锂离子正极材料Li(Ni_(1/3)Co_(1/3)Mn_(1/3))_(1-x)Al_xO_2的制备及电化学性能

Preparation and Electrochemical Performances of Li(Ni_(1/3)Co_(1/3)Mn_(1/3))_(1-x)Al_xO_2 Cathode Material for Lithium-ion Batteries

以化学法合成Li（Ni1／3Co1／3Mn1／3）1-χAlχO2系列正极材料（0≤x≤O.1）；用x射线衍射仪、扫描电子显微镜和充放电仪研究系列产物的晶体微观结构、表面形貌以及电化学性能，研究不同Al含量参杂对材料性能的影响。结果表明，合成的材料均属于六方晶系，R3m空间群，保持α-NaFeO2层状结构相；Li（Ni1／3Co1／3Mn1／3）1-χAlχO2的首次放电容量166.30mA·h／g，在2.5 ～ 4.5V区间60次循环后比容量衰竭率为4.43％。通过对比Li（Ni1／3Co1/3Mn1／3）0.95Al0.05O2和Li（Ni1／3Co1/3Mn1／3）O2的电极阻抗，分析它们的电化学循环机理，可知掺杂Al后的正极材料适合大倍率放电。

A series of cathode materials Li（Ni1/3Co1/3Mn1/3）1-χAlχO2 （0≤ χ≤0.1） was synthesized by chemical method. The microstructure, surface morphology and electrochemical performance of products synthesized were characterized by X-ray diffraction, scanning electron microscopy and electrochemical techniques. The influence of different mixed AI content on the properties of ceramic materials was studied. The results indicat that the as-prepared i（Ni1/3Co1/3Mn1/3）1-χAlχO2 has a hexagonal α-NaFeO2 structure with a space group of R3m and hexagonal system. Initial discharge capacity of Li （ Ni1/3 Co1/3 Mn1/3 ） 0.95 Al0.05 O2 is 166.30 mA.h/g in the voltage window of 2.5 ～ 4.5 V and shows only 4. 43% reduction after 60 cycles. AC impedance method was adopted to study the electrochemical circulation mechanism of Li（Ni1/3Co1/3Mn1/3）O2 and Li（Ni1/3Co1/3Mn1/3）0.95Al0.05 O2, and Al-coped cathode material is suitable for high rate discharging.