Tuning Li2MO3 phase abundance and suppressing migration of transition metal ions to improve the overall performance of Li- and Mn-rich layered oxide cathode
Tuning Li2MO3 phase abundance and suppressing migration of transition metal ions to improve the overall performance of Li- and Mn-rich layered oxide cathode
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调节Li2MO3相丰度并抑制过渡金属离子迁移以提高富锂和富锰层状氧化物正极的整体性能
DOI：
10.1016/j.jpowsour.2018.01.045
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发表时间：
2018
影响因子：
9.2
通讯作者：
Pan Hongge
中科院分区：
文献类型：
--
作者：
Zhang Shiming;Tang Tian;Ma Zhihua;Gu Haitao;Du Wubing;Gao Mingxia;Liu Yongfeng;Jian Dechao;Pan Hongge
用于锂离子电池（LIB）的富Li和富Mn层状氧化物阴极的差循环稳定性严重限制了它们的实际应用。不幸的是，目前改善其生命周期的策略牺牲了初始容量。在本文中，我们首次报道了通过用Mg 2+离子部分取代Li+离子来协同改善Li1.2Ni0.13Co0.13Mn0.54O2（LNCMO）正极材料的电化学性能，包括容量、循环稳定性和倍率性能的提高。通过恒电流充放电测试和电化学阻抗谱（EIS）评估电化学性能。用X射线衍射仪（XRD）和高分辨透射电子显微镜（HRTEM）对样品的结构和形貌进行了表征。与先前报道的用Mg 2+离子取代过渡金属（TM）离子相比，用Mg 2+离子取代Li+离子不仅显著改善了LNCMO阴极的容量保持率和倍率性能挑战，而且由于在循环期间抑制了TM离子的迁移，还显著抑制了它们的电压衰减。同时由于Li2MO3相的丰度增加，也增加了阴极的容量。
The poor cycling stability of Li- and Mn-rich layered oxide cathodes used in lithium-ion batteries (LIBs) has severely limited their practical application. Unfortunately, current strategies to improve their lifecycle sacrifice initial capacity. In this paper, we firstly report the synergistic improvement of the electrochemical performance of a Li1.2Ni0.13Co0.13Mn0.54O2(LNCMO) cathode material, including gains for capacity, cycling stability, and rate capability, by the partial substitution of Li+ions by Mg2+ions. Electrochemical performance is evaluated by a galvanostatic charge and discharge test and electrochemical impedance spectroscopy (EIS). Structure and morphology are characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). Compared with the substitution of transition metal (TM) ions with Mg2+ions reported previously, the substitution of Li+ions by Mg2+ions not only drastically ameliorates the capacity retention and rate performance challenges of LNCMO cathodes but also markedly suppresses their voltage fading, due to the inhibition of the migration of TM ions during cycling, while also increasing the capacity of the cathode due to an increased abundance of the Li2MO3phase.