空位增强了石墨烯上Li,Na和K的聚合
Jonathon Cottom1,2, Qiong Cai3, Emilia Olsson1,2
1Advanced Research Center for Nanolithography Science Park 106 Amsterdam 1098 XG The Netherlands.
概括
石墨烯中的碳空缺促进性金属聚合,这是树突形成的关键步骤,影响电池的安全性和寿命. 了解这些机制对于开发更安全,高性能电池至关重要.
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
- 计算化学计算化学
背景情况:
- 在金属离子电池中形成金属石的形成损害了循环寿命和安全性.
- 表面缺陷被怀疑会促进不均的金属核,但原子尺度的机制尚不清楚.
研究的目的:
- 研究碳单空 (VC) 对金属 (Li,Na,K) 在石墨烯上的聚合物的影响.
- 澄清金属聚类和随后的树突形成的缺陷促进途径.
主要方法:
- 使用第一原则计算,研究原始和有缺陷的石墨烯表面上的金属集群 (n=1-12).
- 分析了金属集群的稳定性及其与石墨烯的结合相互作用.
主要成果:
- 在原始石墨烯上,Li集群形成受到阻碍,K集群被抑制,Na呈现自发集群.
- 碳单空气通过增强表面结合和修改电荷定位来稳定小金属集群 (n ≤ 3).
- 空隙促进Li的早期核化,在较低的负载下促进Na的生长,并在较小的尺寸上有利于K集群.
结论:
- 碳单 vacancies 显著改变金属集群行为在石墨烯上,促进树石前体的形成.
- 对缺陷促成的聚类的原子学见解可以指导抗石碳阳极的设计,以提高电池性能和安全性.
相关概念视频
Electron Configuration of Multielectron Atoms
37.7K
The alkali metal sodium (atomic number 11) has one more electron than the neon atom. This electron must go into the lowest-energy subshell available, the 3s orbital, giving a 1s22s22p63s1 configuration. The electrons occupying the outermost shell orbital(s) (highest value of n) are called valence electrons, and those occupying the inner shell orbitals are called core electrons. Since the core electron shells correspond to noble gas electron configurations, we can abbreviate electron...
37.7K
Ionic Crystal Structures
14.0K
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...
14.0K
Valence Bond Theory
8.4K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
8.4K
Ionic Bonding and Electron Transfer
39.8K
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.
39.8K
Trends in Lattice Energy: Ion Size and Charge
23.5K
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
23.5K
Crystal Field Theory - Octahedral Complexes
25.8K
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...
25.8K


