title: Understanding Voltage Decay in Lithium-Rich Manganese-Based Layered Cathode Materials by Limiting Cutoff Voltage.
abstract: The effect of the cutoff voltages on the working voltage decay and cyclability of the lithium-rich manganese-based layered cathode (LRMO) was investigated by electrochemical measurements, electrochemical impedance spectroscopy, ex situ X-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy line scan technologies. It was found that both lower (2.0 V) and upper (4.8 V) cutoff voltages cause severe voltage decay with cycling due to formation of the spinel phase and migration of the transition metals inside the particles. Appropriate cutoff voltage between 2.8 and 4.4 V can effectively inhibit structural variation as the electrode demonstrates 92% capacity retention and indiscernible working voltage decay over 430 cycles. The results also show that phase transformation not only on high charge voltage but also on low discharge voltage should be addressed to obtain highly stable LRMO materials.
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Jingsong
authors.initials: J
authors.lastname: Yang
authors.affiliation: College of Chemistry, Central China Normal University , Wuhan 430079, China.
authors.forename: Lifen
authors.initials: L
authors.lastname: Xiao
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Jiangwei
authors.initials: J
authors.lastname: Fan
authors.affiliation: School of Power and Mechanical Engineering, Wuhan University , Wuhan 430072, China.
authors.forename: Zhongxue
authors.initials: Z
authors.lastname: Chen
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Xinping
authors.initials: X
authors.lastname: Ai
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Hanxi
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Chemistry and Molecular Science, Hubei Key Laboratory of Electrochemical Power Sources, Wuhan University , Wuhan 430072, China.
authors.forename: Yuliang
authors.initials: Y
authors.lastname: Cao
keywords: cathode material; limiting cutoff voltage; lithium-ion battery; lithium-rich manganese-based layered oxide; voltage decay