Institute of Physical Chemistry, Leopold-Franzens-University Innsbruck , Innrain 52c, Innsbruck 6020, Austria.
Advanced Light Source (ALS) and Joint Center for Energy Storage Research (JCESR), Lawrence Berkeley National Laboratory , 1 Cyclotron Rd., Berkeley, California 94720, United States.
ACS Appl Mater Interfaces. 2017 Oct 25;9(42):36828-36836. doi: 10.1021/acsami.7b11388. Epub 2017 Oct 10.
Self-organized TiO nanotubes (NTs) with a preferential orientation along the [001] direction are anodically grown by controlling the water content in the fluoride-containing electrolyte. The intrinsic kinetic and thermodynamic properties of the Li intercalation process in the preferentially oriented (PO) TiO NTs and in a randomly oriented (RO) TiO NT reference are determined by combining complementary electrochemical methods, including electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic cycling. PO TiO NTs demonstrate an enhanced performance as anode material in Li-ion batteries due to faster interfacial Li insertion/extraction kinetics. It is shown that the thermodynamic properties, which describe the ability of the host material to intercalate Li ions, have a negligible influence on the superior performance of PO NTs. This work presents a straightforward approach for gaining important insight into the influence of the crystallographic orientation on lithiation/delithiation characteristics of nanostructured TiO based anode materials for Li-ion batteries. The introduced methodology has high potential for the evaluation of battery materials in terms of their lithiation/delithiation thermodynamics and kinetics in general.
通过控制含氟电解质中的含水量，沿[001]方向择优取向的自组织 TiO 纳米管（NTs）被阳极生长。通过结合互补的电化学方法，包括电化学阻抗谱（EIS）、循环伏安法（CV）和恒电流循环，确定了优先取向（PO）TiO NTs 和随机取向（RO）TiO NT 参考中 Li 嵌入过程的内在动力学和热力学性质。PO TiO NTs 由于具有更快的界面 Li 插入/提取动力学，因此作为锂离子电池的阳极材料表现出增强的性能。结果表明，描述主体材料嵌入 Li 离子能力的热力学性质对 PO NTs 的优异性能几乎没有影响。这项工作提供了一种直接的方法，可以深入了解晶体取向对锂离子电池用基于 TiO 的纳米结构阳极材料的锂化/脱锂特性的影响。所提出的方法具有评估电池材料的锂化/脱锂热力学和动力学的巨大潜力。
