Kuganathan Navaratnarajah, Ganeshalingam Sashikesh, Chroneos Alexander
Department of Materials, Imperial College London, London SW7 2AZ, UK.
Faculty of Engineering, Environment and Computing, Coventry University, Coventry CV1 5FB, UK.
Materials (Basel). 2019 Sep 4;12(18):2851. doi: 10.3390/ma12182851.
In this study, force field-based simulations are employed to examine the defects in Li-ion diffusion pathways together with activation energies and a solution of dopants in LiTiO. The lowest defect energy process is found to be the Li Frenkel (0.66 eV/defect), inferring that this defect process is most likely to occur. This study further identifies that cation exchange (Li-Ti) disorder is the second lowest defect energy process. Long-range diffusion of Li-ion is observed in the -plane with activation energy of 0.25 eV, inferring that Li ions move fast in this material. The most promising trivalent dopant at the Ti site is Co, which would create more Li interstitials in the lattice required for high capacity. The favorable isovalent dopant is the Ge at the Ti site, which may alter the mechanical property of this material. The electronic structures of the favorable dopants are analyzed using density functional theory (DFT) calculations.
在本研究中，基于力场的模拟被用于研究锂离子扩散路径中的缺陷以及激活能和锂钛氧化物中掺杂剂的溶液。发现最低缺陷能量过程是锂弗伦克尔缺陷（0.66电子伏特/缺陷），这表明该缺陷过程最有可能发生。本研究进一步确定阳离子交换（锂 - 钛）无序是第二低缺陷能量过程。在平面中观察到锂离子的长程扩散，激活能为0.25电子伏特，这表明锂离子在这种材料中移动速度很快。在钛位点最有前景的三价掺杂剂是钴，它会在晶格中产生更多高容量所需的锂间隙。有利的等价掺杂剂是钛位点的锗，它可能会改变这种材料的机械性能。使用密度泛函理论（DFT）计算分析了有利掺杂剂的电子结构。
