锂离子电池正极材料LiNi0.75-xCoxMn0.25O2的合成及电化学性能研究 |
Synthesis and Electrochemical Properties of LiNi0.75-xCoxMn0.25O2 as Cathode Materials for Li-ion Batteries |
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摘要: 以LiOH·H2O、Ni(OAc)2·4H2O、Co(OAc)2·4H2O和MnO2为原料,在水热反应釜中预处理,然后进行高温固相反应,合成了一系列锂镍钴锰氧化物LiNi0.75-xCoxMn0.25O2(x=0.05,0.10,0.15,0.20,0.25)。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学性能测试对所得样品的结构、形貌、粒径及电化学性能进行了表征。结果表明,当x=0.20时,所合成的正极材料具有很好的α-NaFeO2型层状晶体结构,晶胞参数a=0.286 1 nm,c=1.416 4 nm, V=0.100 4 nm3,以50 mA·g-1的电流密度在3~4.3 V(vs Li/Li+)充放电时,首次放电比容量达172.5 mAh·g-1,首次放电效率高达90.9%,30个循环后其放电比容量依然保持在161.1 mAh·g-1。 |
关键词: LiNi0.75-xCoxMn0.25O2 锂离子电池 正极材料 电化学性能 |
基金项目: |
Abstract: LiNi0.75-xCoxMn0.25O2(x=0.05, 0.10, 0.15, 0.20, 0.25) compounds were synthesized from LiOH·H2O, Ni(OAc)2·4H2O, Co(OAc)2·4H2O and MnO2. The starting materials were pre-treated in an autoclave and then calcined at 730 ℃ under flowing oxygen. The products were analyzed by X-ray diffraction spectroscopy(XRD), scanning electron microscopy (SEM) and electrochemical tests. XRD results showed that all samples were of layered α-NaFeO2 (space group R3m) structure. The initial discharge capacities were all more than 160 mAh·g-1 in the voltage range of 3~4.3 V (vs Li/Li+) and all samples had good cyclic performance. LiNi0.55Co0.20Mn0.25O2 exhibited the best electrochemical properties in the five compounds. It showed an initial discharge capacity of 172.5 mAh·g-1 and remained 161.1 mAh·g-1 after 30 cycles. |
Keywords: Lithium nickel cobalt manganese oxides Lithium-ion batteries cathode materials electrochemical properties |
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摘要点击次数: 1975 |
全文下载次数: 2037 |
袁超群,李道聪,沈玉芳,彭正合,周运鸿.锂离子电池正极材料LiNi0.75-xCoxMn0.25O2的合成及电化学性能研究[J].无机化学学报,2006,22(9):1645-1650. |
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