线性Jahn-Teller排序诱导"无缺陷"LiNiO中的单临床扭曲
George S Phillips1,2, James M A Steele1,3, Farheen N Sayed1,2
1Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Journal of the American Chemical Society
|July 31, 2025
概括
由于Jahn-Teller效应,氧化物表现出单体扭曲,影响其电池性能. 这种结构洞察力澄清了离子电池的特性和相位过渡.
科学领域:
- 材料科学
- 固态化学
- 电池技术
背景情况:
- 氧化 (LNO) 是高性能电池的关键阴极材料.
- 它的三角格子结构对量子磁学的研究很有兴趣.
- 在LNO中存在的缺陷和异构阻碍了基本的结构理解,并与本地探测数据产生差异.
研究的目的:
- 通过Na/Li离子交换合成的无缺陷LNO的结构.
- 调查LNO的结构扭曲和阶段过渡.
- 为LNO提供精细的结构模型,以帮助理解其特性.
主要方法:
- 使用X射线衍射 (XRD) 和中子粉衍射 (NPD) 来分析短距离和远距离结构.
- 使用可变温度XRD来研究相位过渡.
- 通过NaNiO2的Na/Li离子交换实现了"无缺陷"LNO的合成.
主要成果:
- 在100K的XRD和NPD布拉格反射中分离表明由合作对线Jahn-Teller扭曲驱动的单临床扭曲 (C2/m).
- 可变温度XRD显示了从单临床到体 (R-3m) 结构的第二阶段过渡在400K以上.
- 这项研究提出,这种对线的Jahn-Teller顺序存在于固态合成的LNO中,扭曲程度受缺陷度的影响.
结论:
- 离子交换的LNO在低温下表现出由于Jahn-Teller排序的单临床扭曲.
- 在较高的温度下,将阶段转换为方形结构.
- 这种结构理解对于推进LNO电子,磁性和电化学性能的研究至关重要.
更多相关视频
相关概念视频
02:33Lattice Centering and Coordination Number
9.9K
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
9.9K
02:37Metallic Solids
18.7K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
18.7K
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
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
44.7K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
44.7K
02:22Structures of Solids
14.7K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
14.7K
02:11Conformations of Cyclohexane
13.1K
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...
13.1K