Effect of MgO and TiO2 Coating on the Electrochemical Performance of Li-Rich Cathode Materials for Lithium-Ion Batteries
Effect of MgO and TiO2 Coating on the Electrochemical Performance of Li-Rich Cathode Materials for Lithium-Ion Batteries
复制标题
MgO和TiO2涂层对锂离子电池富锂正极材料电化学性能的影响
DOI：
10.1002/ente.201800829
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发表时间：
2019
影响因子：
3.8
通讯作者：
Zheng Jun-chao
中科院分区：
文献类型：
--
作者：
Xiao Bin;Wang Peng-bo;He Zhen-jiang;Yang Zhuo;Tang Lin-bo;An Chang-sheng;Zheng Jun-chao
采用简便的方法合成了具有纳米MgO和纳米tio2镀层的0.5Li2MnO3·0.5 lini0.5 mn0.3 co0.2 o2正极材料。这些厚度约为20 nm的纳米涂层均匀地涂覆在材料表面。通过纳米MgO和纳米tio2涂层，改性材料具有优异的电化学性能。在2.0-4.8 V电压范围内，纳米- MgO涂层和纳米- TiO2涂层的富锂材料在1C速率下循环100次后分别表现出147.56和137.96 mAh g - 1，在2C速率下分别表现出156.13和130.69 mAh g - 1。具有纳米MgO和纳米tio2涂层的材料在50次循环后具有90%以上的放电电压保持率，Li+迁移阻抗低，锂离子的扩散系数高。纳米MgO和纳米tio2涂层有助于降低材料表面li2co3的含量，抑制副反应。因此，这些材料在增强富锂阴极材料的电化学性能方面起着重要的作用。
0.5Li2MnO3·0.5LiNi0.5Mn0.3Co0.2O2cathode materials with nano‐MgO and nano‐TiO2coating layers are synthesized via a facile approach. These nanocoating layers with a thickness of ≈20 nm are homogeneously coated on the surface of the materials. With the nano‐MgO and nano‐TiO2coating layers, the modified materials deliver excellent electrochemical performance. Nano‐MgO‐coated and nano‐TiO2‐coated Li‐rich materials exhibit 147.56 and 137.96 mAh g−1after 100 cycles at 1C rate and deliver 156.13 and 130.69 mAh g−1at 2C rate, respectively, in the voltage range of 2.0–4.8 V. The materials with nano‐MgO and nano‐TiO2coating layers also show a high discharge voltage retention of more than 90% after 50 cycles, low impedance for Li+migration, and high diffusion coefficients of the lithium ions. Nano‐MgO and nano‐TiO2coating layers help decrease the content of Li2CO3on the surface of the materials and suppress side reactions. Thus, these materials play a significant role in strengthening the electrochemical performance of Li‐rich cathode materials.