FePO4-coated Li[Li0.2Ni0.13Co0.13Mn0.54]O2 with improved cycling performance as cathode material for Li-ion batteries

作     者：Zhong Wang Hua-Quan Lu Yan-Ping Yin Xue-Yi Sun Xiang-Tao Bai Xue-Ling Shen Wei-Dong Zhuang Shi-Gang Lu 

作者机构：R&D Center for Vehicle and Energy Storage General Research Institute of Nonferrous Metals Beijing 100088 China China Automotive Battery Research Institue Co. LtdBeijing 100088 China 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2017年第36卷第11期

页      面：899-904页

核心收录：

学科分类：081702[工学-化学工艺] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：financially supported by the National Nature Science Foundation of China (No.51302017) the National High Technology Research and Development Program of China (No.2012AA110102) the fund from the Science and Technology Commission of Beijing (No.2121100006712002) 

主　　题：Cathodes Charge transfer Coated materials Coatings Crystal structure Electric batteries Electrochemical impedance spectroscopy Electrodes Energy dispersive spectroscopy Field emission cathodes High resolution transmission electron microscopy Lithium Lithium alloys Lithium compounds Manganese Nickel Precipitation (chemical) Scanning electron microscopy Secondary batteries Transmission electron microscopy X ray diffraction 

摘      要：Li[Li0.2Ni0.13Coo.13Mn0.54]O2 cathode materials were synthesized by carbonate-based co-precipitation method, and then, its surface was coated by thin layers of FePO4. The prepared samples were characterized by X-ray diffraction （XRD）, field emission scanning electron micro- scope （FESEM）, energy-dispersive spectroscopy （EDS）, and transmission electron microscopy （TEM）. The XRD and TEM results suggest that both the pristine and the coated materials have a hexagonal layered structure, and the FePO4 coating layer does not make any major change in the crystal structure. The FePO4-coated sample exhibits both improved initial discharge capacity and columbic efficiency compared to the pristine one. More significantly, the FePO4 coating layer has a much positive influence on the cycling perfor- mance. The FePO4-coated sample exhibits capacity reten- tion of 82 % after 100 cycles at 0.5℃ between 2.0 and 4.8 V, while only 28 % for the pristine one at the same charge-discharge condition. The electrochemical impe- dance spectroscopy （EIS） results indicate that this improved cycling performance could be ascribed to the presence of FePO4 on the surface of Li[Li0.2Ni0.13Co0.13Mno.54102 par- ticle, which helps to protect the cathode from chemical attacks by HF and thus suppresses the large increase in charge transfer resistance.