Structural, thermal and electrochemical studies of PVA/PVP-NH4SCN-[C2C1Im][SCN] polymer electrolyte system

The paper reports preparation and characterization of a proton conducting polymer electrolyte system comprising a blend of poly(vinylalcohol) (PVA) and poly(vinylpyrrolidone) (PVP) and liquid electrolyte of ammonium thiocyanate (NH4SCN) in the ionic liquid 1-Ethyl-3-methylimidazolium thiocyanate [C(2)C(1)Im][SCN]. The well-known solution cast technique has been used to prepare films of the blend polymer electrolyte. The films have been characterized using FTIR and Raman spectroscopy, X-ray diffraction, DSC/TGA, complex impedance spectroscopy and cyclic voltammetry. The liquid electrolyte has been found to form complex with the polymer blend system. The electrolyte system has been observed to possess very small crystallinity. The melting point of the electrolyte has been found to be 121 degrees C for the highest conducting composition. The ionic conductivity of the films has been observed to be similar to 10(-2) S cm(-1) at room temperature. The temperature dependence of ionic conductivity of the blend electrolyte shows VTF behavior. The ion conduction has been investigated with the help of dielectric behavior of the electrolyte membrane. The paper also reports confirmation of protonic conduction in the electrolyte using complex impedance spectroscopy and cyclic voltammetry.

Automated summary

The paper describes the preparation and characterization of a proton conducting polymer electrolyte system consisting of a blend of PVA and PVP, as well as liquid electrolyte of NH4SCN in the ionic liquid [C(2)C(1)Im][SCN]. The study found that the liquid electrolyte forms a complex with the polymer blend and the system possesses very small crystallinity, with an ionic conductivity of around 10^(-2) S cm^(-1) at room temperature, showing VTF behavior in temperature dependence. Protonic conduction in the electrolyte was confirmed using complex impedance spectroscopy and cyclic voltammetry.