减少诱导的拓相过渡,以构建K2Mn[Fe(CN) 6 超级结构,用于高性能离子电池
Ruixue Wu1, Jie Lin2, Yang Shang1
1Key Laboratory of Advanced Functional Materials of Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, People's Republic of China.
Langmuir : the ACS journal of surfaces and colloids
|January 15, 2025
概括
研究人员开发了一种基于和的普鲁士蓝色类似物 (KMn-HCF) 的新立方超结构,用于离子电池. 这种设计提高了阴极的稳定性和耐用性,在1000个循环后实现了89.1%的容量保留.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 基于的普鲁士蓝色类似物 (KMn-HCF) 是离子电池 (SIB) 的有希望的阴极.
- 快速合成导致小KMn-HCF颗粒,导致表面积增加和电解质的有害副作用.
- 这些副作用会损害阴极电解质接口 (CEI),降低循环稳定性.
研究的目的:
- 设计一种策略,将小KMn-HCF粒子组装成一个稳定的超结构.
- 为了提高SIB中的KMn-HCF阴极的循环稳定性和耐用性.
- 调查结构和组成变化对电池性能的影响.
主要方法:
- 采用拓相位过渡策略,将KMn-HCF粒子组装成一个600nm立方超结构.
- 结构分析的重点是缺陷减少,CEI层均性,电解质接触最小化和结构完整性.
- 组合分析研究了Jahn-Teller扭曲和K+离子在框架稳定中的作用.
主要成果:
- 组装后的KMn-HCF立体超结构显示了显著改善的循环稳定性和耐用性.
- 该战略减少了缺陷,并提高了CEI层的统一性和稳定性.
- 下方Jahn-Teller扭曲和K+支柱效应防止了容量退化,在1000个循环后在0.1/0.5A g-1时实现了88.4%/89.1%的容量保留.
结论:
- 拓相位过渡策略有效地为SIB阴极创建了一个强大的KMn-HCF立方超结构.
- 增强的CEI层和结构完整性有助于稳定的电化学性能和长周期寿命.
- 这种方法为开发用于离子电池的高性能KMn-HCF材料提供了可行的途径.
相关概念视频
03:45Formation of Complex Ions
23.2K
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
23.2K
02:42Ionic Crystal Structures
14.1K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
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...
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...
14.1K
02:48Ionic Bonding and Electron Transfer
41.2K
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
41.2K
03:02Colors and Magnetism
11.5K
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...
11.5K
02:10Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
9.1K
Alkynes can be reduced to trans-alkenes using sodium or lithium in liquid ammonia. The reaction, known as dissolving metal reduction, proceeds with an anti addition of hydrogen across the carbon–carbon triple bond to form the trans product. Since ammonia exists as a gas (bp = −33°C) at room temperature, the reaction is carried out at low temperatures using a mixture of dry ice (sublimes at −78°C) and acetone.
When dissolved in liquid ammonia, an alkali metal,...
When dissolved in liquid ammonia, an alkali metal,...
9.1K
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
41.4K
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,...
41.4K