Corannulene Extended Viologen-Based Ambipolar Polymers for Transparent-to-Color Electrochromic Supercapacitors

Abstract

This paper describes ambipolar polymers made of penta­(N-alkyl carbazole)-corannulene extended viologen for use as an electrochromic supercapacitor. Electrochromic supercapacitors with visible energy storage levels and high charge/discharge rates have been used to power wearable and portable intelligent electronics. Redox-active π-conjugated polymers have received significant attention because they can change color and store energy through a faradaic reaction during the doping/dedoping process. However, conjugated ambipolar polymers used as electrochromic supercapacitors generally display color at both neutral and doped states because of the extensive conjugation of the donor and acceptor units. The alkyl chain as a nonconjugated linker bridged the donor and acceptor units to help retain the electrochromic behaviors of the individual unit and pursue a transparent-to-color electrochromic supercapacitor. Still, the length of the alkyl chain affects the optical contrast and specific capacitance of the polymers. An ambipolar polymer with a butyl chain as linker displays the highest optical contrast and the best performance of specific capacitance at 291 and 394 F g–1 in the p-doping and n-doping regions, respectively. Finally, the ambipolar polymer was applied to fabricate a gel-type electrochromic device, which demonstrates a transparent-to-green switching during the charge/discharge process.

Variable-Tint Electrochromic Supercapacitor with a Benzyl Hexenyl Viologen-Prussian Blue Architecture and Ultralong Cycling Life

“…In a previous report, the areal SC of a viologen (wherein both ends of 4,4′-bipyridyl were connected to triarylamine moieties)-based supercapacitor was reported to be 1.25 mF cm –2 at 0.01 mA cm 2 . In another study, a penta( N -alkyl carbazole)-corannulene extended viologen delivered a SC of 30 F g –1 at 0.02 mA cm –2 A S C = false( i normala × t false) / V S C = false( i normalg × t false) / V E = false( normalS normalC × V 2 false) / 2 P = E / t …”

“…Further, the Br – /Br 3 – redox couple is also highly corrosive, thus limiting the practical applications of this viologen. Another study used a penta­( N -alkyl carbazole)-corannulene extended viologen in an ESC; however, the discharge times were very short (∼30–35 s), and the highest transmission modulation was ∼56% at 660 nm, with a patchy green colored state . Another report focused on an ethyl viologen and dimethyl ferrocene based ESC, which showed a coloration efficiency of 116.1 cm 2 C –1 and a calculated ASC of 2.5 mF cm –2 .…”

“…Another study used a penta(N-alkyl carbazole)-corannulene extended viologen in an ESC; however, the discharge times were very short (∼30−35 s), and the highest transmission modulation was ∼56% at 660 nm, with a patchy green colored state. 14 Another report focused on an ethyl viologen and dimethyl ferrocene based ESC, which showed a coloration efficiency of 116.1 cm 2 C −1 and a calculated ASC of 2.5 mF cm −2 . 15 In the present work, the following are the novel features of our device.…”

Macromolecular Architectures of Corannulene: Synthesis, Properties, and Applications of Polymers Containing a Molecular Bowl of Carbon

“…Recently, Lin and Luo have begun an impressive research initiative in which 5-fold substitution on corannulene is first executed through Scott’s direct borylation and a Suzuki coupling approach to obtain monomers with a donor/acceptor-type of structural arrangement (Figure b). , These monomers are then polymerized through an electropolymerization process. It is anticipated that the terminal aromatic rings of the arms placed on the corannulene core are connected through new covalent bonds during such a polymerization to yield cross-linked networks 62 – 65 .…”

Flexible Molecular Electrochromic Devices Run by Low‐Cost Commercial Cells

“…[18,19] Viologens, among the electrochromic organic materials have considered the utmost attention due to their ease of chemical structures control and modification, tunable optoelectronic properties, wider ranges of thermal stability, bistable redox states, room temperature solubility, air-stability, large-area surface coating and easy characterization, can withstand larger electrochemical potential window, coloration both in solution and solid-state, and long-range charge transport ability. [13,20,21] Depending on the substituents, viologens may exist in three distinct redox forms: dication (pale yellow/red-colored or colorless), mono-radical-cation (violet-blue/green), and diradical (generally colorless). [13] In an application to a bias, the dicationic form (V 2+ ) undergoes two different forms, a cation radical (V +• ) and a neutral species (V 0 ), and their radical cations exhibit exceptional stability.…”