High conducting poly(vinyl alcohol)–ionic liquid based electrolytes for electric double layer capacitors (EDLCS) application / Liew Chiam Wen
PVA/ammonium acetate (CH3COONH4)–based polymer electrolytes had been prepared using solution casting technique. The effect of addition of ionic liquid onto polymer electrolytes is investigated throughout this project. Three different types of ionic liquids are added into the PVA/ammonium acetate...
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Format: | Thesis |
Published: |
2015
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Online Access: | http://studentsrepo.um.edu.my/6496/1/Appendix.pdf http://studentsrepo.um.edu.my/6496/2/Front_cover.pdf http://studentsrepo.um.edu.my/6496/3/Preface.pdf http://studentsrepo.um.edu.my/6496/4/References.pdf http://studentsrepo.um.edu.my/6496/5/Thesis.pdf http://studentsrepo.um.edu.my/6496/6/Title_page.pdf http://studentsrepo.um.edu.my/6496/ |
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Summary: | PVA/ammonium acetate (CH3COONH4)–based polymer electrolytes had been prepared
using solution casting technique. The effect of addition of ionic liquid onto polymer
electrolytes is investigated throughout this project. Three different types of ionic liquids
are added into the PVA/ammonium acetate (CH3COONH4)–based polymer electrolytes
that are 1–butyl–3–methylimidazolium chloride (BmImCl), 1–butyl–3–
methylimidazolium bromide (BmImBr) and 1–butyl–3–methylimidazolium iodide
(BmImI). The ionic conductivity of polymer electrolyte is increased about two orders of
magnitude from (1.94±0.01)×10-5 S cm-1 to (8.97±0.01) mS cm-1, (9.29±0.01) mS cm-1
and (9.63±0.01) mS cm-1 upon addition of 50 wt.% of BmImCl, 60 wt.% of BmImBr and
70 wt.% of BmImI, respectively at ambient temperature. All the polymer electrolytes
follow Vogel–Tamman–Fulcher (VTF) relationship which is associated with free volume
theory. The complexation between PVA, CH3COONH4 and ionic liquids is proven in
Fourier Transform Infrared (FTIR) studies. Addition of ionic liquids reduces the glass
transition temperature (Tg) of polymer electrolytes as proven in differential scanning
calorimetry (DSC), improves the thermal stability of polymer electrolytes as shown in
thermogravimetric analysis (TGA) and widens the electrochemical potential window of
polymer electrolytes as shown in linear sweep voltammetry (LSV). The crystallinity of
polymer electrolytes and the coherence length of crystallites are determined in X–ray
diffraction (XRD) studies. Electric double layer capacitors (EDLCs) are assembled using
carbon–based electrodes. The specific capacitance of EDLC containing ionic liquid–
added polymer electrolytes is much higher than the EDLC containing ionic liquid–free
polymer electrolyte. The electrochemical properties of the EDLCs are analyzed using
cyclic voltammetry (CV), low frequency electrochemical impedance spectroscopy (EIS)
and galvanostatic charge–discharge (GCD) studies. |
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