Understanding Voltage Decay in Lithium-Rich Manganese-Based Layered Cathode Materials by Limiting Cutoff Voltage

作者：Yang, Jingsong; Xiao, Lifen; He, Wei; Fam, Jiangwei; Chen, Zhongxue^*; Ai, Xinping; Yang, Hanxi; Cao, Yuliang^*

来源：ACS Applied Materials & Interfaces, 2016, 8(29): 18867-18877.

DOI：10.1021/acsami.6b04849

• lithium-rich manganese-based layered oxide
• cathode material
• voltage decay
• limiting cutoff voltage
• lithium-ion battery

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.

• 出版日期2016-7-27
• 单位华中师范大学; 武汉大学