在Li2B12H12固体电解质中,有序-无序相变和离子导电性
Alexey P Maltsev1, Ilya V Chepkasov1, Artem R Oganov1
1Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, Moscow 121205, Russia.
ACS applied materials & interfaces
|September 1, 2023
概括
机器学习潜力精确模拟了Li2B12H12和LiCB11H12中的相位过渡和离子导电性. 模拟显示,离子重定向运动是Li2B12H12中秩序-混乱过渡的关键.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 固态物理 固态物理
背景情况:
- 了解固体电解质中的离子导电性和相变对于先进的电池技术至关重要.
- 二甲酸盐 (Li2B12H12) 和碳化物 (LiCB11H12) 是有希望的固体电解质候选物.
研究的目的:
- 模拟Li2B12H12和LiCB11H12的温度诱导的相变和离子导电性.
- 通过先进的计算方法,研究离子动力学在这些特性中的作用.
主要方法:
- 机器学习原子间潜力 (MLIP) 是使用范德瓦尔斯纠正密度函数理论 (rev-vdW-DF2) 开发的.
- 在超出2000个原子的系统上进行了初始质量的分子动力学模拟,用于纳米秒时间尺度.
主要成果:
- 模拟过渡温度,晶格参数,扩散,离子导电率和激活能量与实验数据密切匹配.
- 该研究强调了[B12H12]2-离子重定向运动在Li2B12H12的相位过渡中的关键作用.
- 在空位丰富的系统中,完全的离子旋转与理想晶体中有限的振动运动之间进行了区别.
结论:
- MLIP能够准确地模拟大规模系统和固体电解质的长时间尺度.
- 在Li2B12H12中,相变的特点是离子定向障碍的变化,而不是完全的动态障碍.
- 这些发现为这些材料中的离子传输机制提供了宝贵的见解.
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