Muthuvinayagam Muthiah

Polymer blend electrolytes are prepared by blending three polymers—Polyvinyl alcohol:Polyvinyl pyrrolydone:Polyethylene glycol ( PVA ∶ PVP ∶ PEG ) with the addition of inorganic salt sodium nitrate ( NaNO 3 )—by using a solution casting technique. X-ray diffraction (XRD) is used to confirm that the produced polymer electrolytes are amorphous. Fourier transform infrared spectroscopy (FTIR) analysis is used to determine the complexation and chemical bonding between the electrolytes’ salt and polymers. The morphology of the polymer electrolytes is verified using scanning electron microscopy (SEM). From impedance studies, the ionic conductivity and activation energy of the electrolytes are evaluated. The maximum ionic conductivity and minimum relaxation time is observed for the PVA / PVP / PEG / NaNO 3 ( 40 ∶ 40 ∶ 20 ∶ 10    mw % ) system. The higher conducting polymer electrolyte has low activation energy that enhances ionic conductivity through the polymer matrix. Temperature-dependent Arrhenius behavior is observed for all prepared polymer electrolytes. It is proved that ionic conductivity of the films increases with salt concentration up to a limit. It is discovered that the optimized higher conducting electrolyte has a higher dielectric constant and dielectric loss. The low bandgap of the higher conducting polymer electrolyte has been demonstrated. Transference number studies demonstrated that the polymer electrolytes are effective ionic conductors. A sodium battery with good rechargeability has been fabricated using the higher conductivity polymer electrolyte.

A sustainable and environmentally friendly approach was used in the development of Solid Biopolymer Electrolyte (SBE), which derived from natural polymers resources. In this study, cellulose-based electrolyte system consists of 2-hydroxyethyl cellulose (2HEC) doped with ammonium thiocyanate (ATC) was further improved by adding polyethylene glycol (PEG) as a plasticiser. The SBE was fabricated via solution casting technique. The addition of PEG into the system remarkably enhanced ionic conductivity up to 1.76 × 10– ³ S·cm– ¹ at 8 wt.% of PEG, showing an improvement in ion mobility. Electrical properties were investigated through dielectric studies, confirming the ionic nature of the SBE system and the influence of PEG on relaxation behaviour. Temperature-dependent conductivity measurements showed that the system-maintained performance up to 373 K and followed Arrhenius behaviour. These findings highlight the potential of biopolymerbased electrolytes with plasticisers like PEG for sustainable, simple, and environmentally friendly solid-state energy storage applications while demonstrating the importance of material design in achieving high ionic conductivity and thermal stability.

In the present work, the Physico-chemical properties of Artocarpus Heterophyllus(AH) was investigated. The properties of the prepared samples were characterized using SEM, XRD, FTIR and Tensile strength analysis. The core part of Artocarpus Heterophyllus fiber is alkali treated and its characteristic have been analyzed for raw and alkali treated. This characteristic study reveals that the fiber can be extensively used as a good reinforcement for composite materials through its characteristic study. The result of XRD analysis show the crystallite size of the alkali treated fiber is high and similar in comparison with raw fiber. The mechanical strength of the fiber is increased due to alkali treatment. The SEM analysis shows the presence of impurities at the surface and it has been removed by alkali treatment. .FTIR spectroscopy showed the various functional groups with strong absorption bands, available in the core part of AH fiber. The maximum improvement of tensile strength and Young’s modulus was observed in alkali treated fiber.

Solid biodegradable polymer blend electrolytes have been prepared along with magnesium nitrate salt using solution casting technique. The X-ray diffraction analysis confirms the increase in amorphous nature of the prepared polymer electrolytes by blending PVDF-HFP with starch. The FTIR spectra reveal the various vibrational frequencies of hydroxyl, carbonyl and carboxyl group of polymer electrolytes. The maximum ionic conductivity value is observed for 15% of magnesium nitrate doped system at ambient temperature. Thermal studies are also carried out for higher conducting film from room temperature to 600˚C to determine glass transition temperature and decomposition temperature of the electrolyte. Electrochemical measurements have been performed for higher conducting electrolyte to determine the electrochemical behaviour. It shows the potential window of -0.5 to 0.4 V with equal range of oxidation and reduction peaks that confirms the pseudo-capacitive nature. The charge–discharge studies are observed with current range from 0.2-2 mA and these results indicate the prepared biopolymer electrolytes are suitable for energy storage applications.