Enhancing the durable performance of LiMn2O4 at high-rate and elevated temperature by nickel-magnesium dual doping

Yue Yu; Junming Guo; Mingwu Xiang; Changwei Su; Xiaofang Liu; Hongli Bai; Wei Bai; Kaijiao Duan

doi:10.1038/s41598-019-53494-7

Enhancing the durable performance of LiMn₂O₄ at high-rate and elevated temperature by nickel-magnesium dual doping

Sci Rep. 2019 Nov 14;9(1):16864. doi: 10.1038/s41598-019-53494-7.

Authors

Yue Yu^{1

2}, Junming Guo^{3

4}, Mingwu Xiang^{5

6}, Changwei Su^{1

2}, Xiaofang Liu^{1

2}, Hongli Bai^{1

2}, Wei Bai^{1

2}, Kaijiao Duan^{1

2}

Affiliations

¹ Key Laboratory of Green-chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming, 650500, China.
² National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, Yunnan Minzu University, Kunming, 650500, China.
³ Key Laboratory of Green-chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming, 650500, China. guojunming@tsinghua.org.cn.
⁴ National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, Yunnan Minzu University, Kunming, 650500, China. guojunming@tsinghua.org.cn.
⁵ Key Laboratory of Green-chemistry Materials in University of Yunnan Province, Yunnan Minzu University, Kunming, 650500, China. xmwbboy@163.com.
⁶ National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, Yunnan Minzu University, Kunming, 650500, China. xmwbboy@163.com.

Abstract

Various nickel and magnesium dual-doped LiNi_xMg_0.08Mn_1.92-xO₄ (x ≤ 0.15) were synthesized via a modified solid-state combustion method. All as-prepared samples show typical spinel phase with a well-defined polyhedron morphology. The Ni-Mg dual-doping obviously decreases the lattice parameter that gives rise to the lattice contraction. Owing to the synergistic merits of metal ions co-doping, the optimized LiNi_0.03Mg_0.08Mn_1.89O₄ delivers high initial capacity of 115.9 and 92.9 mAh·g^-1, whilst retains 77.1 and 69.7 mAh·g^-1 after 1000 cycles at 1 C and high current rate of 20 C, respectively. Even at 10 C and 55 °C, the LiNi_0.03Mg_0.08Mn_1.89O₄ also has a discharge capacity of 92.2 mAh·g^-1 and endures 500 cycles long-term life. Such excellent results are contributed to the fast Li⁺ diffusion and robust structure stability. The anatomical analysis of the 1000 long-cycled LiNi_0.03Mg_0.08Mn_1.89O₄ electrode further demonstrates the stable spinel structure via the mitigation of Jahn-Teller effect. Hence, the Ni-Mg co-doping can be a potential strategy to improve the high-rate capability and long cycle properties of cathode materials.

Abstract

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