A strategy of constructing spherical core-shell structure of Li1.2Ni0.2Mn0.O2@Li1.2Ni0.4Mn0.4O2 cathode material for high-performance lithium-ion batteries

作者：Chong, Shaokun; Wu, Yifang; Chen, Yuanzhen; Shu, Chengyong; Liu, Yongning^*

来源：Journal of Power Sources, 2017, 356: 153-162.

DOI：10.1016/j.jpowsour.2017.04.081

• Lithium-ion battery
• Cathode material
• Core-shell structure
• Capacity fading
• Voltage decay

Serious decay of capacity and voltage for Li-rich layered cathode materials restrict their commercial application for Li-ion batteries. In this paper, a spherical core-shell structure, Li1.2Ni0.2Mn0.4O2@Li1.2Ni0.4Mn0.4O2 was in-situ prepared using hydrothermal method. SEM images as well as the analysis with XPS and EDS verified that the core-shell structure grows well. Electrochemical properties showed that the merits of the both materials have been preserved for high capacity of core material and high voltage as well as superior cycling stability of shell material. C/S-1/1 sample, whose mass proportion of core to shell is 1:1, exhibits the initial discharge capacity Of 218 mAh.g(-1) with the highest operating voltage of 3.763 Vat 0.1C between 2.0 and 4.8 V, splendid cycling stability with the capacity retention of 93.1% and high voltage retention value of 3.335 V after 100 cycles. The improvement of electrochemical performances are attributed to the stable Li1.2Ni0.4Mn0.4O2 protective shell, which is beneficial to improve the electrochemical kinetics, mitigate the morphology evolution and retard the layered-spinel phase transition by restraining the release of O-2 and weakening the electrode-electrolyte interfacial reaction.

• 出版日期2017-6-15
• 单位西安交通大学; 西北有色金属研究院