Comparison of kinetic properties of LiCoO2 and LiTi0.05Mg0.05Ni0.7Co0.2O2 by impedance spectroscopy

Study of the lithium insertion–deinsertion mechanism in nanocrystalline γ-Fe2O3 electrodes by means of electrochemical impedance spectroscopy

“…10a). It was shown that Q decreased from a value of 7.9 µF.s (ii) Diffusion process -The shape of the capacitive response plotted in the low frequency range was similar to that observed for other insertion materials which have a well known microstructure [29,30,31]. Different theoretical models were developed to understand the diffusion mechanisms and to reach the characteristic parameters involved in the insertion process.…”

Diagnosis of Electrochemical Impedance Spectroscopy in Lithium-Ion Batteries

“…In the past decades, EIS has been extensively used in the analysis of lithium battery systems, especially to predict the behavior of batteries, and to determine the factors limiting the performance of an electrode including its conductivity [75,126], charge-transfer properties [11,103,[117][118][119], properties of the passivating layer, etc. Numerous recent studies have been published on various aspects of the insertion electrodes used in lithium-ion batteries for the attempt to understand the origin of the observed capacity loss during extended cell cycling or storage [1,30,37,52,66,78,97].…”

“…Afterwards, Barsoukov et al [11,12] proposed a new model based on single particles for commercial composite electrode, as shown in Figure 2-3. They supposed that the electrochemical kinetics characteristic of battery materials was represented by several common steps, as shown in Figure 2-4: (i) ionic charge conduction through electrolyte in the pores of the active layer and electronic charge conduction through the conductive part of the active layer; (ii) lithium-ion diffusion through the surface insulating layer of the active material; (iii) electrochemical reaction on the interface of active material particles including electron transfer; (iv) lithium-ion diffusion in the solid phase and (v) phase-transfer in cases where several phases are present and a capacitive behavior that is related to the occupation of lithium ions, which give a semicircle and straight line perpendicular to Z' axis in the Nyquist plot (commonly below 10 -2 Hz), respectively.…”

Electrochemical Properties of LiNi0.8Co0.16Al0.04O2and Surface Modification with Co3(PO4)2as Cathode Materials for Lithium Battery

“…A semicircle located in a high frequency range is attributed to the resistance of the film that covers the surface of the cathode material; a semicircle located in a medium-tolow frequency range is related to charge transfer resistance; and an inclined line is due to Warburg impedance that is associated with lithium diffusion through the oxide electrode. [25][26][27][28] However, the impedance spectrum for bare and coated samples at a pristine state does not display two semicircles; instead, it shows a somewhat depressed one semicircle. It is likely that a semicircle related to surface film resistance was overlapped by a large semicircle associated with charge transfer resistance because the high-frequency semicircle attributable to surface film is generally smaller than the medium-to-low frequency semicircle.…”