Improved cycling performance of 5 V spinel LiMn1.5Ni0.5O4 by amorphous FePO4 coating
Improved cycling performance of 5 V spinel LiMn1.5Ni0.5O4 by amorphous FePO4 coating
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非晶 FePO4 涂层改善 5 V 尖晶石 LiMn1.5Ni0.5O4 的循环性能
DOI：
10.1016/j.jpowsour.2012.07.058
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发表时间：
2012-12-01
影响因子：
9.2
通讯作者：
Zhang, Weifeng
中科院分区：
文献类型：
--
作者：
Liu, Dilong;Bai, Ying;Zhang, Weifeng
采用化学沉积法用FePO4对5V尖晶石LiMn1.5Ni0.5O4(LMnO)进行表面改性，以提高其循环稳定性。用X射线衍射仪、傅里叶变换红外光谱、透射电子显微镜和场发射扫描电子显微镜对原始的、0.5wt.%、1wt.%和3wt.%FePO4包覆的LMnO进行了表征。研究发现，包覆过程有利于无序-有序相变。对其循环性能的研究表明，1wt.%FePO4修饰的LMnO正极具有最好的循环性能，50次循环后的容量保持率为99.3%，远好于未修饰的LMnO的容量保持率(79%)。电化学阻抗谱被用来解释恒流结果。表面修饰样品循环性能的提高可以归因于电极与电解液之间接触面积的减小和不希望看到的厚SEI(固体电解质界面)层的抑制。(C)2012爱思唯尔B.V.保留所有权利。
Cycling stability of 5 V spinel LiMn1.5Ni0.5O4 (LMNO) is improved by surface modification with FePO4 through a chemical deposition method. The pristine, 0.5 wt.%, 1 wt.% and 3 wt.% FePO4-coated LMNO are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and field emission scanning electron microscopy. It is found that the coating process is in favor of the disorder-order phase transition. The investigation on their cycling performance demonstrates that 1 wt.% FePO4-modified LMNO cathode exhibits the best cycling performance, with the capacity retention ratio of 99.3% after 50 cycles, much better than that of the pristine LMNO (only 79%). Electrochemical impedance spectroscopy is applied to explain the galvanostatic results. The enhanced cycling performance of the surface-modified samples can be attributed to the decreasing contact area between the electrode and electrolyte and the suppression of undesirable thick SEI (solid electrolyte interfacial) layer. (C) 2012 Elsevier B.V. All rights reserved.