NASICON结构化合物中传导离子协同输运的第一性原理分子动力学研究

NASICON结构家族（通式为AxM2(XO4)3）是一类有应用前景固态电解质和电极体系。根据A或者M选择的不同，其可以做为锂/钠/钾/多价/混合离子固态电解质或电极材料。Li3Zr2Si2PO12及Na3Zr2Si2PO12中Zr为具有稳定的+4价氧化态，因此其分别被用作锂/钠离子固态电解质；基于V3+/V4+氧化还原反应且存在两种传导离子的Li2NaV2(PO4)3、ZnxNaV2(PO4)3及ZnxLiV2(PO4)3可被用为混合离子电池电极材料。然而，这五种NASICON结构化合物中离子输运的微观物理图像尚未明晰。本项目拟通过第一性原理分子动力学模拟研究以上五种NASICON结构化合物中同种/异种传导离子协同输运问题，揭示协同输运程度与离子输运性能之间的关联规律，继而提出基于协同输运效应的离子输运性能调控策略。

The NASICON-structure family, of general formula AxM2(XO4)3, is a class of promising solid electrolytes or electrode systems. Depending on A cations and M metals, the NASICON-structure compounds can serve as electrolyte and electrode in Li-/Na-/K-/polyvalent-/duel-ion batteries. Li3Zr2Si2PO12 and Na3Zr2Si2PO12 in which zirconium is at its stable oxidation states +4 are regarded as electrolyte for solid state Li-/Na-ion battery, respectively. Li2NaV2(PO4)3 ZnxNaV2(PO4)3 and ZnxLiV2(PO4)3 based on the V3+/V4+ redox reaction and with two types of A cations are used as electrode in duel-ion battery. However, the microscopic physical image of ion transport for these five systems remains unknown. In this project, we will investigate the concerted migration with the same type of ions in Li3Zr2Si2PO12 and Na3Zr2Si2PO12 and with the different types of ions in Li2NaV2(PO4)3, ZnxNaV2(PO4)3 and ZnxLiV2(PO4)3 by ab initio molecular dynamics simulations, revealing the relationship between the degree of concerted migrations and the ion transport properties, and thus proposing the regulating strategy for the ion transport properties based on the concerted migration effects.