Improving the Cycling Performance of the Layered Ni-Rich Oxide Cathode by Introducing Low-Content Li₂MnO₃

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• 作者：Jun Yang ; Mengyan Hou ; Servane Haller ; Yonggang Wang ; Congxiao Wang ; Yongyao Xia ; ^{yyxia@fudan.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Layered structure ; Ni-rich oxide cathode ; Inactive component ; Cycling stability ; Lithium-ion batteries
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：20 January 2016
• 年：2016
• 卷：189
• 期：Complete
• 页码：101-110
• 全文大小：3964 K

文摘

The layered Ni-rich oxide LiNi_0.8Co_0.1Mn_0.1O₂ cathode has been significantly attractive due to its large reversible capacity (∼200 mAh g⁻¹). However, the inherent poor cycling stability of the Ni-based cathode materials is always a serious issue for restricting its commercialization. In this paper, we introduced Li₂MnO₃ as an electrochemical inactive component in Ni-rich oxide LiNi_0.8Co_0.1Mn_0.1O₂ to stabilize its structure. The modified LiNi_0.8Co_0.1Mn_0.1O₂ composites with low-content Li₂MnO₃ were prepared by a solid-state reaction process. The results from XRD structure refinement and SAED confirm that Li₂MnO₃ phase exists homogeneously in the composites. The modified LiNi_0.8Co_0.1Mn_0.1O₂ composites with inactive Li₂MnO₃ show much better cycling stability and stable average discharge voltage compared with the pristine one when charged to 4.5 V. Especially, the modified LiNi_0.8Co_0.1Mn_0.1O₂ composite with 10% Li₂MnO₃ (LNCMO-1090) delivers a reversible capacity of 207 mAh g⁻¹ and keeps 155 mAh g⁻¹ after 100 cycles at 20 mA g⁻¹ (0.1C), corresponding to a capacity retention of 75%, while LiNi_0.8Co_0.1Mn_0.1O₂ could only maintain a capacity of 128 mAh g⁻¹ with a capacity retention of 59% after 100 cycles. The improved cycling performance of the Li₂MnO₃-containing electrode could be attributed to the stabilized effect of Li₂MnO₃ on the electrode surface structure, as evidenced by the lower charge-transfer resistance.