Electrochemical impedance spectroscopic characterization on nano-sized Ca3Co3FeO9 electrode with enhanced capacity retention

Abstract

A Ca 3 Co 3 FeO 9 electrode exhibiting enhanced cycle-life performance compared to that of Co 3 O 4 was presented in this study. In order to examine the mechanism of the improved capacity retention in the Ca 3 Co 3 FeO 9 electrode, the cycling-induced variation of electrode kinetics was observed using electrochemical impedance spectroscopy. The separable electrochemical reactions using the appropriate equivalent circuit and the goodnessof-fit results demonstrated the superior charge-transfer kinetics of Ca 3 Co 3 FeO 9 , compared to Co 3 O 4 , during prolonged cycling. These results clearly demonstrated the benefits of the inactive CaO matrix that is spontaneously formed in Ca 3 Co 3 FeO 9 during the first discharge process.

Effects of the Electrolyte Concentration on the Nature of the Solid Electrolyte Interphase of a Lithium Metal Electrode

“…After five cycles, an important decrease of the impedance is observed for both electrolytes, which can be attributed to surface depassivation in the first plating/stripping cycles and the subsequent formation of a new SEI layer. Although the ionic resistances of the electrolytes, that correspond to the first semicircle intercept on Nyquist plots, [ 28,29 ] are very similar for both electrolytes (around 12 Ω) during OCV, the value increases during cycling with the 1 M one. This suggests that, during the plating/stripping cycles, some species are dissolved in the electrolyte leading to a variation of the concentration.…”

Porous Li2C8H4O4 coated with N-doped carbon by using CVD as an anode material for Li-ion batteries

“…The semicircle in the high frequency range was attributed to the SEI passivating lm, and the other semicircle represents the charge transfer process for high-middle frequencies. [23][24][25] An equivalent circuit was used to t these impedance spectra by Zview soware (Fig. 6, inset).…”

Synthesis of cobalt-based layered coordination polymer nanosheets and their application in lithium-ion batteries as anode materials

“…The semicircle in the high frequency range was attributed to the SEI passivating lm, and the other semicircle represents the charge transfer process for high-middle frequencies. [46][47][48] An equivalent circuit model used to t the impedance data is also shown in inset of Fig. 5, and the tted parameters obtained by Zview soware are displayed in Table 1.…”