Sb₂O₃-modified LiNi_1/3Co_1/3Mn_1/3O₂ material with enhanced thermal safety and electrochemical property

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• 作者：Zenghui Han ; Jinpeng Yu ; Hui Zhan ; Xingjiang Liu ; Yunhong Zhou
• 关键词：Layered material ; Antimony oxide ; Lithium ion battery ; Electrochemical performance ; Thermal safety
• 刊名：Journal of Power Sources
• 出版年：15 May, 2014
• 年：2014
• 卷：254
• 期：Complete
• 页码：106-111
• 全文大小：1547 K

文摘

The layered LiMO₂ (M聽=聽Ni, Co and Mn) materials LiNi_1/3Co_1/3Mn_1/3O₂ and LiNi_0.4Co_0.2Mn_0.4O₂ are synthesized by rheological phase method. Sb₂O₃-modified phases are further obtained by mechanical ball milling treatment. The structure and morphology of the bare and modified samples are characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Charge/discharge tests indicate that the modified phases all improve cycling stability, rate capability and thermal safety. Careful comparison of the charge/discharge profiles reveals that the serious polarization increment in cycling is suppressed in the Sb₂O₃-modified LiMO₂ electrodes. AC impedance shows that Sb₂O₃/LiNi_1/3Co_1/3Mn_1/3O₂ electrode has smaller R_ct and R_f value. Further analysis proves that Sb₂O₃ hinders the reaction between electrolyte and cathode during charge/discharge process and helps to stabilize the SEI. Other experiments prove that using Sb₂O₃-coated separator can achieve similar positive effect on layered LiMO₂ cathode.