Experimental studies on ion conducting polymer electrolytes

Abstract

In past few decades, large number of lithium ion conducting polymer electrolytes was used for the fabrication of electrochemical devices, especially in rechargeable battery. Simultaneously, it is well known fact that the lithium based devices suffers from some major drawbacks; such as quite expensive, sensitive with humidity, explosive in nature and other related problems. In order to overcome these drawbacks, different salts based on sodium, magnesium and zinc ion conducting polymer electrolyte provides a better substitute for lithium ion due to its non-toxicity, cheaper than lithium, natural abundance, environmental friendly nature, high electrochemical reduction potential, comparable ionic radii, high specific energy, more safer than lithium and can be handled safely in oxygen and humid atmospheres. newlineWorldwide efforts are continued to synthesize different types of polymer electrolytes, but still there is a need to optimize its various parameters such as electrical conductivity, low internal resistance, wider potential window etc., for their use in different electrochemical devices like batteries, supercapacitors, fuel cells as a commercial products. newlineThe experimental work reported in the present thesis is devoted towards the studies on sodium ion based polymer blend electrolytes and the ionic liquid based polymer gel electrolytes containing magnesium salts, as an alternative to lithium ion based polymer electrolyte. newlineImpedance spectroscopy technique was used for the optimization and electrical characterization of all the polymeric system in the present work. The electrical conductivity of polymer blend/gel electrolytes are found to be in the order of 10-2 to 10-3 S cm-1 at room temperatures. newlineThe temperature dependence electrical conductivity pattern of polymer blend electrolytes shows the Arrhenius behaviour, whereas; ionic liquid based polymer gel electrolytes system shows the VTF behaviour. newlineThe dielectric properties of the polymeric systems are analyzed using dielectric permittivity, dielectric modulus.