Preparation and electrochemical properties of Ca-doped Li4Ti5O12 as anode materials in lithium-ion battery
Preparation and electrochemical properties of Ca-doped Li4Ti5O12 as anode materials in lithium-ion battery
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DOI：
10.1016/j.electacta.2013.03.006
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发表时间：
2013-05
影响因子：
6.6
通讯作者：
Qianyu Zhang;Chengli Zhang;Bo Li;Shifei Kang;Xi Li;Yangang Wang
中科院分区：
文献类型：
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作者：
Qianyu Zhang;Chengli Zhang;Bo Li;Shifei Kang;Xi Li;Yangang Wang
在空气气氛中通过简单的固态反应合成了具有式Li 4 − xCaxTi 5 O 12（x=0，0.05，0.1，0.15，0.2）的Ca掺杂的钛酸锂作为阳极材料。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和循环伏安（CV）等测试手段对粉体的物相结构、形貌和电化学性能进行了表征。XRD分析表明，Ca的掺杂没有改变Li 4 − xCaxTi 5 O 12（0≤x≤0.2）的相结构，得到了无杂质的高结晶度Li 4 − xCaxTi 5 O 12粉体。SEM照片显示，所有样品具有相似的颗粒形貌，粒径分布在1-2μm之间。结果表明，钙掺杂钛酸锂作为锂离子电池负极材料具有优异的电化学性能，其中Li 3. 9 Ca 0. 1 Ti 5 O 12具有更高的比容量、更好的循环性能和倍率性能。Li3.9Ca0.1Ti5O12材料在1C、5C和10 C充放电倍率下100次循环后的放电容量分别为162.4mAhg−1、148.8mAhg− 1和138.7mAhg− 1。电化学阻抗谱（EIS）结果表明，Li 3. 9 Ca 0. 1 Ti 5 O 12电极具有最高的电子电导率和最快的锂离子扩散速率，表明该材料有望作为锂离子电池的高倍率负极材料。
Ca-doped lithium titanates with the formula of Li4−xCaxTi5O12(x=0, 0.05, 0.1, 0.15, 0.2) were synthesized as anode materials by a simple solid-state reaction in an air atmosphere. The phase structure, morphologies and electrochemical properties of the prepared powders were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. XRD revealed that the Ca-doping caused no change on the phase structure and highly crystalline Li4−xCaxTi5O12(0≤x≤0.2) powders without any impurity were obtained. SEM images showed that all samples had similar particulate morphologies and the particle size distribution was in the range of 1–2μm. It was observed that Ca-doped lithium titanates employed as the anode materials of lithium-ion batteries delivered excellent electrochemical performances, and sample Li3.9Ca0.1Ti5O12exhibited a higher specific capacity, better cycling performance and rate capability than other samples. The Li3.9Ca0.1Ti5O12material showed discharge capacities of 162.4mAhg−1, 148.8mAhg−1and 138.7mAhg−1after 100 cycles at 1C, 5C and 10C charge–discharge rates, respectively. Electrochemical impedance spectroscopy (EIS) revealed that the Li3.9Ca0.1Ti5O12electrode exhibited the highest electronic conductivity and fastest lithium-ion diffusivity, which indicated that this novel Li3.9Ca0.1Ti5O12material was promising as a high-rate anode material for the lithium-ion batteries.