Vapor-Phase Polymerization of Nanofibrillar Poly(3,4-ethylenedioxythiophene) for Supercapacitors

Abstract

Nanostructures of the conducting polymer poly(3,4-ethylenedioxythiophene) with large surface areas enhance the performance of energy storage devices such as electrochemical supercapacitors. However, until now, high aspect ratio nanofibers of this polymer could only be deposited from the vapor-phase, utilizing extrinsic hard templates such as electrospun nanofibers and anodized aluminum oxide. These routes result in low conductivity and require postsynthetic template removal, conditions that stifle the development of conducting polymer electronics. Here we introduce a simple process that overcomes these drawbacks and results in vertically directed high aspect ratio poly(3,4-ethylenedioxythiophene) nanofibers possessing a high conductivity of 130 S/cm. Nanofibers deposit as a freestanding mechanically robust film that is easily processable into a supercapacitor without using organic binders or conductive additives and is characterized by excellent cycling stability, retaining more than 92% of its initial capacitance after 10,000 charge/discharge cycles. Deposition of nanofibers on a hard carbon fiber paper current collector affords a highly efficient and stable electrode for a supercapacitor exhibiting gravimetric capacitance of 175 F/g and 94% capacitance retention after 1000 cycles.

Conducting‐Polymer‐Based Materials for Electrochemical Energy Conversion and Storage

“…D'Arcy et al fabricated freestanding films of PEDOT nanofibers through an evaporative vapor-phase polymerization process (Figure 5e). [64] The nanofiber structure increased the active surface area of the electrode and maximized ion access (Figure 5f). The PEDOT electrode with a high conductivity of 130 S cm −1 showed a specific capacitance of 175 F g −1 (Figure 5g).…”

“…[62] In this case, volume swelling/shrinking during the repeated charging/ discharging process is better accommodated, thereby increasing the cyclic stability of supercapacitors. [63][64][65][66] Yu and co-workers successfully synthesized 3D nanostructured PPy hydrogel through an organic/aqueous biphasic interfacial polymerization method. The PPy hydrogel had a porous nanostructure with interconnected hollow sphere morphology (Figure 5a).…”

“…e-h) Reproduced with permission. [64] Copyright 2014, American Chemical Society; Layered PEDOT:PSS film electrode: i) photograph, j) cross-sectional SEM image, k) Ragone plots, l) cyclic stability at a scan rate of 100 mV s −1 . i-l) Reproduced with permission.…”

Recent Advances in Nanostructured Conducting Polymers: from Synthesis to Practical Applications

“…The role of co-vapor in the vapor-phase polymerization (VPP) method was studied [105] An application for drug storage was carried out by depositing PPy using the chemical vapor deposition (CVD) method [106] PEDOT The dependence of electrical conductivity on VPP temperature was discussed [107] Single-crystal CP nanowires were developed using VPP with liquid-bridge-mediated nanotransfer printing [108] A one-step fabrication of 2D nanoparticles was investigated [109] The advantages of directly depositing CP nanofibers was demonstrated [110] Polymers …”

Electropolymerized Star-Shaped Benzotrithiophenes Yield π-Conjugated Hierarchical Networks with High Areal Capacitance

“…[8][9][10] Electropolymerization approaches using monomer solutions can be performed reproducibly, while incorporating ions and counterions in the process of forming open, porous nanostructured films. 11,12 Thus, several studies have emphasized the range of achievable morphologies using conjugated polymers such as polyaniline (PANI), 13,14 polypyrrole, 14,15 polythiophene, 16 and poly(3,4-ethylenedioxythiophene) (PEDOT) 17,18 , derived from the electropolymerization of commercially available monomers. For example, varying the experimental conditions for the synthesis of PANI induces considerable morphological changes that impact material capacitance (i.e., nanospheres to nanorods to nanofibers).…”