Investigation of Cathode Electrolyte Interphase Layer in V2O5 Li-ion Battery Cathodes: Time and Potential Effects. Issue 4 (7th April 2021)

• Record Type: Journal Article
• Authors: Dhiman, Rajnish
• Is Part Of: Journal of the Electrochemical Society. Volume 168:Issue 4(2021)
• Publication Date: 2021-04-07
• Subjects: Li-ion battery cathodes -- Li intercalation -- Cathode Electrolyte Interphase -- Vanadium Pentaoxide -- X-ray photoelectron spectroscopy; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/abf17b
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Basic understanding of surface reactions on the Li ion battery electrodes is of great importance as the interphase layers formed on the electrode surface due to the decomposition of electrolyte, during the initial battery cycles affects the safety, cycling life and performance of lithium-ion batteries. The effects of time, potential and cycling rate on the formation of cathode electrolyte interphases (CEIs) have been investigated on a V2 O5 intercalation cathode by X-ray photoelectron spectroscopy (XPS). CEI layer on V2 O5 based cathode is mainly composed of Li-alkyl carbonates (ROCO2 Li), Li2 CO3, LiF and some C−O, C=O species such as polyethylene oxide type compounds, Li-alkoxides (R−CH2OLi) and oxalates. Formation of CEI on cathode takes place during the discharge cycle while a partial dissolution/removal has been observed in the charging cycle. Removal of CEI species during the charging cycle could be ascribed to the puckering of V2 O5 layers due to de-lithiation process. The formation and dissolution of LiF, ROCO2 Li and other species has been observed until ≈215 ± 10 h, this may indicate that the decomposition of electrolyte is taking place till several cycles, which is an undesirable phenomenon in LIBs. CEI formation has shown a dependence on lower discharge potential, time and cycling rate.