Tailorable polypyrrole nanofilms with exceptional electrochemical performance for all-solid-state flexible supercapacitors

• Published in: Electrochimica acta Vol. 249; pp. 360 - 368
• Main Authors: Bai, Nana, Xu, Zhen, Tian, Yan, Gai, Ligang, Jiang, Haihui, Marcus, Kyle, Liang, Kun
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 20.09.2017; Elsevier BV
• Subjects: Chemical bonds; Chemical oxidation polymerization; Electrochemical analysis; Electrodes; Energy storage; Flexible supercapacitor devices; Hydrogen; Hydrogen bonding; Hydrogen storage; Ice/alcohol interface; Molecular dynamics; Oxidation; Polymerization; Polypyrrole nanofilms; Rolled supercapacitor devices; Scale (corrosion); Solid state; Studies; Supercapacitors; Thickness; Chemical oxidation polymerization; Flexible supercapacitor devices; Ice/alcohol interface; Polypyrrole nanofilms; Rolled supercapacitor devices
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.08.034

Free-standing PPy films with decimeter scale, prepared at an ice/alcohol interface through a simple chemical oxidation polymerization method, can be directly tailored into centimeter-sized film electrode for assembly of rolled supercapacitor devices with high volumetric capacitance and specific energy. [Display omitted] •Self-standing PPy nanofilms are fabricated at the ice/alcohol interface.•PPy nanofilms can be directly tailored for assembling flexible supercapacitor cells.•Film thickness plays a crucial role in electrochemical properties of the cells.•Typical rolled supercapacitor cells (RSC) show a specific energy of 2.3mWhcm−3.•Ecell,v of typical RSCs retains 1.36mWhcm−3 after 10,000 cycles at 2mAcm−2. Flexible supercapacitors exhibiting high specific energy (˃1mWhcm−3) and high specific power are of major research interest in energy storage/conversion systems. In this paper, a strategy has been developed for controlled synthesis of polypyrrole (PPy) nanofilms at the ice/alcohol interface through a simple chemical oxidation polymerization method, yielding free-standing PPy nanofilms with decimeter scale. Evidence from molecular dynamics simulations shows monolayer deposition of pyrrole molecules on the ice surface through hydrogen bonding that supports the formation of PPy films at the ice/alcohol interface. Free-standing PPy films can be directly tailored into film electrodes for all-solid-state flexible planar supercapacitor cells (PSCs) and rolled supercapacitor cells (RSCs). Thickness-dependent electrochemical performance for PSCs and RSCs has been constructed in association with PPy nanofilms. The PSCs and RSCs are made from complete PPy films with thickness of 140±5nm that exhibit specific energy of 0.72 and 2.3mWhcm−3 with corresponding specific power of 51.7 and 111.1mWcm−3, respectively. After 10,000 cycles at a current density of 2mAcm−2, typical RSCs retain a volumetric capacitance of 9.8Fcm−3 and a specific energy of 1.36mWhcm−3, holding great potential in practical applications.