The Effect of Morphological Properties on the Electrochemical Behavior of High Tap Density C – LiFePO4 Prepared via Coprecipitation
The Effect of Morphological Properties on the Electrochemical Behavior of High Tap Density C – LiFePO4 Prepared via Coprecipitation
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DOI：
10.1149/1.2898684
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发表时间：
2008-06
影响因子：
3.9
通讯作者：
S. Oh;H. Bang;Seung‐Taek Myung;Y. Bae;Seong-Man Lee;Yang‐Kook Sun
中科院分区：
文献类型：
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作者：
S. Oh;H. Bang;Seung‐Taek Myung;Y. Bae;Seong-Man Lee;Yang‐Kook Sun
采用共沉淀法制备了锂离子二次电池正极材料高振实密度橄榄石型C-LiFePO 4。在650 - 850°C的不同煅烧温度下制备C-LiFePO 4粉末。通过X射线衍射、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和元素分析等手段对所制备的粉体的结构、电化学、形貌以及热稳定性进行了表征。得到了高结晶度的C-LiFePO 4，空间群为Pnma，振实密度为1.09gcm-3。元素分析表明，由于碳涂覆过程，最终产物含有约3重量%的碳。扫描电镜（SEM）显示，所制备的材料由粒径为1-2 μm的二次团聚体组成，而一次团聚体的粒径小于100 nm。在800°C下制备的C-LiFePO 4材料表现出优异的倍率性能，在0.1C放电倍率下为150.8mAh g-1，在10 C放电倍率下为106.7mAh g-1。
High-tap-density olivine C-LiFePO 4 , which is used as a positive electrode material in lithium-ion secondary batteries, was prepared via coprecipitation. The C-LiFePO 4 powders were prepared at various calcination temperatures between 650 and 850°C. The structural, electrochemical, and morphological properties, as well as the thermal stability of the prepared powders, were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy, and elemental analysis. Highly crystalline C-LiFePO 4 with a Pnma space group and a high tap density of 1.09 g cm -3 was obtained. Elemental analysis showed that the final product contained about 3 wt % carbon as a result of the carbon-coating process. SEM showed that the prepared materials consisted of secondary agglomerates with a 1-2 μm particle size, while the particle size of the primary particles was less than 100 nm. The C-LiFePΟ 4 materials prepared at 800°C exhibited an excellent rate capability of 150.8 mAh g -1 at the 0.1 C discharge rate and 106.7 mAh g -1 at the 10 C discharge rate.