Enhanced cycle stability of Na0.9Ni0.45Mn0.55O2 through tailoring O3/P2 hybrid structures for sodium-ion batteries
Enhanced cycle stability of Na0.9Ni0.45Mn0.55O2 through tailoring O3/P2 hybrid structures for sodium-ion batteries
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通过定制钠离子电池O3/P2混合结构增强Na0.9Ni0.45Mn0.55O2的循环稳定性
DOI：
10.1016/j.jpowsour.2018.10.058
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发表时间：
2018-12-01
影响因子：
9.2
通讯作者：
Zhong, Shengkui
中科院分区：
文献类型：
--
作者：
Chen, Jie;Li, Lingjun;Zhong, Shengkui
层状O3型二元镍锰氧化物在钠离子电池中的实际应用面临的一个关键挑战是延长循环过程中的结构稳定性较差。构建O3/P2杂化复合材料的方法可以部分提高循环稳定性，但由于过量的钠缺乏和锂的替代，一般的方法牺牲了O3型正极的高容量和低成本的优点。在这里，我们合理地设计了一系列新型的臭氧掺杂Na0.9-xNi0.45Mn0.55O2(x=0.02，0.04和0.08)阴极，在保持优异的长期稳定性的同时，显示出高容量。特别是，优化后的O_3/P_2Na0.88Ni0.45Mn0.55O2正极材料在1C(1C=150 mA·g~(-1))下循环250次，容量保持率为71.1%，比O_3-Na0.9Ni0.45Mn0.55O2正极材料的循环性能提高32%；首次放电容量为75.9 mA H.G(-1)，在10C循环1000次后容量保持率为72.4%。更重要的是，后循环分析表明，O_3/P_2杂化相成功地抑制了电池工作过程中Na0.9Ni0.45Mn0.55O2的结构退化。这项研究为设计高性能的钠离子电池正极材料提供了新的视角。
A critical challenge for the practical use of the layered O3-type binary nickel manganese oxides for sodium-ion batteries is the poor structural stability during extended cycling The approaches of constructing O3/P2 hybrid composites can partially improve the cycling stability, but general approaches sacrifice the advantages of high capacity and low cost of the O3-type cathodes due to excessive sodium deficiency and lithium substitution. Here, we rationally design a serial of novel O3-majority hybrid Na0.9-xNi0.45Mn0.55O2 (x = 0.02, 0.04 and 0.08) cathodes, which exhibit high capacities while maintaining exceptional long-term stability. Particularly, the optimized O3/P2 Na0.88Ni0.45Mn0.55O2 composite delivers 106.7 mA h.g(-1) with 71.1% capacity retention after 250 cycles at 1 C (1C = 150 mA g(-1)), the cyclability is 32% higher than that of the O3-Na0.9Ni0.45Mn0.55O2 cathode; and it also delivers a initial discharge capacity of 75.9 mA h.g(-1), maintaining 72.4% capacity retention after 1000 cycles at 10 C. More importantly, the post-cycling analyses demonstrate O3/P2 hybrid phases successfully suppress the structural degradation of Na0.9Ni0.45Mn0.55O2 during battery operation. This study provides new perspectives in designing high performance cathodes for sodium-ion batteries.