(新疆师范大学 化学化工学院,乌鲁木齐 830054)
摘 要: 运用热处理技术分别制备B2O3、CuO和FePO4包覆的LiMnO2锂离子电池正极材料。采用X射线衍射(XRD)和扫描电镜(SEM)对材料的晶体结构和表观形貌进行分析,通过恒电流充放电以及电化学阻抗技术(EIS)分析其电化学性能。结果表明:包覆后材料的电化学阻抗与Warburge阻抗值有所增大,但包覆能有效抑制正极材料LiMnO2在电化学过程中锰的溶解,改善和提高材料的充放电循环性能和结构的稳定性。
关键字: 层状LiMnO2;锂离子电池;正极材料;表面修饰;电化学性能
LiMnO2 as cathode materials for lithium-ion batteries
(College of Chemistry and Chemical Engineering, Xinjiang Normal University, Urumqi 830054, China)
Abstract:By heat treatment technique, LiMnO2 powders as cathode materials for lithium-ion batteries were coated with B2O3, CuO and FePO4, respectively. The crystal structures and electrochemical properties of those coated LiMnO2 powders were characterized by X-ray diffractometry (XRD) and scanning electron microscopy(SEM). The electrochemical properties of these samples were studied by galvanostatic method. The results show that the electrode of the layered coated-LiMnO2 has better electrochemical properties. The electrochemical impedance experiment shows that Warburge impedance increases slightly for the coated materials. The improvements of electrochemical properties of the surface modified samples are attributed to B2O3 or CuO or FePO4 that inhibits the dissolution of manganese and stabilizes the layered structure of LiMnO2.
Key words: layered LiMnO2; lithium-ion battery; cathode material; surface modification; electrochemical property