Executive Summary : | The most famous Li-ion batteries are not ultimate and there are safety issues and problems such as limited and localized Li natural resources. In addition, India share less than 1 percent of global Li resources and there is requirement to become self-reliant in the area of rechargeable secondary battery system. Sodium is earth abundant with terrestrial abundance of 2.6-3.0 % and it is able to provide a potential of -2.7 V with respect of SHE. The sulfur is by product from oil and gas industry and is able to offer discharge capacity of 1672 mA h g-1. In this way, Na-S battery is a promising environment-friendly energy storage option due to low cost, earth abundant materials and theoretically high discharge capacity. The non-availability of a commercial high conducting, non-aqueous electrolyte compatible with sulfur-cathode is a main roadblock in the development of RT Na-S batteries. The fabrication of electrolyte and electrodes with above superior properties can establish RT Na-S battery as a viable energy storage technology for mankind. The published research on these batteries is largely driven by usage of liquid electrolytes due to their inherently high ionic conductivity. These liquid electrolytes tend to leak and cause short-circuiting. The usage of polymer gel electrolytes will be preferred due to enhanced safety, potential to offer good ionic conductivity and its flexibility ensures better electrolyte/electrode interface contact. The very few reports on polymer gel electrolytes for RT Na-S cells have demonstrated poor cycle life due to lesser value of Na+ transport number and incompatibility with chosen electrodes. The usage of nanoparticles is found to enhance liquid retention and better Na+ transport within polymer gel electrolyte. In addition, nanoparticles act as key player in ensuring proper redox-reactions and good electrolyte/electrode interface. The encapsulation of variety of carbon structures within sulfur spheres has shown promising result with liquid electrolytes, however, there are no reports of such encapsulation and RT Na-S performance measurement using polymer gel electrolytes. This research proposal deals with fabrication and characterization of polymer gel electrolyte and sulfur-cathode for Na-S batteries operating at room temperature. The objectives of the present project covers (i) Fabrication and optimization of high performance polymer gel electrolytes using nanoparticles, (ii) Fabrication and optimization of sulfur-cathode using modern architecture such as encapsulation of variety of carbon structures within sulfur spheres and (iii) The fabrication and standardization of RT Na-S batteries on the basis of electrochemical parameters for commercialization The dual approach of fabricating high performance polymer gel electrolytes and sulfur electrodes will be adopted to design prototype RT Na-S batteries. If obtained results on RT Na-S prototype cell are encouraging then patent/commercialization will be attempted. |