title: Self-assembled three-dimensional and compressible interdigitated thin-film supercapacitors and batteries.
abstract: Traditional thin-film energy-storage devices consist of stacked layers of active films on two-dimensional substrates and do not exploit the third dimension. Fully three-dimensional thin-film devices would allow energy storage in bulk materials with arbitrary form factors and with mechanical properties unique to bulk materials such as compressibility. Here we show three-dimensional energy-storage devices based on layer-by-layer self-assembly of interdigitated thin films on the surface of an open-cell aerogel substrate. We demonstrate a reversibly compressible three-dimensional supercapacitor with carbon nanotube electrodes and a three-dimensional hybrid battery with a copper hexacyanoferrate ion intercalating cathode and a carbon nanotube anode. The three-dimensional supercapacitor shows stable operation over 400 cycles with a capacitance of 25 F g(-1) and is fully functional even at compressions up to 75%. Our results demonstrate that layer-by-layer self-assembly inside aerogels is a rapid, precise and scalable route for building high-surface-area 3D thin-film devices.
authors.affiliation: Department of Fibre and Polymer Technology, and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, School of Chemical Science and Engineering Teknikringen 56, 10044 Stockholm, Sweden.
authors.forename: Gustav
authors.initials: G
authors.lastname: Nyström
authors.affiliation: Department of Fibre and Polymer Technology, and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, School of Chemical Science and Engineering Teknikringen 56, 10044 Stockholm, Sweden.
authors.forename: Andrew
authors.initials: A
authors.lastname: Marais
authors.affiliation: Department of Fibre and Polymer Technology, and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, School of Chemical Science and Engineering Teknikringen 56, 10044 Stockholm, Sweden.
authors.forename: Erdem
authors.initials: E
authors.lastname: Karabulut
authors.affiliation: Department of Fibre and Polymer Technology, and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, School of Chemical Science and Engineering Teknikringen 56, 10044 Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Wågberg
authors.affiliation: Department of Materials Science and Engineering, Stanford University, 476 Lomita Mall, McCullough 343, Stanford, California 94305, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Fibre and Polymer Technology, and Wallenberg Wood Science Centre, KTH Royal Institute of Technology, School of Chemical Science and Engineering Teknikringen 56, 10044 Stockholm, Sweden.
authors.forename: Mahiar M
authors.initials: MM
authors.lastname: Hamedi