Synthesis, characterization, electrical and dielectric studies of AgCuI and Co-SnO2 composite solid electrolytes

•The SCI–CDS composites were characterized by XRD, Far IR and SEM.•Conductivity reached 1.29 × 10−4 S/cm at room temperature for x = 0.4 composition.•The value of dielectric constant decreases with the increase of frequency.

The composite solid electrolytes of AgCuI (SCI) and Co-SnO2 (CDS) were prepared by direct mixing method. The phase structure, composition and surface morphology of the composites were explained by X-ray diffraction (XRD), Far infrared spectroscopy (Far IR) and Scanning electron microscopy (SEM). AC impedance spectroscopy revealed that the ionic conductivity was effectively increased with the increase of temperature. Presence of a semicircle in the impedance spectra shows the greater contribution of grain than the grain boundary. Addition of CDS particles enhanced the ionic conductivity of the composites, reached a maximum value σ = 1.29 × 10−4 S cm−1 at room temperature for x = 0.4 composition. The dielectric values of the composite were gradually increased upon increasing the temperature, followed by a sharp change observed at 440 K. The electrical modulus of the sample was decreased with the increase of temperature and exhibits a single relaxation.

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