Synthesis of Li-excess layered cathode material with enhanced reversible capacity for Lithium ion batteries through the optimization of precursor synthesis method
Synthesis of Li-excess layered cathode material with enhanced reversible capacity for Lithium ion batteries through the optimization of precursor synthesis method
复制标题
DOI：
10.1016/j.electacta.2014.08.006
复制
发表时间：
2014-10
影响因子：
6.6
通讯作者：
Wenwen Zhao;Shinji Yamamoto;A. Tanaka;H. Noguchi
中科院分区：
文献类型：
--
作者：
Wenwen Zhao;Shinji Yamamoto;A. Tanaka;H. Noguchi
以固相(SS)、喷雾干燥(SD)和共沉淀法(CP)制备的P3-Na2/3Ni1/3Mn2/3O2为前驱体，通过还原-离子交换法制备了LixNi1/3Mn2/3O2正极材料。研究了前驱体合成方法对LixNi1/3Mn2/3O2的结构、形貌和电化学性能的影响。对LixNi1/3Mn2/3O2的X射线衍射谱分析表明，所有样品的X射线衍射图与锂过量层状正极材料的X射线衍射图相似。扫描电子显微镜(SEM)图像和Brunauer-Emment-Teller(BET)结果表明，前驱体合成方法使纳米粒子的粒径、团聚和比表面积发生了很大的变化。恒流充放电结果表明，共沉淀法制备的Li1.41Ni0.32Mn0.66O2+δ正极首次放电容量高达270mAhg−1，首次循环效率高达98%。Li1.41Ni0.32Mn0.66O2+δ正极经30次循环后的放电容量超过250mAhg−1，在500mag−1(2℃倍率)电流密度下的放电容量约为210mAhg−1。研究还发现，Li1.41Ni0.32Mn0.66O2+δ正极在可逆容量和倍率性能方面优于Li2/3Ni1/3Mn2/3O2正极。
LixNi1/3Mn2/3O2cathode materials have been synthesized through a facile reduction-ion exchange of P3-Na2/3Ni1/3Mn2/3O2precursors prepared by solid state (SS), spray dry (SD) and co-precipitation (CP) methods. The influence of precursor synthesis method on the structure, morphology and electrochemical performances of LixNi1/3Mn2/3O2has been investigated. X-ray diffraction (XRD) results of LixNi1/3Mn2/3O2demonstrate that all the samples exhibit similar XRD patterns as those of Lithium-excess layered cathode materials. Scanning Electron Microscope (SEM) images and Brunauer-Emment-Teller (BET) results present that the particle size, particle aggregation and surface area changed greatly with the precursor synthesis method. Galvanostatic charge-discharge results show that Li1.41Ni0.32Mn0.66O2+δcathode prepared from co-precipitation precursor exhibited high first discharge capacity of ca. 270 mAhg−1with an initial cycle efficiency as high as 98%. The discharge capacity of Li1.41Ni0.32Mn0.66O2+δcathode after 30 cycles is over 250 mAhg−1and it can deliver a discharge capacity roughly 210 mAhg−1at a current density of 500 mAg−1(2 C rate). Also, it was found that Li1.41Ni0.32Mn0.66O2+δcathode shows enhanced electrochemical performance over the Li2/3Ni1/3Mn2/3O2cathode with respect to reversible capacity and rate capability.