Lithium-rich layered oxide nanowires bearing porous structures and spinel domains as cathode materials for lithium-ion batteries
Lithium-rich layered oxide nanowires bearing porous structures and spinel domains as cathode materials for lithium-ion batteries
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DOI：
10.1016/j.jpowsour.2019.02.036
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发表时间：
2019-04-01
影响因子：
9.2
通讯作者：
Peng, Dong-Liang
中科院分区：
文献类型：
--
作者：
Deng, Boda;Chen, Yuanzhi;Peng, Dong-Liang
富锂层状氧化物材料被认为是最有前途的高能锂离子电池正极材料之一。然而，由于其初始库仑效率较低、倍率能力和循环稳定性较差，目前其实际应用受到限制。在本研究中，我们采用共沉淀法制备了具有不同尖晶石相含量的Li1.2Mn0.54Ni0.13Co0.13O2纳米线。结构表征表明，所制备的纳米线是由相互连接的具有多孔结构的纳米亚基组成，尖晶石相嵌入在层状结构中。电化学测试表明，含有适量尖晶石相的Li1.2Mn0.54Ni0.13Co0.13O2纳米线在0.1C下具有291mAHg(-1)的高容量，在1C循环200次后容量保持率高达91.8%。研究结果还表明，尖晶石相含量对Li1.2Mn0.54Ni0.13Co0.13O2纳米线的电化学性能有影响。Li1.2Mn0.54Ni0.13Co0.13O2纳米线的一维多孔结构和尖晶石结构域的结合改善了电解液的接触和Li+的扩散，抑制了结构的退化。
Lithium-rich layered oxide materials are considered as one of the most promising cathodes for high-energy lithium-ion batteries. However, their practical applications are currently restricted by its low initial Coulombic efficiency and poor rate capability and cycling stability. In this study, we report the preparation of Li1.2Mn0.54Ni0.13Co0.13O2 nanowires that have porous structures with different contents of spinel phase via a co-precipitation method followed by carefully controlled calcination steps. Structural characterizations verify that the as-prepared nanowires are composed of interconnected nano-sized subunits with porous structures, and spinel phases are embedded inside the layered structure. The electrochemical measurements show that the Li1.2Mn0.54Ni0.13Co0.13O2 nanowires bearing moderate content of spinel phase exhibit a high capacity of 291 mAh g(-1) at 0.1 C and excellent capacity retention of 91.8% after 200 cycles at 1 C. The results also demonstrate that electrochemical performance of the Li1.2Mn0.54Ni0.13Co0.13O2 nanowires is influenced by the content of spinel phase which can be readily tuned by changing the heating rate in the calcination step. The combination of one-dimension porous structures and built-in spinel domains in Li1.2Mn0.54Ni0.13Co0.13O2 nanowires improves the electrolyte contact and Li+ diffusion, and restrains structural degeneration.