文章基本信息

标题：High rate capability caused by surface cubic spinels in Li-rich layer-structured cathodes for Li-ion batteries
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作者：Bohang Song ; Hongwei Liu ; Zongwen Liu 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2013
卷号：3
DOI：10.1038/srep03094
出版社：Springer Nature
摘要：Modified Li-rich layered cathode Li(Li_0.2Mn_0.54Ni_0.13Co_0.13)O₂ has been synthesized by a simple strategy of using surface treatment with various amounts (0–30 wt.%) of Super P (carbon black). Based on detailed characterizations from X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS), it is suggested that the phase transformation from Li₂MnO₃-type of structure to spinel-like phase take place at the surface regions of particles during post annealing process at 350°C, leading to increase in both first coulombic efficiency and rate capability, from 78% and 100 mAh·g⁻¹ (charge capacity at 2500 mA·g⁻¹) of the pristine material to 93.4% and 200 mAh·g⁻¹. The evidences of spinel formation and the reasons for electrochemical enhancement are systematically investigated.