摘要
采用溶胶-凝胶法在900!于空气中煅烧合成了层状复合掺杂型正极材料Li(Ni1/3Co1/3Mn1/3)1-2xMgxAlxO2(x=0,0.01,0.02,0.05)。通过X-射线衍射(XRD)、扫描电镜(SEM)和电化学测试等研究了掺杂元素对Li(Ni1/3Co1/3Mn1/3)O2的结构和电化学性能的影响。结果表明,适量Mg、Al掺入Li(Ni1/3Co1/3Mn1/3)O2后降低了材料的阳离子混排程度,且晶胞参数随着掺杂量的增加而增加。合成材料颗粒分布比较均匀,平均粒径约为0.5mm。在充放电倍率为0.1C和电压范围为3.0"4.3V的条件下,与未掺杂样品相比,Mg-Al复合掺杂的样品具有更好的电化学性能和容量保持率。当x#0.02时,复合掺杂样品的首次放电容量和库仑效率分别为153mAh/g和93.0%,20个循环后容量保持率达93.4%。因此Mg-Al复合掺杂锂离子电池正极材料Li(Ni1/3Co1/3Mn1/3)1-2xMgxAlxO2是很有前景的。
The cathode-active materials layered Li（Ni1/3Co1/3Mn1/3）1-2xMgxAlxO2 （ x=0,0.01,0.02,0,05 ） were synthesized by the thermal treatment of the sol-gel precursor at 900 ℃ in air, The influence of Mg-Al co-substitution on the structural and electrochemical properties of Li（Ni1/3Co1/3Mn1/3）O2 was characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM） and electrochemical experiments, The XRD studies show that small amounts of Mg-Al co-doping in Li Li（Ni1/3Co1/3Mn1/3）O2 is significantly to decrease the cation mixing in the layered structure. As the doping content increases, the lattice parameters increase monotonously. The SEM results show that the particle sizes of the samples are distributed uniformly, the average particle size is about 0.5 μm. The Mg-Al co-doped materials show improved cathodic behavior compared to Li（Ni1/3Co1/3Mn1/3）O2 at 0.1 C rate in the voltage range 3.0-4.3 V. The 2% co-doped materials delivers an initial discharge capacity of 153 mAh/g during the first charge and discharge cycle and the first coulombic efficiency is 93.0%, and the capacity retention at the 20＂~ cycle was 93.4%. Therefore, it is a promising method for Mg-Al co-substitution in preparing layered Li（Ni1/3Co1/3Mn1/3）O2 cathode materials of lithium ion battery.
出处
《电源技术》
CAS
CSCD
北大核心
2007年第1期26-29,共4页
Chinese Journal of Power Sources
基金
湖南省重点项目(05GK2015)
教育部重点项目(205109)
湖南省教育厅重点项目(04A054)
