title: Monolithic Flexible Supercapacitors Integrated into Single Sheets of Paper and Membrane via Vapor Printing.
abstract: A novel approach to fabricate supercapacitors (SCs) via vapor printing, specifically oxidative chemical vapor deposition (oCVD), is demonstrated. Compared to stacking multiple layers into a SC, this method enables the monolithic integration of all components into a single-sheet substrate, minimizing the inactive materials and eliminating the possibility of multilayer delamination. Electrodes comprised of pseudocapacitive material, poly(3,4-ethylenedioxythiophene) (PEDOT), are deposited into both sides of a sheet of flexible porous substrate. The film deposition and patterning are achieved in a single step. The oCVD PEDOT penetrates partially into the porous substrate from both surfaces, while leaving the interior of the substrate serving as a separator. Near the surface, the PEDOT coating conforms to the substrate's structure without blocking the pores, resembling the substrate's intrinsic morphology with high surface area. The porously structured PEDOT coating, paired with in situ ion gel electrolyte synthesis, gives enhanced electrode-electrolyte interfaces. The monolithic device demonstrates high volumetric capacitance (11.3 F cm-3), energy density (2.98 mWh cm-3), and power density (0.42 W cm-3). These outstanding performance metrics are attributed to the large loading of active materials, minimization of inactive materials, and good electrode-electrolyte interfaces. SC arrays can be printed on a single substrate without the use of wire interconnects.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Andong
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Kovacik
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Nolan
authors.initials: N
authors.lastname: Peard
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Wenda
authors.initials: W
authors.lastname: Tian
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Hilal
authors.initials: H
authors.lastname: Goktas
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lau
authors.affiliation: Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: Dunn
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
authors.forename: Karen K
authors.initials: KK
authors.lastname: Gleason
keywords: chemical vapor deposition; conducting polymers; electrode-electrolyte interfaces; printed electronics; supercapacitors