The Effect of Electrode-Electrolyte Interface on the Electrochemical Impedance Spectra for Positive Electrode in Li-Ion Battery. Issue 3 (1st January 2019)

• Record Type: Journal Article
• Authors: Tatara, Ryoichi; Karayaylali, Pinar; Yu, Yang; Zhang, Yirui; Giordano, Livia; Maglia, Filippo; Jung, Roland; Schmidt, Jan Philipp; Lund, Isaac; Shao-Horn, Yang
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 3(2019)
• Page Start: A5090
• Page End: A5098
• Publication Date: 2019-01-01
• Subjects: Batteries - Lithium -- Electrode Kinetics -- EIS -- Electrode-Electrolyte Interface -- Li-ion Batteries; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0121903jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Understanding the effect of electrode-electrolyte interface (EEI) on the kinetics of electrode reaction is critical to design high-energy Li-ion batteries. While electrochemical impedance spectroscopy (EIS) is used widely to examine the kinetics of electrode reaction in Li-ion batteries, ambiguities exist in the physical origin of EIS responses for composite electrodes. In this study, we performed EIS measurement by using a three-electrode cell with a mesh-reference electrode, to avoid the effect of counter electrode impedance and artefactual responses due to asymmetric cell configuration, and composite or oxide-only working electrodes. Here we discuss the detailed assignment of impedance spectra for LiCoO2 as a function of voltage. The high-frequency semicircle was assigned to the impedance associated with ion adsorption and desorption at the electrified interface while the low-frequency semicircle was related to the charge transfer impedance associated with desolvation/solvation of lithium ions, and lithium ion intercalation/de-intercalation into/from Li x CoO2 . Exposure to higher charging voltages and greater hold time at high voltages led to no significant change for the high-frequency component but greater resistance and greater activation energy for the low-frequency circle. The greater charge transfer impedance was attributed to the growth of EEI layers on the charged Li x CoO2 surface associated with electrolyte oxidation promoted by ethylene carbonate dehydrogenation.