(湖南人文科技學院 化學與材料科學系，婁底 417000)
摘 要: 采用液相共沉淀方法合成鋰離子電池用Li(Ni3/8Co3/8Mn2/8)O2正極材料，以XRD、SEM、原子吸收光譜法和電池充放電循環(huán)測試方法表征Li(Ni3/8Co3/8Mn2/8)O2粉末的結構和性能。結果表明：900 ℃焙燒10 h合成的Li(Ni3/8Co3/8Mn2/8)O2粉末樣品具有較好的綜合電化學性能和良好的六角層狀結構，陽離子混合度小，六角晶格有序性高，顆粒為由小晶粒結合而成的多晶體，平均粒徑約為4.5 μm，I003/I104為1.25，R值為0.48，首次放電容量為172.9 mA·h/g(2.8~4.5 V, 0.1C倍率)，0.2C倍率循環(huán)20次后電容量為首次循環(huán)放電容量的96.1%。
關鍵字: 鋰離子電池；正極材料；氫氧化物共沉淀；電化學性能
（Department of Chemistry and Material Science, Hunan Institute of Humanities, Science and Technology, Loudi 417000, China）
Abstract:The layered Li(Ni3/8Co3/8Mn2/8)O2 cathode material for lithium ion batteries was synthesized by hydroxide co-precipitation method. The structure and electrochemical properties of Li(Ni3/8Co3/8Mn2/8)O2 were characterized by X-ray diffractometry, scanning electron microscopy, atomic absorption spectroscopy, and galvanostatic charge-discharge cycling. The results show that Li(Ni3/8Co3/8Mn2/8)O2 powder sample synthesized at 900 ℃ for 10 h reveals good intergration electrochemical properties and well-ordered hexagonal layered structure with low cation mixing. The value of I003/I104 is 1.25. The value of R is 0.48. The particles with 4.5 µm size can be identified from SEM observations. The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 cathode is 172.9 mA·h/g in the voltage range of 2.8−4.5 V at 30 ℃ and 1C, and the initial capacity maintains 96.1% after 20 charge-discharge cycles at 0.2C.
Key words: lithium ion batteries; cathode material; hydroxide co-precipitation; electrochemical performance
