Enhanced electrochemical property of FePO_4-coated LiNi_(0.5)Mn_(1.5)O_4 as cathode materials for Li-ion battery

作     者：Ting-Feng Yi Yan-Mei Li Xiao-Ya Li Jing-Jing Pan Qianyu Zhang Yan-Rong Zhu 

作者机构：School of Chemistry and Chemical Engineering Anhui University of Technology Key Laboratory of Metallurgical Emission Reduction & Resources Recycling Ministry of Education Anhui University of Technology School of Environment and Civil Engineering Dongguan University of Technology 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2017年第62卷第14期

页      面：1004-1010页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 

基　　金：supported by the National Natural Science Foundation of China(51404002) Anhui Provincial Natural Science Foundation(1508085MB25) Natural Science Foundation of Guangdong Province(2016A030310127) Anhui Provincial Science Fund for Excellent Young Scholars(gxyqZD2016066) 

主　　题：LiNi0.5Mn1.5O4 FePO4 coating Electrochemical property Lithium ion batteries 

摘      要：Pristine LiNi0.5Mnl.5O4 and FePO4-coated one with Fd-3m space groups were prepared by a sol-gel method. The structure and performance were studied by X-ray diffraction （XRD） rietveld refinement, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM）, energy dispersive spectrometer （EDS） mapping, electrochemical impedance spectroscopy （EIS） and charge- discharge tests, respectively. The lattice parameters of all samples almost remain the same from the Rietveld refinement, revealing that the crystallographic structure has no obvious difference between pris- tine LiNi0.5Mn1.5O4 and FePO4-coated one. All materials show similar morphologies with uniform particle distribution with small particle size, and FePO4 coating does not affect the morphology of LiNi0.5Mnl05O 4 material. EDS mapping and HRTEM show that FePO4 may be successfully wrapped around the surfaces of ***.s04 particles, and provides an effective coating layer between the electrolyte and the surface of LiNi0.5Mn1.5O4 particles. FePO4 （1 wt%）-coated ***.504 cathode shows the highest discharge capac- ity at high rate （2 C） among all samples. After 80 cycles, the reversible discharge capacity of FePO4 （1 wt%） coated LiNi0.5Mn0.5O4 is 117 mAh g^-1, but the pristine one only has 50 mAh g^-1. FeP04 coating is an effec- tive and controllable way to stabilize the LiNi0.5Mn1.5O4/electrolyte interface, and avoids the direct con- tact between LiNi0.5Mn1.5O4 powders and electrolyte, then suppresses the side reactions and enhances the electrochemical performance of the LiNi0.5Mn1.5O4.