Effect of precursor and synthesis temperature on the structural and electrochemical properties of Li(Ni0.5Co0.2Mn0.3)O2
Effect of precursor and synthesis temperature on the structural and electrochemical properties of Li(Ni0.5Co0.2Mn0.3)O2
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DOI：
10.1016/j.electacta.2012.05.035
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发表时间：
2012-07
影响因子：
6.6
通讯作者：
Kuichen Wu;Fei Wang;Lulu Gao;Man-Rong Li;Lingli Xiao;Liutao Zhao;Sujuan Hu;Xiaojun Wang;Zhongling Xu;Qingguo Wu
中科院分区：
文献类型：
--
作者：
Kuichen Wu;Fei Wang;Lulu Gao;Man-Rong Li;Lingli Xiao;Liutao Zhao;Sujuan Hu;Xiaojun Wang;Zhongling Xu;Qingguo Wu
以Li2CO3和三种不同物理性质的过渡金属氢氧化物(Ni0.5Co0.2Mn0.3)(OH)2(NMC氢氧化物)为原料，采用固相反应法制备了Li(Ni0.5Co0.2Mn0.3)O2层状材料。通过X射线衍射仪、扫描电子显微镜和电化学测试等手段对合成的Li(Ni0.5Co0.2Mn0.3)O2产物进行了表征，得到了不同合成温度下的Li(Ni0.5Co0.2Mn0.3)O2的物性和电化学性质，得到了过渡金属氢氧化物前驱体的性质。反应温度越高，一次粒径(PPS)越大，粒度分布越宽。PPS较小的前驱体在相同条件下合成时PPS较大。其电化学性能与Li(Ni0.5Co0.2Mn0.3)O2的物理性质有关。结晶较好、阳离子有序的层状材料具有较高的初始容量，而较小且均匀的PPS导致较高的容量保持率。以PPS尺寸最小的(Ni0.5Co0.2Mn0.3)(OH)2为起始前驱体，在880℃、10h的气氛中合成的Li(Ni0.5Co0.2Mn0.3)O2具有最好的综合电化学性能，在半电池中1C倍率和敲击密度约2.7g/cm~3下循环50次后，容量保持率达96%，放电容量超过171mAhg/g。
Li(Ni0.5Co0.2Mn0.3)O2layered materials were synthesized by solid-state reaction using Li2CO3and three transition-metal hydroxide precursors of composition (Ni0.5Co0.2Mn0.3)(OH)2(NMC Hydroxide) with different physical properties. Characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical testing, etc., the final Li(Ni0.5Co0.2Mn0.3)O2products showed different physical and electrochemical properties depending on their synthesis temperatures and the properties of transition-metal hydroxide precursors were got. Higher reaction temperature results in bigger primary particle size (PPS) and broader size distribution. Precursor with smaller PPS results in larger PPS when synthesized at the same condition. The electrochemical performance is related to the physical properties of Li(Ni0.5Co0.2Mn0.3)O2. Better crystallized and cation ordered layered material has higher initial capacity while smaller and uniform PPS results in higher capacity retention rate. The Li(Ni0.5Co0.2Mn0.3)O2synthesized at 880°C for 10h in atmosphere using (Ni0.5Co0.2Mn0.3)(OH)2with smallest PPS size as the starting precursor showed the best overall electrochemical properties with a high discharge capacity over 171mAh/g with a capacity retention >96% after 50 cycles at 1C rate in a half battery and tap density about 2.7g/cm3.