TY - JOUR
T1 - Stable viologen-based electrochromic devices
T2 - Control of Coulombic interaction using multi-functional polymeric ionic liquid membranes
AU - Yu, Hsin Fu
AU - Li, Chun Ting
AU - Ho, Kuo Chuan
N1 - Funding Information:
This work was financially supported by the “ Advanced Research Center of Green Materials Science and Technology ” from the Featured Area Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education ( 110L9006 ) and the Ministry of Science and Technology in Taiwan (MOST 107-2221-E-002-173-MY3 , 108-2221-E-002-112-MY3 , 108-3116-F-002-010-CC2 , and 109-2634-F-002-042 ). This work was also partially supported by the Center for Sustainability Science, Academia Sinica , Taipei, Taiwan, under project number AS–SS–108-02 . The experimental assistance from Mr. Sean Kao, of Taipei American School, is highly appreciated.
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/1/15
Y1 - 2023/1/15
N2 - Newly designed polymeric ionic liquid, poly(vinylidene fluoride-co-difluorovinylidene aminooxoethyl-1-butylimidazolium-co-vinylidene aminooxoethyl-1-butylimidazolium tetrafluoroborate) (denoted as PFI-BF4), were successfully synthesized with an intention to form the stable electrospun membranes as quasi-solid-state electrolytes for the use in the electrochromic devices (ECDs). The fluorine atoms in the PFI-BF4 membranes could restrain viologen from being quenched on the cathode. The incorporation of imidazolium entities in the PFI-BF4 membranes could enhance the electrochemical stability and lower the charge transfer resistance at the electrolyte/cathode interface due to the suppression of viologen which are being trapped on the membranes. With an optimal molar ratio of imidazoliums to fluorines on the PFI-BF4 membranes, the viologens would be nearly free from aggregation since the Coulombic attraction towards fluorines and the Coulombic repulsion towards imidazoliums reach equilibrium. After a systematic investigation, the PFI-BF4_1.5 ECD exhibited a high transmittance change (ΔT) of 73.0%, with an effective coloration efficiency (ηe) of 460 cm2 C-1 at 600 nm and fast response times (bleaching time of 3.9 s and coloring time of 1.7 s). Most importantly, the PFI-BF4_1.5 ECD retained 95.9% and 88.3% of its initial ΔT after 10,000 and 50,000 continuous switching cycles, respectively.
AB - Newly designed polymeric ionic liquid, poly(vinylidene fluoride-co-difluorovinylidene aminooxoethyl-1-butylimidazolium-co-vinylidene aminooxoethyl-1-butylimidazolium tetrafluoroborate) (denoted as PFI-BF4), were successfully synthesized with an intention to form the stable electrospun membranes as quasi-solid-state electrolytes for the use in the electrochromic devices (ECDs). The fluorine atoms in the PFI-BF4 membranes could restrain viologen from being quenched on the cathode. The incorporation of imidazolium entities in the PFI-BF4 membranes could enhance the electrochemical stability and lower the charge transfer resistance at the electrolyte/cathode interface due to the suppression of viologen which are being trapped on the membranes. With an optimal molar ratio of imidazoliums to fluorines on the PFI-BF4 membranes, the viologens would be nearly free from aggregation since the Coulombic attraction towards fluorines and the Coulombic repulsion towards imidazoliums reach equilibrium. After a systematic investigation, the PFI-BF4_1.5 ECD exhibited a high transmittance change (ΔT) of 73.0%, with an effective coloration efficiency (ηe) of 460 cm2 C-1 at 600 nm and fast response times (bleaching time of 3.9 s and coloring time of 1.7 s). Most importantly, the PFI-BF4_1.5 ECD retained 95.9% and 88.3% of its initial ΔT after 10,000 and 50,000 continuous switching cycles, respectively.
KW - Electrochromism
KW - Electrospinning
KW - Membrane
KW - Polymeric ionic liquid
KW - Viologen
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U2 - 10.1016/j.solmat.2022.112072
DO - 10.1016/j.solmat.2022.112072
M3 - Article
AN - SCOPUS:85140477455
SN - 0927-0248
VL - 250
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
M1 - 112072
ER -