authors.initials: D
authors.lastname: Wu
keywords: composite beads; freeze casting; graphene beads; sandwich structure; supercapacitor