Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5182, Université Lyon 1, Laboratoire de Chimie, 46 allée d'Italie, F69364 Lyon, France.
Faculty of Materials Science and Ceramics, Department of Chemistry of Silicates and Macromolecules, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland.
Nat Commun. 2017 May 26;8:15636. doi: 10.1038/ncomms15636.
High-performance Li-ion batteries require materials with well-designed and controlled structures on nanometre and micrometre scales. Electrochemical properties can be enhanced by reducing crystallite size and by manipulating structure and morphology. Here we show a method for preparing hierarchically structured LiTiO yielding nano- and microstructure well-suited for use in lithium-ion batteries. Scalable glycothermal synthesis yields well-crystallized primary 4-8 nm nanoparticles, assembled into porous secondary particles. X-ray photoelectron spectroscopy reveals presence of Ti only; combined with chemical analysis showing lithium deficiency, this suggests oxygen non-stoichiometry. Electron microscopy confirms hierarchical morphology of the obtained material. Extended cycling tests in half cells demonstrates capacity of 170 mAh g and no sign of capacity fading after 1,000 cycles at 50C rate (charging completed in 72 s). The particular combination of nanostructure, microstructure and non-stoichiometry for the prepared lithium titanate is believed to underlie the observed electrochemical performance of material.
高性能锂离子电池需要具有纳米和微米尺度上设计良好且受控结构的材料。通过减小晶粒尺寸和操纵结构和形态，可以提高电化学性能。在这里，我们展示了一种制备具有纳米和微结构的分级结构 LiTiO 的方法，这种结构非常适合用于锂离子电池。可扩展的糖热合成可得到结晶良好的 4-8nm 初级纳米颗粒，这些颗粒组装成多孔的二级颗粒。X 射线光电子能谱显示仅存在 Ti；结合表明锂不足的化学分析，这表明氧非化学计量。电子显微镜证实了所获得材料的分层形貌。在半电池中的扩展循环测试表明，在 50C 速率下循环 1000 次后，容量为 170mAhg，没有容量衰减的迹象（在 72 秒内完成充电）。所制备的钛酸锂的纳米结构、微观结构和非化学计量比的特殊组合被认为是该材料电化学性能的基础。
