| 熔盐法合成电化学性能优异的富锂层状正极材料Li1.5Ni0.25Mn0.75O2.5 |
| Effective Enhancement of the Electrochemical Performance of Layered Li-Rich Cathode Li1.5Ni0.25Mn0.75O2.5 by a Facile Molten Salt Method for Lithium-Ion Batteries |
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| 摘要: 采用氢氧化物共沉淀和熔盐法相结合的方法制备得到了电化学性能优异的富锂锰基Li1.5Ni0.25Mn0.75O2.5正极材料。借助X射线衍射（XRD）分析、扫描电镜（SEM）、感应耦合等离子体原子发射光谱（ICP-AES）、X射线光电子能谱（XPS）、电化学阻抗谱（EIS）和恒电流充放电测试等表征手段对材料的颗粒形貌、晶体结构和电化学性能进行了系统研究。XRD结果表明该材料具有完善的α-NaFeO2层状结构（空间群为R3m）和较低的Li+/Ni2+阳离子混排。电化学性能测试表明该材料的首次不可逆容量损失较小，且倍率性能和循环稳定性能十分优异。具体而言，在2.0~4.8 V，0.1C时的首次不可逆容量损失为50 mAh·g-1（首次库伦效率84%）；在10C时的放电比容量还能达到102 mAh·g-1；在0.5C下循环100次后，放电比容量为205 mAh·g-1（容量保持率90%）。 |
| 关键词: 熔盐法 氢氧化物共沉淀法 富锂正极材料 电化学性能 锂离子电池 |
| 基金项目: 国家自然科学基金（No.21506133）和四川省科技支撑计划（No.2014GZ0077）资助项目 |
| Abstract: A Li-rich Mn-based Li1.5Ni0.25Mn0.75O2.5 cathode material with excellent electrochemical performance is prepared using a combination of hydroxide co-precipitation and molten salt method. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma-atomic emission spectrometer (ICP-AES), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge tests are employed to analyze the particle morphology, crystal structure, and electrochemical properties of the as-prepared material. XRD results indicate that this sample has a more ordered α-NaFeO2 structure (space group R3m), and reduced Li+/Ni2+ cation mixing. Electrochemical results confirm that this sample has a dramatically decreased initial irreversible capacity loss, and excellent rate performance and cycling stability. Specifically, it delivers a small initial irreversible capacity loss of 50 mAh·g-1 (the first coulombic efficiency is 84%) between 2.0 and 4.8 V at 0.1C. At 10C rate, it can still exhibit a high discharge capacity of 102 mAh·g-1. After 100 cycles at 0.5C, the cathode also shows a discharge capacity of 205 mAh·g-1 with capacity retention of 90%. |
| Keywords: molten salt method hydroxide co-precipitation method Li-rich cathode material electrochemical performance lithium-ion battery |
| 投稿时间：2016-11-28 修订日期：2017-04-13 |
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| 郑卓,杨秀山,滑纬博,唐艳.熔盐法合成电化学性能优异的富锂层状正极材料Li1.5Ni0.25Mn0.75O2.5[J].无机化学学报,2017,33(6):963-969. |
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