Hydrothermal synthesis of nanostructured Co3O4 materials under pulsed magnetic field and with an aging technique, and their electrochemical performance as anode for lithium-ion battery
Hydrothermal synthesis of nanostructured Co3O4 materials under pulsed magnetic field and with an aging technique, and their electrochemical performance as anode for lithium-ion battery
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DOI：
10.1016/j.electacta.2009.08.068
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发表时间：
2009-12
影响因子：
6.6
通讯作者：
Mokhlesur M. Rahman;Jiazhao Wang;Xiaolong Deng;Ying Li;Huakun Liu
中科院分区：
文献类型：
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作者：
Mokhlesur M. Rahman;Jiazhao Wang;Xiaolong Deng;Ying Li;Huakun Liu
分别采用无磁场水热法（Co3O4-0T）、脉冲磁场法（Co3O4-4T）和时效法（Co3O4-Aging）制备了co3o4纳米颗粒样品作为锂离子电池正极材料。采用场发射扫描电镜（FE-SEM）和x射线衍射仪（XRD）研究了co3o4纳米颗粒的形貌和结构特性。FE-SEM测量表明，在4T磁场下形成的co3o4样品由许多准球形纳米颗粒组成的大球状组成，典型直径为~ 25nm，与无磁场制备的参比样品相比，具有更紧凑和光滑的表面。经过时效处理，形成了由众多球形纳米颗粒组成的大型co3o4空心球体，典型直径为~ 20nm。电化学测试结果表明，与其他样品相比，采用时效技术制备的co3o4材料的电化学性能最好。Co3O4-0T、Co3O4-4T和Co3O4-Aging材料的容量分别保持在274、348和407mAhg−1至100次循环，分别约为初始放电容量的26%、27%和30%。容量损失的大小为Co3O4-Aging<Co3O4-4T<Co3O4-0T。因此，形貌不仅影响锂离子电池的放电容量，而且影响锂离子电池的循环稳定性。
Co3O4nanoparticle samples were prepared as anode materials for lithium-ion batteries by the hydrothermal synthesis method without magnetic field (Co3O4-0T), under pulsed magnetic field (Co3O4-4T), and by using an aging technique (Co3O4-Aging), respectively. The morphology and structural properties of the Co3O4nanoparticles were investigated by field-emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). FE-SEM measurements demonstrated that the Co3O4sample formed under a 4T magnetic field consisted of large agglomerated spheres composed of numerous quasi-spherical nanoparticles with a typical diameter of ∼25nm and had more compact and smoother surfaces compared to a reference sample prepared without magnetic field. After the aging process, large Co3O4hollow spheres composed of numerous spherical nanoparticles with a typical diameter of ∼20nm were formed. Electrochemical measurements showed that Co3O4materials prepared by the aging technique (Co3O4-Aging) yielded the best electrochemical performance compared with the other samples. Capacities were maintained at 274, 348, and 407mAhg−1up to 100 cycles for the Co3O4-0T, Co3O4-4T, and Co3O4-Aging materials, which are about 26, 27, and 30% of initial discharge capacities, respectively. The capacity loss is in the order of Co3O4-Aging<Co3O4-4T<Co3O4-0T. Thus, the morphology affects not only the discharge capacity, but also the cycling stability of Li-ion batteries.