Characterization of a natural rubber based solid polymer electrolyte to be used for a magnesium rechargeable cell

Demand for solid polymer electrolyte (SPE)s has gone up at an alarming rate during the last decades with the recognition of their suitability for various applications. At present, a considerable attention is focused on natural polymers instead of commercial polymers to improve safety and to reduce cost. This study is based on preparation and characterization of a SPE based on natural rubber (NR) and magnesiumtrifluoromethanesulfonate (MgTF) with the objective of fabricating Mg rechargeable cells. Preparation of the SPE samples was done using solvent casting method. It was possible to obtain thin, mechanically stable films which were white in color. The composition 1 NR: 0.8 MgTF was found to be having the optimum ambient temperature conductivity of 4.41 × 10–3 S cm−1. Sample was purely an ionic conductor having negligible electronic conductivity. The electrochemical stability window was found to be from 0.75 to 2.5 V. This is a quite satisfactory value for applications. Mg ion movement was confirmed using the plating stripping test. Mg rechargeable cells were fabricated successfully with a natural graphite (NG)-based cathode. Its open circuit potential soon after fabrication was about 2.0 V. After a quick drop, it remained constant at 1.7 V. The results obtained are spotlighting the novel features of the study which include value addition to many natural raw materials, low cost and environmental friendliness.