Simulated EIS and Trukhan model to study the ion transport parameters associated with Li+ ion dynamics in CS based polymer blends inserted with lithium nitrate salt

Abstract

In the current work electrical and ion transport parameters of polymer electrolyte (PE) system of chitosan (Ch)/poly(2-oxazoline) (POZ)loaded with various concentrations of lithium nitrate (LiNO3) salt were studied. The EIS analysis shows that the load of LiNO3 improves the conductivity of the PE. The depressed semicircle of EIS which its center is below the Zr-axis and the distribution of relaxation time (τ) of the electrolytes verify the non-Debye behavior of the electrolytes. The maximum conducting system (CSPZLI5) shows the highest conductivity of 1.46 × 10−3 S/cm. Transport parameters (number density (n), mobility (μ), viscosity (η), and diffusion coefficient (D) of ions) are measured by Trukhan and EIS methods and compared agreeably and it is also consistent with the conductivity results. The determined n value from EIS was found to increase from 1.69 × 1016cm−3 to 9.5 × 1019 cm−3. Distinguished areas of stability attributed to DC involvement were marked from AC spectra. Dielectric parameters (i.e. ε' and ε'') are high at the low-frequency (fr) window due to electrode polarization (EP). The loss tangent (tan δ) is used to measure the relaxation time (τ) and ion transport parameters. The τ for the PEs is set off to decrease with increase of LiNO3 amount. The minimum τ of 4.08 × 10−7 s confirms the LiNO3 role in increasing ion migration. The transport parameters (n, μ, D, and η) are also in relationship with the dielectric and impedance analyses. From electric modulus examination it is found that the EP contribution can be minimized and relaxation attributing to bulk effects can be highlighted.

Keywords

• Polymer blends electrolyte
• EIS analysis
• Ion-transport parameters
• Trukhan model
• Electric modulus
• Dielectric analyses