Nanosecond quantum molecular dynamics simulations of the lithium superionic conductor Li4-xGe1-xPxS4

作者：Nishino Shinya^*; Fujiwara Takeo; Yamasaki Hisatsugu

来源：Physical Review B, 2014, 90(2): 024303.

DOI：10.1103/PhysRevB.90.024303

The microscopic origin of high conductivity at room temperatures in lithium superionic conductors has remained a fundamental unsolved problem, although the recent discovery of Li10GeP2S12 was a great step toward the application of solid electrolytes. We achieve long-time (2-ns) tight-binding molecular dynamics simulations of Li4-xGe1-xPxS4 and observe the diffusion process where lithium atoms collectively hop into neighboring lithium sites by kicking the lithium atoms occupying these sites out. Furthermore, it is found that excess lithium atoms or doped lithium vacancies trigger a new diffusion process and drastically reduce the activation energy. We discuss the dynamic properties of lithium atoms in these materials, such as the diffusion constant, the activation energy, and the diffusion path.

• 出版日期2014-7-18