Structural and mechanistic revelations on high capacity cation-disordered Li-rich oxides for rechargeable Li-ion batteries
Structural and mechanistic revelations on high capacity cation-disordered Li-rich oxides for rechargeable Li-ion batteries
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可充电锂离子电池用高容量阳离子无序富锂氧化物的结构和机理启示
DOI：
10.1016/j.ensm.2018.06.016
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发表时间：
2019-01
影响因子：
20.4
通讯作者：
Fangwei Wang
中科院分区：
文献类型：
--
作者：
Enyue Zhao;Lunhua He;Baotian Wang;Xiyang Li;Junrong Zhang;Yang Wu;Jie Chen;Shaoying Zhang;Tianjiao Liang;Yuanbo Chen;Xiqian Yu;Hong Li;Liquan Chen;Xuejie Huang;Hesheng Chen;Fangwei Wang
高容量的阳离子无序富锂氧化物不仅扩大了正极材料的化学设计空间，而且对高能量密度锂离子电池的发展起到了重要的推动作用。然而，仍然存在一些问题，如能力退化，阻碍了它们的实际应用。深入了解阳离子无序富锂氧化物的结构和机理，有利于进一步优化其性能。本文以新设计的高容量(~280 Ma h/g)无序Li1.2Ti0.35Ni0.35Nb0.1O1.8F0.2为模型化合物，结合第一性原理计算、同步X射线衍射仪、X射线对分布函数、X射线吸收光谱、原位X射线衍射仪和中子粉末衍射仪等手段，详细研究了其结构演变和循环过程中的电化学反应机理。实验证明，阳离子无序的富锂氧化物具有良好的结构稳定性和健壮的阴离子骨架。同时，还提出了高容量机理依赖于同时发生的阳离子和阴离子氧化还原反应，以及循环失氧引起的容量退化机理。在此基础上，进一步提出了阳离子无序富锂氧化物的优化策略和潜在应用。
High capacity cation-disordered Li-rich oxides not only enlarge the chemical design space of cathode materials, but also play an important role in promoting the development of high energy density Li-ion batteries. However, there are still some issues, such as capacity degradation, that impede their practical applications. In-depth understanding of the structure and mechanisms in cation-disordered Li-rich oxides is favorable for their further performance optimization. Herein, taking the new designed high capacity (~ 280 mA h/g) disordered Li1.2Ti0.35Ni0.35Nb0.1O1.8F0.2as a model compound, we meticulously study its structure evolution and electrochemical reaction mechanisms upon cycling by combination of first principles calculation, synchrony X-ray diffraction (SXRD), X-ray pair distribution function (XPDF), X-ray absorption spectroscopy (XAS), in situ XRD, and Neutron powder diffraction (NPD) et al. The excellent structure stability and robust anions framework of cation-disordered Li-rich oxides are experimentally demonstrated. Meanwhile, the high capacity mechanisms rely on the simultaneous cations and anions redox reactions and the capacity degradation mechanism induced by oxygen loss upon cycling are also proposed. Based on these revelations, the optimization strategy and potential applications of cation-disordered Li-rich oxides are further proposed.
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影响因子：
9.2
作者：
Mohanty, Debasish;Kalnaus, Sergiy;Daniel, Claus
通讯作者：
Daniel, Claus
影响因子：
16.6
作者：
Lee J;Papp JK;Clément RJ;Sallis S;Kwon DH;Shi T;Yang W;McCloskey BD;Ceder G
通讯作者：
Ceder G
影响因子：
--
作者：
Enyue Zhao;Lincan Fang;Minmin Chen;Dongfeng Chen;Qingzhen Huang;Zhong-bo Hu;Qing-Bo Yan;Meimei Wu-
通讯作者：
Enyue Zhao;Lincan Fang;Minmin Chen;Dongfeng Chen;Qingzhen Huang;Zhong-bo Hu;Qing-Bo Yan;Meimei Wu-
影响因子：
2.5
作者：
K. Nagayama;K. Kamioka;Eiichi Iwata;H. Oka;Y. Tokunaga;T. Okada
通讯作者：
K. Nagayama;K. Kamioka;Eiichi Iwata;H. Oka;Y. Tokunaga;T. Okada
影响因子：
8.6
作者：
Glazier, Stephen L.;Li, Jing;Dahn, J. R.
通讯作者：
Dahn, J. R.