Electrochemical impedance spectroscopy in interfacial studies

Abstract

An important role of the electrochemical impedance spectroscopy (EIS) is the characterization of the electrical double layer formed at the electrode/electrolyte interfaces. The phenomenological double layer studies with an aqueous and ionic liquid electrolytes are reviewed with a conclusion that the double layer capacitance is frequency dependent as the rule rather than the exception. We discuss the impedance consequences of the nonuniform current distribution along the electrochemical interface, which also contributes to the apparent frequency dependence of the capacitance. Finally we show recent articles on nonconventional EIS techniques with high lateral resolution or enabling fast measurements.

Fabrication and Characterization of Hollow Microcapsules from Polyelectrolytes Bearing Thymine Pendant Groups for Ultraviolet‐B (UVB)‐Induced Crosslinking

“…The curves were fitted using the equivalent electrical circuit indicated in the inset of Figure A, where R s represents the ohmic resistance of the electrolyte solution; C dl is the double layer capacitance; R et is the interfacial electron‐transfer resistance corresponding to the redox‐probe electron‐transfer; and finally, the Warburg impedance ( Z W ) that reflects the influence of the diffusion of ions from the bulk electrolyte to the electrode. Only R et and C dl circuit components are expected to depend on the dielectric and insulating features at the electrode/electrolyte interface ,. The calculated R et and C dl values were fluctuating with the charge sign of the outer polyelectrolyte layer on the electrode surface (Figure B), while the R S and the Z W were almost constants (Table S1 of the Supporting Information).…”

“…Figure A shows the Nyquist plots as function of the number of adsorbed polyelectrolyte layers obtained with an equimolar mixture of [Fe(CN) 6 ] 3−/4− as the redox probe couple. In all cases, the Nyquist plots showed the capacitive semicircle at the high‐frequency region related to the charge‐transfer process, followed by a linear response in the low‐frequency range associated with diffusion processes . The curves were fitted using the equivalent electrical circuit indicated in the inset of Figure A, where R s represents the ohmic resistance of the electrolyte solution; C dl is the double layer capacitance; R et is the interfacial electron‐transfer resistance corresponding to the redox‐probe electron‐transfer; and finally, the Warburg impedance ( Z W ) that reflects the influence of the diffusion of ions from the bulk electrolyte to the electrode.…”

“…Only R et and C dl circuit components are expected to depend on the dielectric and insulating features at the electrode/electrolyte interface. [21,22] The calculated R et and C dl values were fluctuating with the charge sign of the outer polyelectrolyte layer on the electrode surface ( Figure 1B), while the R S and the Z W were almost constants (Table S1 of the Supporting Information).…”

Flexible Energy Storage System—An Introductory Review of Textile-Based Flexible Supercapacitors

“…The Bode Plot depicts the absolute impedance |Z| along the changes of frequencies, where the magnitude of |Z| consists of Z and Z according to Equation (5) at a particular frequency. The plot also shows the relationship of the phase angle (θ) between the real part and the imaginary part of impedances, against the change of frequencies, for investigating the changes between these two impedances at different frequencies [100,101].…”

Interdigitated Sensing and Electrochemical Impedance Spectroscopy

“…Electrochemical Impedance Spectroscopy (EIS) is one of the most powerful mechanisms used for sensor investigations as a result of its robust and non-invasive nature (Lasia 2002). Although it is mostly used for characterizing the electrical double layer at the electrode-electrolyte interfaces (Pajkossy and Jurczakowski 2017), the response of the sensors with respect to the change in frequency is also very useful in non-linear processes. EIS is a prominent technique with high resultant sensitivity towards the interfacial phenomenon that is used to analyze the changes in impedance of a cell in the presence of an external source.…”