Role of Mn Content on the Electrochemical Properties of Nickel-Rich Layered LiNi0.8-xCo0.1Mn0.1+xO2 (0.0 ≤ x ≤ 0.08) Cathodes for Lithium-Ion Batteries
Role of Mn Content on the Electrochemical Properties of Nickel-Rich Layered LiNi0.8-xCo0.1Mn0.1+xO2 (0.0 ≤ x ≤ 0.08) Cathodes for Lithium-Ion Batteries
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DOI：
10.1021/acsami.5b00788
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发表时间：
2015-04-01
影响因子：
9.5
通讯作者：
Manthiram, Arumugam
中科院分区：
文献类型：
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作者：
Zheng, Jianming;Kan, Wang Hay;Manthiram, Arumugam
富镍层状氧化物（Ni含量>60%）由于其高放电容量、高能量密度和低成本而成为锂离子电池的有希望的阴极候选物。然而，容量衰减快，热稳定性差，对环境湿度敏感仍然困扰着它们的大规模应用。本文系统地研究了Mn含量对富Ni正极材料LiNi0.8-xCo0.1Mn0.1+ xO 2（0.0 = x = 0.08）的结构、形貌、电化学性能和热稳定性的影响。结果表明，随着Mn含量的增加和Ni含量的减少，LiNi（0.8-x）Co（0.1）Mn（0.1+）xO（2）的循环稳定性显著提高，截止充电电压为4.5V。高Mn含量的LiNi 0.72Co 0.10Mn 0.18O2在室温下以0.2C倍率循环100次后的容量保持率为85.7%，远高于低Mn含量的LiNi 0.80Co 0.10Mn 0.10O2（64.0%）和LiNi 0.76Co 0.10Mn 0.14O2（72.9%）。高Mn含量电极LiNi0.72Co0.10Mn0.18O2的改进的容量保持率是由于电极/电解质界面的稳定性，如由较低的固体电解质界面（SEI）电阻和电荷转移电阻所证明的。此外，随着Mn含量的增加和Ni含量的减少，富Ni阴极的热稳定性也显著提高。
Ni-rich layered oxides (Ni content >60%) are promising cathode candidates for Li-ion batteries because of their high discharge capacity, high energy density, and low cost. However, fast capacity fading, poor thermal stability, and sensitivity to the ambient moisture still plague their mass application. In this work, we systematically investigate the effects of Mn content on the structure, morphology, electrochemical performance, and thermal stability of the Ni-rich cathode materials LiNi0.8-xCo0.1Mn0.1+xO2 (0.0 = x = 0.08). It is demonstrated that with the increase in Mn content and decrease in Ni content, the cycling stability of LiNi(0.8-x)Co(0.1)Mn(0.1+)xO(2) to a cutoff charge voltage of 4.5 V is significantly improved. The high-Mn-content electrode LiNi0.72Co0.10Mn0.18O2 shows a capacity retention of 85.7% after 100 cycles at a 0.2 C rate at room temperature, much higher than those of the lower Mn-content samples LiNi0.80Co0.10Mn0.10O2 (64.0%) and LiNi0.76Co0.10Mn0.14O2 (72.9%). The improved capacity retention of the high-Mn-content electrode LiNi0.72Co0.10Mn0.18O2 is due to the stabilization of the electrode/electrolyte interface, as evidenced by the lower solid-electrolyte interphase (SEI) resistance and charge-transfer resistance. Furthermore, with the increase in Mn content and decrease in Ni content, the thermal stability of the Ni-rich cathode is also remarkably enhanced.