Poly[Bis-EDOT-Isoindigo]: An Electroactive Polymer Applied to Electrochemical Supercapacitors

Abstract

Poly[6,6′-bis(ethylene-3,4-dioxythien-2-yl)]-N,N′-dialkylisoindigo (PBEDOT-iI) was synthesized and incorporated as an electroactive material into electrochemical supercapacitors (ESCs) in type I and type III configurations. In type I ESCs, PBEDOT-iI provides a specific power of ∼360 W/kg and specific energy of ∼0.5 Wh/kg, while retaining about 80% of its electroactivity over 10 000 cycles. In addition, we report on the use of PBEDOT-iI in type III supercapacitors where operating voltages as high as 2.5 V were achieved with specific energies of ca. 15 Wh/kg, albeit with limited stability.

Recent advances in conjugated polymer energy storage

“…18 There has been much work on p-type materials for cathodes, but there has been little focus on the synthesis of new n-type materials. [46][47][48] For fully flexible polymer batteries to be realized, both electrodes should be plastic, and so there is a need to research new n-type electrode materials as well.…”

“…12,69,196 The Reynolds group has circumvented the poor polymerizability of n-type monomers by sandwiching an electron poor n-type heterocycle between two electron rich heterocycles to form a donor-acceptor polymer. 47,197 These n-dopable polymers were examined in symmetric supercapacitors using non-aqueous electrolyte. It was found these devices could attain operating voltages as high as 2.5 V and energy densities of $13 Wh/kg although they experienced a loss of electrochemical activity after 200 cycles.…”

“…It was found these devices could attain operating voltages as high as 2.5 V and energy densities of $13 Wh/kg although they experienced a loss of electrochemical activity after 200 cycles. 47 Diffusion limitations lead to low response times at high current densities, leading to low power efficiencies. So-called ''self-doped'' conjugated polymers possessing ionic side chains can have very fast response times and improved processability relative to their parent polymers, but can suffer from low conductivities.…”

Synthesis of Small Band Gap Poly[Bis-EDOT-Isoindigo] via Direct Arylation and Oxidative Electropolymerization, and Its Optoelectronic Properties

“…2 Furthermore, donor-acceptor O-conjugated copolymers based on 3,4-ethylenedioxythiophene, EDOT, and isoindigo units offer stable and good electrochemical supercapacitors. 3 Thus, development for the effective synthetic method of isoindigo-based O-conjugated polymer is of great interest for various applications.…”

“…Oxidative homo-coupling reactions of arenes such as thiophenes using stoichiometric or excess amount of metal-reagents (ex. FeCl 3 and Ni(COD) 2 ) for monomers are very efficient to give Oconjugated polymers, but metal by-products are formed. 4,5 On the other hand, Pd-catalyzed cross-coupling reactions of various bromoarenes with organometallic monomers have contributed to the efficient synthesis of various O-conjugated polymers.…”