Synthesis, structural and electrochemical properties of LiNi_0.79Co_0.1Mn_0.1Cr_0.01O₂ via fast co-precipitation

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• 作者：Ling-jun Li ; Xin-hai Li ; Zhi-xing Wang ; Hua-jun Guo ; Peng Yue ; Wei Chen ; Ling Wu
• 关键词：Lithium ion battery ; Cathode material ; Cr substitution ; Electrochemical behavior
• 刊名：Journal of Alloys and Compounds
• 出版年：2010
• 出版时间：24 September 2010
• 年：2010
• 卷：507
• 期：1
• 页码：172-177
• 全文大小：535 K

文摘

A novel layered material of LiNi_0.79Co_0.1Mn_0.1Cr_0.01O₂ is synthesized by fast co-precipitation method. Transmission electron microscope (TEM) and energy dispersive analysis of X-rays (EDAX) exhibit that Cr is successfully incorporating into LiNi_0.8Co_0.1Mn_0.1O₂. X-ray diffraction (XRD) and Rietveld refinement show that cation mixing is reduced by Cr substitution. Cyclic voltammerty (CV) indicates that the Cr substitution could decrease Jahn–Teller distortion, and improve reversibility of Li⁺ ions during intercalating/deintercalating. Electrochemical impedance spectroscopy (EIS) reveals that Cr substitution has an effect on restraining the charge transfer impedance of cathode. Electrochemical studies confirm that Cr substitution for LiNi_0.8Co_0.1Mn_0.1O₂ also results in improved discharge capacity, initial coulombic efficiency, rate ability and cycling property of cathode. The capacity retention of LiNi_0.8Co_0.1Mn_0.1O₂ after 50 cycles at 5C is only 76.1 % , however, that of the LiNi_0.79Co_0.1Mn_0.1Cr_0.01O₂ is improved to 89.02 % . It is noted that the discharge capacity of LiNi_0.79Co_0.1Mn_0.1Cr_0.01O₂ is 209.9, 183, 171.4, 164.2 and 152.8 mAh g⁻¹ at 0.1, 1, 3, 5 and 10C, respectively, in the cut-off voltage of 2.7–4.3 V.