Copyright © 2018 Sandeep Srivastava, Pradeep K. Varshney. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. International Journal of Engineering & Technology, 7 (2) (2018) 887-890 International Journal of Engineering & Technology Website: www.sciencepubco.com/index.php/IJET doi: 10.14419/ijet.v7i2.12423 Research paper Conductivity and structural studies of PVA based mixed-ion composite polymer electrolytes Sandeep Srivastava 1 *, Pradeep K. Varshney 2 1 Department of Physics, Faculty of Engineering & Technology, Manav Rachna International Institute of Research and Studies, Faridabad, Haryana, India 2 Department of Chemistry, Faculty of Engineering & Technology, Manav Rachna International Institute of Research and Studies, Faridabad, Haryana, India *Corresponding author E-mail: sandeepsri1973@gmail.com Abstract The solid membranes having different ratios of poly-vinyl alcohol (PVA), sodium perchlorate (NaClO4) and lithium perchlorate (LiClO4) were prepared using solution casting technique. The mixed-ion composite polymer electrolytes were characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and conductivity measurement investigations. The XRD study confirms the amorphous nature of the mixed-ion composite polymer electrolytes. FTIR analysis has been used to characterize the structure of pol- ymer which confirms the polymer and salt complex formation. The temperature dependent nature of ionic conductivity of the mixed-ion composite polymer electrolytes was determined by using conductivity meter (EC-035WP ERMA Inc, made in Japan). The ionic conduc- tivity of the electrolyte was found in the range of 10 -3 - 10 -4 S/cm at room temperature. Keywords: FTIR; Ionic Conductivity; Mixed-Ion Composite Polymer Electrolyte; XRD. 1. Introduction The application of solid polymer electrolytes in electrochemical storage devices, super capacitors, fuel cells and sensors are in- creasing day by day since last few decades [1-4]. Extensive stud- ies and research have been committed towards improvement in conductivity of solid polymer electrolyte materials at ambient temperature for their potential application in electrochemical de- vices. Several modifications such as incorporation of various salts [5-11], plasticizers [12-14] and fillers [15-16] in solid polymer electrolytes have been explored to improve their performance in electrochemical device applications. The exploration of new mate- rials has been done during the past few decades that can replace the conventional materials with improved characteristics. The mixed ion composite polymers are fulfilling the requirements of such materials in modern era. The mixed-ion composite polymers are produced by combination of two or more components and are heterogeneous on microscopic scale [9-10]. The present work aims at the introduction of an economical mixed-ion composite polymer material which can be used in elec- trochemical devices with good performance comparable with pre- sent electrolytes of mixed-ion nature. This paper gives an account of crystallization character, structural analysis and ionic conduc- tion of the new mixed-ion composites of PVA with inorganic salts. 2. Materials and method 2.1. Experimental Poly (vinyl alcohol) PVA (molecular weight = 1,25,000) was pur- chased from CDH, sodium perchlorate (NaClO4) and lithium per- chlorate (LiClO 4 ) were purchased from Sigma Aldrich. Weighing of polymers and salts was done on Toledo Metller electronic bal- ance. The stock solutions of sodium perchlorate (NaClO4) and lithium perchlorate (LiClO 4 ) were prepared and later used to prepare dif- ferent mixed ion composite polymer electrolytes. The salts were added to the polymer in various concentrations (5%, 10%, 15%, 20%, 25% and 30% w/v) to make composites of different compo- sitions. The solutions of electrolytes were prepared by mixing of PVA (20%) with NaClO4 and LiClO 4 at different ratios in distilled wa- ter to get PVA+NaClO4, PVA+LiClO4 and PVA+NaClO4+LiClO4 complex electrolytes. The solutions were then stirred continu- ously using stirrer for 8 hours on a hot plate at 60º C to obtain a homogeneous mixture. Finally, prepared solutions of mixed ion composites were placed in 80 × 15 mm diameter Borosil petri dishes for further annealing at room temperature. The petri dishes were covered with aluminium foil to avoid any contamination from environment. Five different samples of polymer electrolytes were prepared and subjected to characterization. 2.2. Characterization techniques Temperature dependent conductivity of the samples was measured by pen type conductivity meter (EC-035WP ERMA Inc, made in Japan) at varying temperatures. Mixed-ion composite polymer electrolyte samples of 1 mm thickness and 10 mm × 10 mm di- mension were placed between the electrodes of conductivity me- ter. The thicknesses of samples were measured by screw gauge.