Synthesis and characteristics of polyurethane acrylate gel polymer electrolyte for dye sensitized solar cell application
Solid and liquid electrolytes pose opposing advantages and disadvantages. Solid electrolyte has lower electrochemical performance in terms of ionic conductivity but has wide operating temperatures. However, liquid electrolyte has greater electrochemical performance but they easily leak and corrod...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/99738/1/CHAI%20KAI%20LING%20-%20IR3.pdf |
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| Summary: | Solid and liquid electrolytes pose opposing advantages and disadvantages.
Solid electrolyte has lower electrochemical performance in terms of ionic
conductivity but has wide operating temperatures. However, liquid electrolyte
has greater electrochemical performance but they easily leak and corrode
components that come into contact with it. Gel polymer electrolyte (GPE) aims
to combine the advantages of both solid and liquid electrolyte in one single
package. In this work, dye sensitized solar cells (DSSCs) was fabricated from
polyurethane acrylate (PUA) GPE which have been enhanced with varying
amounts of (i) tetrabutylammonium iodide (TBAI), (ii) TBAI and lithium iodide (LiI)
and (iii) TBAI, LiI and 1-butyl-3-methylimidazolium ionic liquid (BMII). The PUA
was characterised using wet chemical tests such as Oxirane Oxygen Content
test, Acid value test, Hydroxyl value test and Iodine Value test. Furthermore, the
PUA was characterised by FTIR (Fourier Transform Infrared spectroscopy) and
EIS (Electrochemical Impedance Spectroscopy). With the FTIR spectrum, it
proved that PUA was successfully synthesized by epoxidation, hydroxylation and
introduction of isocyanate group processes. Based on the Nyquist plot of pure
PUA, the ionic conductivity (σ) obtained was 5.60 × 10-6 S cm-1. The PUA
polymer was enhanced with various iodide salts to increase its electrochemical
performance. All GPE systems prepared were characterised using FTIR, thermal
gravimetric analysis (TGA) and EIS. PUA were prepared with TBAI salt as the
first GPE system. FTIR was performed to determine the formation of
complexation between PUA and TBAI salt. It was observed that 30 wt. % TBAI
salt (A3 electrolyte) shows the highest σ of 1.88×10-4 S cm-1 with the highest
charge mobility (μ) of 6.24×10-7 cm2 V-1 s-1 and diffusion coefficient (D) of
1.60×10-8 cm2 s-1 which estimated from fitting the Nyquist plots. The A3
electrolyte recorded the highest solar conversion efficiency (η) of 1.97 %. The
highest η was due to low charge transfer resistance (Rpt) of 2.54 Ω at the
electrolyte/counter electrode interface along with low charge transfer resistance
(Rct) of 24.97 Ω at TiO2/dye/electrolyte interface and the charge diffusion resistance (Rd) of 34.14 Ω in the redox electrolyte. This A3 electrolyte was then
further enhanced with the addition of LiI and was observed that 5.00 wt. % LiI
(B2 electrolyte) shows the best result. B2 electrolyte shows the maximum σ of
2.34×10-4 S cm-1. This was because B2 electrolyte had the highest μ of 1.65×10-
6 cm2 V-1 s-1 and D of 4.25×10-8 cm2 s-1. B2 electrolyte indicated the highest η of
5.09 % due to low value of Rpt, Rct and Rd. B2 electrolyte then further enhanced
with the addition of BMII ionic liquid and 6 wt. % BMII (C3 electrolyte) shows the
best result. The C3 electrolyte manages to achieve an ionic conductivity value of
4.17 ×10-4 Scm-1 with highest μ of 2.03×10-6 cm2 V-1 s-1 and D of 5.20×10-8 cm2
s-1. 5.72 % of η obtained with low Rpt, Rct and Rd. This work shows that PUAbased
electrolytes have the potential for DSSC applications. |
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