It has always been a challenging problem to conduct research on low temperature aluminum electrolyte KF-NaF-AlF₃-Al₂O₃ because of high temperature and strong corrosiveness in aluminum electrolysis industry. Fortunately, the rapid advancement of computational materials science provides us with a good tool to study it. In this paper, the ionic micro-structure and transport properties of KF-NaF-AlF₃-Al₂O₃ system are studied by adopting first-principles molecular dynamics simulation directly. The calculated results show that the complex ion groups in KF-NaF-AlF₃-Al₂O₃ system are mainly [AlF₄]⁻, [AlF₅]²⁻ and [AlF₆]³⁻, meantime, with the increasing concentration of Al₂O₃, [AlF₄] ⁻ decreases but the coordination number of Al-F complex ion groups increases gradually. Intricate complex ion groups of Al-F-Al, Al-O-Al and Al-O-F are formed on account of the presence of bridge F and bridge O ions. Besides, the proportion of bridge F and Bridge O ions increases with the increasing concentration of Al₂O₃, and the ionic micro-structure of the system becomes more intricate than before, reducing the ionic conductivity and increasing the viscosity of the system. This study can provide a useful guide for designing suitable low temperature electrolyte system in aluminum electrolysis production.

由于铝电解工业中的高温和强腐蚀性，对低温铝电解质KF-NaF-AlF ₃ -Al ₂ O ₃进行研究一直是一个具有挑战性的问题。幸运的是，计算材料科学的飞速发展为我们提供了研究它的良好工具。本文直接通过第一性原理分子动力学模拟研究了KF-NaF-AlF ₃ -Al ₂ O ₃体系的离子微结构和输运性能。计算结果表明，KF-NaF-AlF ₃ -Al ₂ O ₃体系中的复合离子基团主要为[AlF ₄] ^-，[的AlF ₅ ] ^2-和[的AlF ₆ ] ^3-，同时，用Al浓度的增加₂ ö ₃，[的AlF ₄ ] ^-减小但复杂的AlF离子基增加配位数逐渐。由于桥F和桥O离子的存在，形成了Al-F-Al，Al-O-Al和Al-OF的复杂的复合离子基团。此外，随着Al ₂ O ₃浓度的增加，桥F和桥O离子的比例增加。，并且系统的离子微结构比以前更加复杂，从而降低了离子电导率并增加了系统的粘度。该研究可为设计铝电解生产中合适的低温电解液系统提供有用的指导。