通过Mg超高场NMR和第一原理计算揭示的抗矿固体电解质中的Mg离子导电
David M Halat1,2,3, Haoyu Liu4, Kwangnam Kim5,6
1Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|July 24, 2025
概括
离子电池可以提供更高的能量密度. 这项研究使用先进的25Mg固态NMR分析抗电解质,揭示了它们的结构和离子动态,以提高电池性能.
科学领域:
- 材料科学
- 电化学
- 固态化学
背景情况:
- 离子电池由于双价Mg2+离子具有比离子电池更高的能量密度.
- 然而,离子电池技术仍处于早期发展阶段.
- 固体电解质对于安全高效的电池运行至关重要.
研究的目的:
- 研究抗矿固体电解质 (Mg3SbN和Mg3AsN) 的局部结构和Mg离子动力学.
- 建立25Mg固态NMR作为检测这些材料的结构和动态特性的一种工具.
- 将NMR参数与结构特征和离子移动性相关联.
主要方法:
- 使用超高场 (35.2 T) 25Mg固态核磁共振 (ssNMR) 光谱.
- 进行了可变温度ssNMR测量和25Mg T1放松计.
- 使用第一原理计算来证实实验结果和预测属性.
主要成果:
- 报告了迄今为止最大的25Mg四极合常量 (CQ) (高达22MHz),与抗矿耐受性因子相关,并表明了格子扭曲.
- 由Mg离子运动引起的温度依赖的光谱变化.
- 与Mg3SbN相比,Mg3AsN阶段的Mg离子迁移的活性能量较低,符合计算预测.
结论:
- 25Mg ssNMR,特别是在超高电场下,是对抗矿固体电解质的局部结构和离子动态的有效特征.
- 格子扭曲影响Mg-离子的移动性,这表明Mg3AsN是进一步研究的有希望的候选物.
- 结合先进的核磁共振技术和计算方法对于推进超越电池材料研究至关重要.
相关概念视频
02:54Molecular and Ionic Solids
17.6K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
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...
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...
17.6K
01:31Ferromagnetism
2.5K
Materials like iron, nickel, and cobalt consist of magnetic domains, within which the magnetic dipoles are arranged parallel to each other. The magnetic dipoles are rigidly aligned in the same direction within a domain by quantum mechanical coupling among the atoms. This coupling is so strong that even thermal agitation at room temperature cannot break it. The result is that each domain has a net dipole moment. However, some materials have weaker coupling, and are ferromagnetic at lower...
2.5K
02:58Crystal Field Theory - Octahedral Complexes
27.9K
Crystal Field Theory
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...
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...
27.9K
01:17Theory of Metallic Conduction
1.4K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the 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,...
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,...
1.4K
01:31Magnetic Susceptibility and Permeability
1.4K
In linear magnetic materials, like paramagnets and diamagnets, magnetization is proportional to the magnetic field intensity. The constant of proportionality, a dimensionless number, is called magnetic susceptibility. The value of the susceptibility depends on the type of material.
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
1.4K
03:02Colors and Magnetism
12.3K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
12.3K