锂离子电池Li(Ni_(3/8)Co_(3/8)Mn_(2/8))O_2层状正极材料的制备与电化学性能

Synthesis and electrochemical properties of layered Li(Ni_(3/8)Co_(3/8)Mn_(2/8))O_2 cathode material for lithium ion batteries

采用液相共沉淀方法合成锂离子电池用Li（Ni3／8Co3／8Mn2／8）O2正极材料，以XRD、SEM、原子吸收光谱法和电池充放电循环测试方法表征Li（Ni3／8Co3／8Mn2／8）O2粉末的结构和性能。结果表明：900℃焙烧10h合成的Li（Ni3／8Co3／8Mn2／8）O2粉末样品具有较好的综合电化学性能和良好的六角层状结构，阳离子混合度小，六角晶格有序性高，颗粒为由小晶粒结合而成的多晶体，平均粒径约为4．5um，1003／I104为1．25，R值为0．48，首次放电容量为172．9mA·Wg（2．8-4．5V，0．1C倍率），0．2C倍率循环20次后电容量为首次循环放电容量的96．1％。

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 txm size can be identified from SEM observations. The initial discharge capacity of the Li[Nil/3Col/3Mnl/3102 cathode is 172.9 mA.h/g in the voltage range of 2.8-4.5 V at 30 ℃ and 1 C, and the initial capacity maintains 96.1% after 20 charge-discharge cycles at 0.2C.