Structure and lithium ion diffusion in lithium silicate glasses and at their interfaces with lithium lanthanum titanate crystals
Structure and lithium ion diffusion in lithium silicate glasses and at their interfaces with lithium lanthanum titanate crystals
复制标题
硅酸锂玻璃及其与钛酸锂镧晶体界面的结构和锂离子扩散
DOI：
10.1016/j.jnoncrysol.2012.05.015
复制
发表时间：
2012
影响因子：
3.5
通讯作者：
Chao‐hsu Chen
中科院分区：
文献类型：
--
作者：
Jincheng Du;Chao‐hsu Chen
固态锂离子电解质对于开发下一代更安全和高功率密度的锂离子电池具有重要意义。含锂玻璃如硅酸锂玻璃由于其高离子电导率而被广泛研究。最近，在多晶钛酸锂镧（LLT）陶瓷中引入硅酸锂玻璃作为晶粒之间的晶间薄膜，以在这些固态电解质中实现更高的锂离子电导率。在这项工作中，我们提出的结构和扩散行为的锂硅酸盐玻璃及其界面LLT晶体的分子动力学模拟的调查。利用分子动力学模拟方法对锂硅酸盐玻璃的短程和中程结构进行了表征，得到了陶瓷/玻璃界面模型。研究了锂离子在玻璃中和玻璃/陶瓷界面上的扩散行为，以及原子结构对扩散行为的影响。结果发现，在玻璃/晶体界面处存在少量的锂离子偏析。界面锂离子扩散能垒主要由玻璃相控制。
Solid state lithium ion electrolytes are important to the development of next generation safer and high power density lithium ion batteries. Lithium containing glasses such as lithium silicate glasses have been widely studied due to their high ionic conductivity. Recently, lithium silicate glasses were introduced in polycrystalline lithium lanthanum titanate (LLT) ceramics as intergranular thin films between the crystalline grains to achieve higher lithium ion conductivities in these solid state electrolytes. In this work, we present investigations of the structure and diffusion behavior of lithium silicate glasses and their interfaces with LLT crystals using molecular dynamics simulations. The short and medium range structures of the lithium silicate glasses were characterized and the ceramic/glass interface models were obtained using MD simulations. Lithium ion diffusion behaviors in the glass and across the glass/ceramic interfaces, as well as the effect of atomic structure on diffusion behaviors, were investigated. It was found that there existed a minor segregation of lithium ions at the glass/crystal interface. The interface lithium ion diffusion energy barrier was found to be dominated by the glass phase.