Enhanced electrochemical performance of Li-rich cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O-2 by surface modification with lithium ion conductor Li3PO4
Enhanced electrochemical performance of Li-rich cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O-2 by surface modification with lithium ion conductor Li3PO4
复制标题
通过锂离子导体Li3PO4表面修饰增强富锂正极Li[Li0.2Mn0.54Ni0.13Co0.13]O-2的电化学性能
DOI：
10.1016/j.apsusc.2016.02.139
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发表时间：
2016
影响因子：
6.7
通讯作者：
Qi Xiwei
中科院分区：
文献类型：
--
作者：
Wang Zhiyuan;Luo Shaohua;Ren Jie;Wang Dan;Qi Xiwei
采用共沉淀法和高温煅烧法制备了富锂层状正极材料Li[Li 0. 2 Mn 0. 54 Ni 0. 13 Co 0. 13] O2，并通过球磨和退火处理成功地用纳米Li 3 PO 4对其进行了改性。TEM和EDS分析表明，Li 3 PO 4均匀包覆在Li[Li0.2Mn0.54Ni0.13Co0.13]O2颗粒表面。包覆锂离子导体Li 3 PO 4可显著提高Li[Li0.2Mn0.54Ni0.13Co0.13] O2的电化学性能。Li 3 PO 4涂层样品在0.05 C下具有284.7 mAhg− 1的高初始放电容量，在0.5 C下100次循环后保持192.6 mAhg− 1，高于原始样品（0.05 C下244 mAhg− 1和0.5 C下100次循环后168.2 mAhg− 1）。电化学阻抗谱（EIS）表明，与Li/Li[Li0.2Mn0.54Ni0.13Co0.13]O2相比，Li/Li 3 PO 4包覆的Li[Li0.2Mn0.54Ni0.13Co0.13] O2电池的电阻降低，这表明Li 3 PO 4涂层具有高离子电导率，（6.6 × 10− 8 S cm−1）有利于锂离子通过电极和电解质之间的界面扩散，加速电荷转移过程。此外，Li 3 PO 4涂层还可以作为保护层，以保护阴极材料免受电解质的侵蚀。这两个方面解释了Li 3 PO 4包覆的Li[Li0.2Mn0.54Ni0.13Co0.13]O2的增强的电化学性能。
Li-rich layered cathode Li[Li0.2Mn0.54Ni0.13Co0.13]O2is prepared via a co-precipitation followed with high-temperature calcination, and then successfully modified with nano-Li3PO4by ball milling and annealing. The TEM and EDS reveal that Li3PO4is homogeneously coated on the particle surface of Li[Li0.2Mn0.54Ni0.13Co0.13]O2. And the electrochemical performance of Li[Li0.2Mn0.54Ni0.13Co0.13]O2is significantly improved by coating with lithium ion conductor Li3PO4. The Li3PO4-coated sample delivers a high initial discharge capacity of 284.7 mAhg−1at 0.05 C, and retains 192.6 mAhg−1after 100 cycles at 0.5 C, which is higher than that of the pristine sample (244 mAhg−1at 0.05 C and 168.2 mAhg−1after 100 cycles at 0.5 C). The electrochemical impedance spectroscopy (EIS) demonstrates that the resistance for Li/Li3PO4-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2cell was reduced compared to Li/Li[Li0.2Mn0.54Ni0.13Co0.13]O2, which indicates the Li3PO4coating layer with high ionic conductivity (6.6 × 10−8S cm−1) facilitates the diffusion of lithium ions through the interface between electrode and electrolyte and accelerates the charge transfer process. What is more, the Li3PO4coating layer can also act as a protection layer to protect the cathode material from encroachment of electrolyte. The two aspects account for the enhanced electrochemical performance of Li3PO4-coated Li[Li0.2Mn0.54Ni0.13Co0.13]O2.