Investigation the electrochemical performance of Li1.2Ni0.2Mn0.6O2 cathode material with ZnAl2O4 coating for lithium ion batteries
Investigation the electrochemical performance of Li1.2Ni0.2Mn0.6O2 cathode material with ZnAl2O4 coating for lithium ion batteries
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DOI：
10.1016/j.jallcom.2016.05.329
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发表时间：
2016-11
影响因子：
6.2
通讯作者：
Yunjian Liu;Zhiqiang Zhang;Yan-bao Fu;Qiliang Wang;Jun Pan;Ming-Ru Su;V. Battaglia
中科院分区：
文献类型：
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作者：
Yunjian Liu;Zhiqiang Zhang;Yan-bao Fu;Qiliang Wang;Jun Pan;Ming-Ru Su;V. Battaglia
采用高温热处理和不同ZnAl_2O_4包覆量（0.5，1，2.5wt%）制备了层状固溶体材料Li_（1.2）Ni_（0.2）Mn_（0.6）O_2。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）对材料进行了表征。从充放电循环、倍率性能和电化学阻抗谱（EIS）等方面评价了ZnAl2O4涂层对材料电化学性能的影响。TEM和选区电子衍射（SAED）结果表明，ZnAl2O4涂层在Li1.2Ni0.2Mn0.6O2上呈尖晶石结构。ZnAl2O4的加入提高了Li1.2Ni0.2Mn0.6O2材料的首次循环放电容量和库仑效率。用1wt%ZnAl2O4包覆的Li1.2Ni0.2Mn0.6O2显示出最高的放电容量（254.3 mAhg−1）、最高的容量保持率（50次循环98.6%）和最佳的倍率性能（10 C时84 mAhg− 1）。电化学阻抗谱表明，ZnAl2O4的加入降低了Li1.2Ni0.2Mn0.6O2电极的电阻，并使其具有良好的倍率性能。
Layered solid solution materials Li1.2Ni0.2Mn0.6O2were synthesized with one sample heat treated and three other coated with ZnAl2O4with varying amounts (0.5, 1 and 2.5 wt%) at high temperature. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effect of ZnAl2O4coatings on the electrochemical performance of the pristine material was evaluated from charge/discharge cycles, rate performance, and electrochemical impedance spectroscopy (EIS). The results from TEM and selected area electron diffraction (SAED) indicate that the ZnAl2O4coating assumes a spinel structure on the Li1.2Ni0.2Mn0.6O2. The discharge capacities and coulombic efficiencies of the Li1.2Ni0.2Mn0.6O2materials in the first cycle are improved with the addition of ZnAl2O4. Li1.2Ni0.2Mn0.6O2coated with 1 wt% ZnAl2O4shows the highest discharge capacity (254.3 mAhg−1), highest capacity retention (98.6% for 50 cycles), and best rate capability (84 mAhg−1at 10 C). EIS indicates that the resistance of Li1.2Ni0.2Mn0.6O2electrodes decrease with the addition of ZnAl2O4consistent with the excellent rate capability.