Synthesis and charge-discharge properties of LiF-NiO composite as a cathode material for Li-ion batteries
Synthesis and charge-discharge properties of LiF-NiO composite as a cathode material for Li-ion batteries
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锂离子电池正极材料LiF-NiO复合材料的合成及充放电性能
DOI：
10.1016/j.jpowsour.2016.08.095
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发表时间：
2016
影响因子：
9.2
通讯作者：
Kenkichiro Kobayashi
中科院分区：
文献类型：
--
作者：
Yasumasa Tomita;Hiromasa Nasu;Yusuke Izumi;Juichi Arai;Satoshi Otsuka,Yohei Yamane;Koji Yamada;Yoshiumi Kohno;Kenkichiro Kobayashi
通过将等量的 LiF 和 NiO 机械研磨 12-144 小时，合成摩尔比为 1:1 的 LiF-NiO 复合材料。通过 XRD、充放电测量和 XPS 对合成的复合材料进行了研究。 NiO 的 XRD 峰随着球磨时间的增加而变宽，而 LiF 的 XRD 峰消失。 Rietveld分析表明，球磨72 h以上制备的LiF-NiO复合材料形成固溶体，其中Li+和Ni2+离子的排列是无序的。单独研磨的 LiF 和 NiO 样品没有表现出明显的放电容量，而复合材料则表现出很大的放电容量。此外，LiF-NiO 复合材料的放电容量随着研磨时间的增加而增加，研磨 144 h 制备的复合材料的放电容量为 216 mA h g−1，在 0.05 C 电压为 2.0-5.0 V 时平均电压为 3.53 V。XPS 数据表明，Ni 离子可能在充放电过程中反复氧化和还原，并且在充电至 5.0 V 期间，Ni2+ 离子部分氧化为 Ni3+ 离子。
LiF-NiO composites in a molar ratio of 1:1 are synthesized by the mechanical milling of equal amounts of LiF and NiO for 12–144 h. The synthesized composites are investigated by XRD, charge-discharge measurements, and XPS. The XRD peaks of NiO broaden with an increase in the milling time, while those of LiF disappear. Rietveld analysis shows that the LiF-NiO composites prepared by milling for more than 72 h form a solid solution and that the arrangement of Li+and Ni2+ions in them is disordered. The LiF and NiO samples milled individually do not exhibit a noticeable discharge capacity, while the composites show a large one. Further, the discharge capacity of the LiF-NiO composites increases with the milling time, with the composite prepared by milling for 144 h exhibiting a discharge capacity of 216 mA h g−1and an average voltage of 3.53 V at 0.05 C for voltages of 2.0–5.0 V. The XPS data suggest that the Ni ions are probably oxidized and reduced repeatedly during the charge-discharge process and that the Ni2+ions are partially oxidized to Ni3+ions during charging to 5.0 V.