在晶体和无形NaMOCl4 (M = Nb, Ta) 固体电解质中超离子导电性的微观机制
Grace Wei1,2, Luca Binci1,2, Gerbrand Ceder1,2
1Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, California 94720, United States.
无序的化固体电解质,与有序的晶体相不同,可实现高效的离子运输. 这项研究表明,以为基础的电解质的结构障碍是下一代电池高导电性的关键.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 计算化学计算化学
背景情况:
- 离子固体电解质对于可持续的能源储存至关重要.
- 基于化物的NaMOCl4材料显示出有前途,但缺乏明确的结构-运输理解.
- 结晶性的实验挑战掩盖了NaMOCl4.4的行为.
研究的目的:
- 阐明晶体和无形NaMOCl4.4中的结构-运输关系.
- 研究这些材料中控制离子导电性的机制.
- 确定用于增强离子导电性的设计原则.
主要方法:
- 密度函数理论 (DFT) 的计算.
- 机器学习分子动力学 (MLMD) 模拟.
- 对离子扩散通路和激活障碍的分析.
主要成果:
- 晶体NaMOCl4由于高激活障碍在秩序-混乱过渡下表现出低导电性.
- 在过渡的上方,晶体相中的链动力学增强了的运输.
- 无形NaMOCl4通过框架灵活性表现出容易的三维扩散.
结论:
- 在有序的晶体相中,离子运输受到阻碍,但在无序状态下,离子运输得到了促进.
- 热或结构障碍对于纳化电解质的高导电性至关重要.
- 这些发现修改了系统的假设,并指导了先进的离子电池的设计.
更多相关视频
08:55Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
08:12Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
Published on: December 5, 2015
相关概念视频
Molecular and Ionic Solids
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Theory of Metallic Conduction
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
Superconductor
Electrolytes: van't Hoff Factor
The colligative properties of a solution depend only on the number, not on the identity, of solute species dissolved. The concentration terms in the equations for various colligative properties (freezing point depression, boiling point elevation, osmotic pressure) pertain to all solute species present in the solution. Nonelectrolytes dissolve physically without dissociation or any other accompanying process. Each molecule that dissolves yields one...
