Investigation of blend biopolymer electrolytes based on Dextran-PVA with ammonium thiocyanate

• Published in: Journal of solid state electrochemistry 2021-03, Vol.25 (3), p.755-765
• Main Authors: Maheshwari, T., Tamilarasan, K., Selvasekarapandian, S., Chitra, R., Kiruthika, S.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Biopolymers; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex formation; Condensed Matter Physics; Conducting polymers; Dextrans; Distilled water; Electrochemistry; Electrolytes; Energy Storage; Fourier transforms; Glass transition temperature; Impedance; Infrared spectroscopy; Ion currents; Membranes; Open circuit voltage; Original Paper; Physical Chemistry; Polymers; Thiocyanates; X-ray diffraction
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-020-04850-5

A new polymer electrolytes based on Dextran, poly vinyl alcohol (PVA) with different concentrations of ammonium thiocyanate (NH 4 SCN) have been prepared by solution casting technique using distilled water as a solvent. The synthesized biopolymer membranes have been characterized by various techniques such as X-ray diffraction (XRD), Fourier transform–infrared spectroscopy (FTIR), differential scanning calorimetric (DSC), AC impedance, linear sweep voltammetry (LSV), and transference number measurement. The increase in amorphous nature of the blend polymer (700 mgDextran:300 mgPVA) with increase in salt concentration is observed in XRD pattern. The complex formation between the blend polymer and salt has been confirmed by FTIR. The glass transition temperature ( T g ) of the prepared polymer membranes have been analyzed by DSC. From AC impedance analysis, a maximum ionic conductivity of 8.03 × 10 −3  S/cm has been achieved by incorporation of 0.6 M.wt% NH 4 SCN with blend polymer (700 mgDextran:300 mgPVA). The electrochemical stability of the highest conducting polymer electrolyte 700 mgDextran:300 mgPVA:0.6 M.wt%NH 4 SCN has been observed as 3.01 V by LSV. From Wagner’s polarization method, transference number has been calculated. The proton battery has been constructed with the highest conducting polymer electrolyte 700 mgDextran:300 mgPVA:0.6 M.wt%NH 4 SCN. The open-circuit voltage (OCV) has been observed as 1.75 V and the battery performance is studied.