Influence of Charge Cutoff Voltage on the Cycling Behavior of LiNi 0.5Mn0.3Co0.2O2 Cathode

Date Published
08/2020
Publication Type
Journal Article
Authors
DOI
10.1149/1945-7111/abaa17
Abstract

Layered oxide, LiNi0.5Mn0.3Co0.2O2 (NMC532), is commonly used in the commercial high energy Li-ion batteries. However, such layered oxide cathode always faces the dilemma between high capacity and stable cycling. Upper charge cutoff voltage is one of the important factors that strongly influences both capacity and cycle life, unfortunately, exhibiting an opposite effect. A choice of an appropriate upper charge cutoff voltage is expected to achieve the balance between these two performance metrics. Therefore, it is of great significance to comprehensively understand the effect of incremental upper voltages, ranging from normally used cutoff voltage to slight overcharge voltage, on the cycling behaviors of the NMC532 cathode material. In this work, the systematic studies about the effect of the upper voltage on the NMC532 cathode material are investigated. Physical characterizations, i.e., ex situ synchrotron X-ray diffraction and X-ray absorption spectroscopy, provide information on the degradation of NMC532 material. Post-mortem analysis via combined scanning electron microscopy and electrochemical impedance spectroscopy reveals the degradation of the cathode-electrolyte-interface at high voltages. This comprehensive study shows the fundamental interplay among many electrochemically relevant factors, especially at different charge cutoff voltages.

Journal
Journal of The Electrochemical Society
Volume
167
Year of Publication
2020
Issue
12
Pagination
120509
Short Title
J. Electrochem. Soc.
Refereed Designation
Refereed
Organizations
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