采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结...采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).展开更多
采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电...采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、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晶体结构、微观形貌和电化学性能进行了系统研究。结果表明,x=0.2的材料具有最佳的高倍率性能和长循环稳定性。在2.7~4.5 V,1C下循环100次后(1 C=180 m A?g^(-1)),放电比容量为144 m Ah?g-1,容量保持率为92%;在10 C时的放电比容量仍能达到126 m Ah?g^(-1),相比于原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料的放电比容量(73 m Ah?g^(-1))有较大提高。此外,该材料的储能能力也非常突出,在0.1和10 C时的比能量密度分别为733.44和437.21 W×h?kg^(-1)。展开更多
The layered Li[Ni1/3Mn1/3Co1/3]O2 was separately synthesized by pretreatment process of ball mill method and solution phase route, using [Ni1/3Co1/3Mn1/3]3O4 and lithium hydroxide as raw materials. The physical and el...The layered Li[Ni1/3Mn1/3Co1/3]O2 was separately synthesized by pretreatment process of ball mill method and solution phase route, using [Ni1/3Co1/3Mn1/3]3O4 and lithium hydroxide as raw materials. The physical and electrochemical behaviors of Li[Ni1/3Mn1/3Co1/3]O2 were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, field emission scanning electron microscopy （FESEM） and electrochemical charge/discharge cycling tests. The results show that the difference in pretreatment process results in the difference in compound Li[Ni1/3Co1/3Mn1/3]O2 structure, morphology and the electrochemical characteristics. The Li[Ni1/3Mn1/3Co1/3]O2 prepared by solution phase route maintains the uniform spherical morphology of the [Ni1/3Co1/3Mn1/3]3O4, and it exhibits a higher capacity retention and better rate capability than that prepared by ball mill method. The initial discharge capacity of this sample reaches 178 mA-h/g and the capacity retention after 50 cycles is 98.7% at a current density of 20 mA/g. Moreover, it delivers high discharge capacity of 135 mA-h/g at a current density of 1 000 mA/g.展开更多
文摘采用改进的碳酸盐共沉淀与高温固相法相结合的方法制备出了高倍率性能的锂离子电池正极材料Li[Ni1/3Co1/3Mn1/3]O2,通过X射线衍射(XRD)、扫描电镜(SEM)、循环伏安扫描(CV)、电化学阻抗谱(EIS)和电化学性能测试等手段对材料进行表征.结果表明,该方法制备的材料具有良好的α-Na Fe O2型层状结构(R3m(166)),一次粒径平均大小为157 nm,二次颗粒成球形.同传统碳酸盐制备得到的材料相比,该材料具备良好的倍率性能和循环性能,在2.7-4.3 V电压范围内,0.1C(1.0C=180 m A?g-1)倍率下,首次放电比容量为156.4m Ah?g-1,库仑效率为81.9%.在较高倍率下,即0.5C、5.0C和20C时,其放电比容量分别为136.9、111.3、81.3m Ah?g-1.在1C倍率下100次循环容量保持率为92.9%,高于传统共沉淀法得到的材料(87.0%).
文摘采用草酸盐共沉淀法制备了一系列(x=0.1、0.2、0.3、0.4、0.5)异质结构的尖晶石/层状复合正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2。借助X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、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晶体结构、微观形貌和电化学性能进行了系统研究。结果表明,x=0.2的材料具有最佳的高倍率性能和长循环稳定性。在2.7~4.5 V,1C下循环100次后(1 C=180 m A?g^(-1)),放电比容量为144 m Ah?g-1,容量保持率为92%;在10 C时的放电比容量仍能达到126 m Ah?g^(-1),相比于原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料的放电比容量(73 m Ah?g^(-1))有较大提高。此外,该材料的储能能力也非常突出,在0.1和10 C时的比能量密度分别为733.44和437.21 W×h?kg^(-1)。
基金Project(20871101)supported by the National Natural Science Foundation of ChinaProject(2009WK2007)supported by Key Project of Science and Technology Department of Hunan Province,ChinaProject(CX2009B133)supported by Colleges and Universities in Hunan Province Plans to Graduate Research and Innovation,China
文摘The layered Li[Ni1/3Mn1/3Co1/3]O2 was separately synthesized by pretreatment process of ball mill method and solution phase route, using [Ni1/3Co1/3Mn1/3]3O4 and lithium hydroxide as raw materials. The physical and electrochemical behaviors of Li[Ni1/3Mn1/3Co1/3]O2 were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, field emission scanning electron microscopy （FESEM） and electrochemical charge/discharge cycling tests. The results show that the difference in pretreatment process results in the difference in compound Li[Ni1/3Co1/3Mn1/3]O2 structure, morphology and the electrochemical characteristics. The Li[Ni1/3Mn1/3Co1/3]O2 prepared by solution phase route maintains the uniform spherical morphology of the [Ni1/3Co1/3Mn1/3]3O4, and it exhibits a higher capacity retention and better rate capability than that prepared by ball mill method. The initial discharge capacity of this sample reaches 178 mA-h/g and the capacity retention after 50 cycles is 98.7% at a current density of 20 mA/g. Moreover, it delivers high discharge capacity of 135 mA-h/g at a current density of 1 000 mA/g.
