深充电的结构分析 (Ni0.95Co0.04Al0.01) 离子电池的O2阴极
Byung Cheol Lee1, Jeon Kim2, Hee-Soo Kim3
1Department of Battery Engineering, Hanyang University, Seoul, 04763, Korea.
ChemSusChem
|November 27, 2024
概括
,,,氧化 (NCA95) 阴极的高压充电会导致结构不稳定,包括相位过渡和微裂纹. 这限制了下一代电池的循环稳定性和容量保留.
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
- 固态化学 固态化学
背景情况:
- 尼克尔氧化 (LiNi0.95Co0.04Al0.01O2,NCA95) 是一个有希望的高能量密度电池的阴极材料.
- 在高度脱状态下了解其结构性行为对于提高电池性能和寿命至关重要.
研究的目的:
- 为了研究高化状态 (高达4.6V) 的NCA95阴极的结构稳定性.
- 确定在高压运行期间导致容量损失和循环降解的机制.
主要方法:
- 使用传输电子显微镜 (TEM) 来分析NCA95.5的结构演变.
- 阴极被充电到各种高电压,以诱导脱和观察结构变化.
主要成果:
- 局部化的 (Li) 离子耗尽触发了不可逆转的H3到H4相位过渡,观察到堆叠故障,即使在4.4V.
- 在4.3V以上,粒子内部形成微裂,损害机械完整性,导致快速循环降解.
- H3→H4相位过渡和微裂纹被确定为关键的故障机制.
结论:
- 对于循环NCA95而没有显著的容量损失,有一个明确的电压限制.
- 抑制Ni2+迁移到Li层的兴奋剂策略可以减轻相位过渡和抑制微裂变,增强阴极稳定性.
相关概念视频
Electrogravimetric Analysis: Overview
204
Electrogravimetric analysis measures the weight of an analyte deposited electrolytically onto a suitable working electrode. This method involves applying a potential to a pre-weighed electrode submerged in a solution, which results in the desired substance being deposited through reduction at the cathode or oxidation at the anode. The electrode's weight is recorded after deposition, and the difference in weight gives the analyte's weight in the solution.
To test the completeness of the...
To test the completeness of the...
204
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
Batteries and Fuel Cells
27.0K
A battery is a galvanic cell that is used as a source of electrical power for specific applications. Modern batteries exist in a multitude of forms to accommodate various applications, from tiny button batteries such as those that power wristwatches to the very large batteries used to supply backup energy to municipal power grids. Some batteries are designed for single-use applications and cannot be recharged (primary cells), while others are based on conveniently reversible cell reactions that...
27.0K
Formal Charges
32.3K
In some cases, there are seemingly more than one valid Lewis structures for molecules and polyatomic ions. The concept of formal charges can be used to help predict the most appropriate Lewis structure when more than one reasonable structure exists.
32.3K
Electrodeposition
603
Electrodeposition is a technique used to separate an analyte from interferents by electrochemical processes. Here, the analyte is a metal ion that can be deposited on an electrode immersed in the sample solution. The electrochemical setup consists of an anode and a cathode. When an electric current is applied to the setup, oxidation occurs at the anode. At the cathode, which consists of a large metal surface, metal ions undergo reduction and deposit onto the surface.
Electrodeposition can...
Electrodeposition can...
603
Lewis Structures of Molecular Compounds and Polyatomic Ions
34.5K
To draw Lewis structures for complicated molecules and molecular ions, it is helpful to follow a step-by-step procedure as outlined:
34.5K


