Highly Stable Indacenodithieno[3,2- b]thiophene-Based Donor-Acceptor Copolymers for Hybrid Electrochromic and Energy Storage Applications

Petri Murto; Sait Elmas; Ulises A Méndez-Romero; Yanting Yin; Zewdneh Genene; Mariza Mone; Gunther G Andersson; Mats R Andersson; Ergang Wang

doi:10.1021/acs.macromol.0c02212

Highly Stable Indacenodithieno[3,2- b]thiophene-Based Donor-Acceptor Copolymers for Hybrid Electrochromic and Energy Storage Applications

Macromolecules. 2020 Dec 22;53(24):11106-11119. doi: 10.1021/acs.macromol.0c02212. Epub 2020 Dec 11.

Authors

Petri Murto^{1

2

3}, Sait Elmas², Ulises A Méndez-Romero^{1

4}, Yanting Yin², Zewdneh Genene¹, Mariza Mone^{1

2}, Gunther G Andersson², Mats R Andersson², Ergang Wang^{1

5}

Affiliations

¹ Department of Chemistry and Chemical Engineering/Applied Chemistry, Chalmers University of Technology, Gothenburg SE-412 96, Sweden.
² Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, South Australia 5042, Australia.
³ Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
⁴ Centro de Investigación en Materiales Avanzados S.C. (CIMAV), Unidad Monterrey, Alianza Norte 202, Parque PIIT, Apodaca, Nuevo León 66628, Mexico.
⁵ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.

Abstract

Stable doping of indacenodithieno[3,2-b]thiophene (IDTT) structures enables easy color tuning and significant improvement in the charge storage capacity of electrochromic polymers, making use of their full potential as electrochromic supercapacitors and in other emerging hybrid applications. Here, the IDTT structure is copolymerized with four different donor-acceptor-donor (DAD) units, with subtle changes in their electron-donating and electron-withdrawing characters, so as to obtain four different donor-acceptor copolymers. The polymers attain important form factor requirements for electrochromic supercapacitors: desired switching between achromatic black and transparent states (L*a*b* 45.9, -3.1, -4.2/86.7, -2.2, and -2.7 for PIDTT-TBT), high optical contrast (72% for PIDTT-TBzT), and excellent electrochemical redox stability (I^red/I^ox ca. 1.0 for PIDTT-EBE). Poly[indacenodithieno[3,2-b]thiophene-2,8-diyl-alt-4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-(2-hexyldecyl)-2H-benzo[d][1,2,3]triazole-7,7'-diyl] (PIDTT-EBzE) stands out as delivering simultaneously a high contrast (69%) and doping level (>100%) and specific capacitance (260 F g^-1). This work introduces IDTT-based polymers as bifunctional electro-optical materials for potential use in color-tailored, color-indicating, and self-regulating smart energy systems.