Electrochemical impedance spectroscopy study of AgI–Ag₂O–MoO₃ glasses: understanding the diffusion, relaxation, fragility and power law behaviour

Abstract

Electrochemical Impedance Spectroscopy and Raman studies are performed on fast ion conducting, AgI-Ag 2 O-MoO 3 glasses, over a wide range of composition to understand the features of structure, ion migration and their correlation. These features essentially involve diffusion and relaxation. The coefficients associated with diffusion process, especially, the diffusion coefficient, diffusion length and relaxation time has been determined by applying Nguyen-Breitkopf method. Besides, by tuning the concentration of the constituents, it is possible to obtain samples those exhibit two important structural characteristics: Fragility and Polymeric phase formation. The present study essentially addresses these issues and endeavors to figure out the corroboration among them. The relaxation behavior, when scrutinized in the light of Diffusion Controlled Relaxation model, ascertains the fragility threshold which is also identified as the margin between the two types of polymeric phases. Simultaneously, it fathoms into the equivalent circuitry, its elements and their behavioral changes with above mentioned features.The power law behavior of A.C. conductivity exhibits three different non-Jonscher type dispersive regimes along with a high frequency plateau. The sub-linearity and super-linearity remain significantly below and above the Jonscher's carrier transport limit, 0.5 ≤ n ≤ 0.9. Finally, by observing the behavior of the crossover between these sun-linear and super-linear (SLPL) regime, an intuitive suggestion has been proposed for the appearance of SLPL: oxygen vacancy formation at higher frequency.

Mathematical Modelling of Glyphosate Molecularly Imprinted Polymer-Based Microsensor with Multiple Phenomena

“…The concentration of the redox couple changes in the pores with an exponential gradient. This problem has been addressed in the literature [50,51]. The accumulation of ions on the electrode surface causes an increase in faradic and capacitive current.…”

Electrochemical Impedance Spectroscopy Microsensor Based on Molecularly Imprinted Chitosan Film Grafted on a 4-Aminophenylacetic Acid (CMA) Modified Gold Electrode, for the Sensitive Detection of Glyphosate

“…At high frequencies, the Nyquist plot shows a first semi-circle, while the second is observed at lower frequencies. This element is comprised of contributions from three different processes which are electron transfer process, diffusion control and adsorption of ionic species (Terbouche et al, 2016 ; Tanujit and Asokan, 2019 ).…”

Battery State-of-Health Evaluation for Roadside Energy Storage Systems in Electric Transportation

“…The SOH assessment algorithms can be categorized into model-fitting-and datadriven-based methods. The model-fitting-based methods include internal resistance and open-circuit voltage analysis as well as electrochemical impedance spectroscopy [11], reflected in a set of complex nonlinear equations based on empirical knowledge. The Gaussian process regression models can be used for SOH evaluation.…”