IONIC LIQUID BASED POLYMER ELECTROLYTE FOR ELECTRICAL DOUBLE LAYER CAPACITORS WITH MWCNT ELECTRODES

摘要

In the present studies, poly(ethylene oxide) (PEO) and lithium triflate (LiTf) based polymer-salt complexes (PEO)25:LiCF3SO3 have been prepared added with different wt.% of 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate (EMI triflate or EMITf). A gradual enhancement in room temperature electrical conductivity (up to～3×10-4 S cm-1) has been observed with respect to the addition of ionic liquid (from 0 to 40 wt.%). On further addition of ionic liquid, the electrolyte films were found to be dimensionally unstable. The electrochemical potential window has been substantially enhanced (from 2.4 to 3.0 V), when 40 wt.% of ionic liquid is added. The electrical and electrochemical properties show that the polymer electrolyte is suitable for the electrochemical device applications. Multiwalled carbon nanotubes (MWCNTs)-based all solid-state electric double layer capacitors (EDLCs) have been fabricated and characterized using the optimized ionic liquid based polymer electrolyte. The performance characteristics of the EDLCs have been evaluated by impedance measurements and cyclic voltammetric studies.