LiOH-LiNO3低共熔混合锂盐体系合成LiNi1/3Co1/3Mn1/3O2

Synthesis of LiNi_(1/3)Co_(1/3)Mn1/3O_2 Cathode Material by Eutectic Molten Salt LiOH-LiNO_3

利用低共熔组成的0.38LiOH·H2O-0.62LiNO3混合锂盐体系,与钴、镍、锰的氢氧化物在低温下自混合,无需前期研磨和后续洗涤,直接制备出锂离子正极材料LiNi1/3Co1/3Mn1/3O2.X射线衍射分析结果表明,合成的LiNi1/3Co1/3Mn1/3O2结晶度高,具有规整的层状α-NaFeO2结构,扫描电镜显示产物颗粒均匀,振实密度高达2.87g·cm-3.XPS分析结果表明,合成的样品中Ni、Co、Mn的价态分别是2+、3+、4+.充放电测试表明,材料具有良好的电化学性能,首次放电比容量为160mAh·g-1,循环50次后,材料的电化学性能没有明显的衰减.

The powder of LiNi1/3Co1/3Mn1/3O2 were prepared directly without artificial grinding and washing by a eutectic molten-salt mixture （0.38LiOH· H2O-0.62LiNO3） method. According to this method, the eutectic molten-salt mixture was self-mixed with precursor thoroughly at low temperature, and then sintered at a certain temperature. The tap-density of the powder obtained was 2.87 g·cm^-3. The well-layered α-NaFeO2 structure and regular morphology were confirmed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. XPS studies showed that the predominant oxidation states of Ni, Co, and Mn in the compound were 2＋, 3＋, and 4＋, respectively. Cathodic behaviour was examined by charge-discharge cycling. The synthesized powder showed a reversible capacity of 160 mAh ·g ^-1 at a specific current of 0.2C in the rang 3.0-4.3 V up to 50 cycles without noticeable capacity-fading.