氧气二元化驱动的阳离子迁移诱导了无序岩盐阴极中的电压歇斯底里
Byunghoon Kim1,2, Peichen Zhong1, Yunyeong Choi3
1Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|December 19, 2024
概括
富含的阴极中的电压歇斯底里不是直接由氧二元化引起的,而是间接由过渡金属迁移引起的. 这一发现为提高电池性能提供了新的见解.
科学领域:
- 材料科学
- 电化学
- 电池技术
背景情况:
- 丰富的阴极通过利用氧氧还原提供更高的能量密度.
- 由于结构变化和电压歇斯底里阻碍了实际应用.
- 过渡金属 (TM) 迁移和氧气二元化在歇斯底里的作用尚未完全理解.
研究的目的:
- 在丰富的石盐阴极中阐明电压歇斯底里的机械起源.
- 要区分氧气二元化和TM迁移对hysteresis的贡献.
- 为减轻先进电池材料中的电压歇斯底里提供洞察力.
主要方法:
- 研究了一种富含的具有代表性的岩盐阴极 (Li1.2Mn0.4Ti0.4O2).
- 分析电化学过程以了解结构转变.
- 利用机械学的洞察力来区分氧气二元化和TM迁移的作用.
主要成果:
- 氧二极体的形成和裂变是快速的,这表明它们不是歇斯底里的直接原因.
- 氧二极体通过诱导TM迁移间接加剧歇斯底里.
- TM迁移是一种较慢的过程,通过能量消散和阴离子重排,对歇斯底里产生显著影响.
结论:
- 富含的阴极中的电压歇斯底里主要是由过渡金属迁移驱动的,而不是氧气二元化.
- 了解这种机制可以制定有针对性的降低hysteresis的策略.
- 这项研究为更实用,更稳定的高能材料铺平了道路.
相关概念视频
Electrolysis
26.0K
In a galvanic cell, the electrical work is done by a redox system on its surroundings as electrons produced by the spontaneous redox reactions are transferred through an external circuit. Alternatively, an external circuit does work on a redox system by imposing a voltage sufficient to drive an otherwise nonspontaneous reaction in a process known as electrolysis. For instance, recharging a battery involves the use of an external power source to drive the spontaneous (discharge) cell reaction in...
26.0K
Ionic 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
Voltaic/Galvanic Cells
56.8K
Spontaneous Chemical Reactions
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
Spontaneous redox reactions occur abundantly in nature. The chemical reaction occurring in a disposable AA battery powering our remote controls is one such example of a spontaneous redox reaction. Another example is the immersion of coiled copper wire into an aqueous silver nitrate solution. The reaction shows a gradual, visually impressive color change from colorless to bright blue and the formation of a grey precipitate on the copper wire. In this experiment,...
56.8K
Ionic 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
Crystal Field Theory - Octahedral Complexes
26.1K
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...
26.1K
Standard Electrode Potentials
43.4K
On comparing the reactivity of silver and lead, it is observed that the two ionic species, Ag+ (aq) and Pb2+ (aq), show a difference in their redox reactivity towards copper: the silver ion undergoes spontaneous reduction, while the lead ion does not. This relative redox activity can be easily quantified in electrochemical cells by a property called cell potential. This property is commonly known as cell voltage in electrochemistry, and it is a measure of the energy which accompanies the charge...
43.4K


