Li-rich layered oxide coated by nanoscale MoOx film with oxygen vacancies and lower oxidation state as a high-performance cathode material
Li-rich layered oxide coated by nanoscale MoOx film with oxygen vacancies and lower oxidation state as a high-performance cathode material
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具有氧空位和较低氧化态的纳米MoOx薄膜包覆的富锂层状氧化物作为高性能正极材料
DOI：
10.1016/j.ceramint.2018.09.186
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发表时间：
2019
影响因子：
5.2
通讯作者：
Feiyu Kang
中科院分区：
文献类型：
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作者：
Zhe Yang;Jianjian Zhong;Jianling Li;Yanying Liu;Bangbang Niu;Feiyu Kang
富锂层状正极材料（Li1.2Ni0.13Co0.13Mn0.54O2）尽管具有超过250mAhg-1的超高比容量，但在第一次循环中会遭受严重的不可逆析氧、倍率性能不佳、容量衰减和电压衰减。在本文中，通过原位水解沉积在富锂材料（LLO）表面生长MoOx以改善这些问题。 LLO表面成功涂覆有非晶MoOx改性层，并在块体材料和熔覆层之间的夹层上诱导出尖晶石相，并通过XRD、SEM、XPS和TEM对其进行了表征。 3wt% MoOx修饰的Li1.2Ni0.13Co0.13Mn0.54O2表现出优异的电化学性能。该材料在0.5C（1C=250mAg-1）下循环100次后，容量保持率高达85.8%（容量为224.2mAhg-1），原始容量为187.4mAhg-1，容量保持率为75.1%，并且在5C下表现出192.0mAhg-1的高倍率性能。这些出色的电化学性能归因于材料中氧空位的存在。 MoOx可以在第一次活化过程中有效容纳Li2MnO3中的氧，并促进氧的可逆氧化还原过程。 MoOx涂层还可以消除材料表面的副反应并保持氧阵列的完整性。此外，MoOx中较低氧化态Mo的3d轨道延伸并部分重叠形成宽的t2g带，与具有快速Li+扩散通道的尖晶石相相结合，可以显着降低Li+扩散能垒并提高其倍率性能。
Li-rich layered cathode material (Li1.2Ni0.13Co0.13Mn0.54O2) is subjected to severe irreversible oxygen evolution for the first cycle, barren rate performance, capacity fading and voltage decay despite the ultrahigh specific capacity over 250 mAh g–1. In this paper, MoOxwas grown on the surface of lithium-rich material (LLO) via in situ hydrolysis deposition to ameliorate these problems. The surface of LLO was successfully coated with an amorphous MoOxmodification layer, and a spinel phase was induced on the interlayer between the bulk material and the cladding layer, which was characterized by XRD, SEM, XPS and TEM. The Li1.2Ni0.13Co0.13Mn0.54O2modified with 3 wt% MoOxexhibits the excellent electrochemical performance. The material performs higher capacity retention of 85.8% with 224.2 mAh g–1compared with the pristine one which retains 75.1% with 187.4 mAh g–1after 100 cycles at 0.5 C (1 C = 250 mA g–1) and exhibits high rate performance of 192.0 mAh g–1at 5 C. These outstanding electrochemical properties are attributed to the presence of oxygen vacancies in the MoOxthat can effectively accommodate the oxygen from the Li2MnO3during the first cycle of activation and promote oxygen reversible redox process. The MoOxcoating layer can also eliminate side reactions on the surface of the material and maintain the integrity of the oxygen array. Furthermore, the 3d orbitals of lower oxidation state Mo in MoOxextend and partially overlap to form wide t2gbands, combined with the spinel phase possessing fast Li+diffusion channels, which can significantly reduce the Li+diffusion energy barrier and improve its rate performance.
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DOI：
10.1002/celc.201800061
发表时间：
2018-06
期刊：
--
影响因子：
--
作者：
Shuaifeng Lou;M. Yulin;Zhenxing Zhou;Hua Huo;Pengjian Zuo;Xinqun Cheng;X. Qu;Yunzhi Gao;C. Du
通讯作者：
Shuaifeng Lou;M. Yulin;Zhenxing Zhou;Hua Huo;Pengjian Zuo;Xinqun Cheng;X. Qu;Yunzhi Gao;C. Du
影响因子：
41.2
作者：
Sathiya, M.;Abakumov, A. M.;Tarascon, J-M.
通讯作者：
Tarascon, J-M.
影响因子：
3.7
作者：
Koga, H.;Croguennec, L.;Belin, S.
通讯作者：
Belin, S.
影响因子：
--
作者：
Qingrui Xue;Jianling Li;Guofeng Xu;Hongwei Zhou;Xindong Wang;F. Kang
通讯作者：
Qingrui Xue;Jianling Li;Guofeng Xu;Hongwei Zhou;Xindong Wang;F. Kang
影响因子：
9.2
作者：
Ito, Atsushi;Li, Decheng;Sato, Yuichi
通讯作者：
Sato, Yuichi