固体和液体Li电解质之间的离子电荷转移的温度和度依赖 - - 系统LLZO:Ta/LiPF-EC-DMC,LATP/LiPF-EC-DMC和LLZO:Ta/LiBOB-DME-THF
Tobias Wekking1, Martin Finsterbusch2, Carsten Korte1
1Institute of Energy Technologies: Electrochemical Process Engineering (IET-4), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany. c.korte@fz-juelich.de.
Physical chemistry chemical physics : PCCP
|February 26, 2025
概括
研究液体和固体电解质之间的离子转移动力学表明,度决定了速度限制的步骤. 表面层的电阻显著影响性能,特别是对于LLZO:Ta,与LATP固体电解质相比.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 固态离子学 固态离子学
背景情况:
- 高效的离子 (Li+) 在液体固体接口上的传输对于先进的电池技术至关重要.
- 像LLZO:Ta和LATP这样的氧化陶电解质对固态电池充满希望.
- 了解接口动力学是优化电池性能和防止降解的关键.
研究的目的:
- 为了研究Li+从液体转移到固体电解质的电化学动力学.
- 为了确定控制Li+在电解质接口上的运输的速度限制步骤.
- 为了比较LLZO:Ta和LATP固体电解质与普通液体电解质的界面特性.
主要方法:
- 应用了直流 (DC) 极化来测量电流密度 (i) 与电化学电位下降 (ΔμLi).
- 在LLZO:Ta和LATP固体电解质与LiPF6在EC/DMC和LiBOB在THF/DME液体电解质中配对.
- 使用欧姆电阻和巴特勒-沃尔默类离子转移过程的组合来建模结果.
主要成果:
- +转移速率在低液体电解质度下受到巴特勒-沃尔默类工艺的限制,在高度下受到低导电性表面层的限制.
- 表面层的面积电阻为25°C的LLZO:Ta的~600 Ω cm2,比LATP高三倍.
- 表面层中离子运输的激活能量大约是大量固体电解质的两倍.
结论:
- 固体电解质的表面层显著阻碍了Li+的转移,LLZO:Ta比LATP具有更高的阻力.
- 优化固体电解质表面和理解度依赖的动力学对于提高电池性能至关重要.
- 该研究提供了对界面电荷传递机制的洞察,具有对称的过渡状态 (α ≈ 1/2).
相关概念视频
03:13Intermolecular Forces
57.2K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
57.2K
02:48Ionic Bonding and Electron Transfer
40.8K
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.
40.8K
02:42Aqueous Solutions and Heats of Hydration
14.3K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
14.3K
01:12Ionic Strength: Overview
1.2K
The ionic strength of a solution is a quantitative way of expressing the total electrolyte concentration of a solution. This concept was first introduced in 1921 by two American physical chemists, Gilbert N. Lewis and Merle Randall, while describing the activity coefficient of strong electrolytes. During the calculation of ionic strength (I or μ), all the cations and anions are considered. However, the concentration (c) of an ion with a greater charge number (z) has a greater contribution...
1.2K
03:24Common Ion Effect
40.9K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Châtelier’s principle. Consider the dissolution of silver iodide:
40.9K
01:19Ionic Strength: Effects on Chemical Equilibria
1.3K
The addition of an inert ionic compound increases the solubility of a sparingly soluble salt. For example, adding potassium nitrate to a saturated solution of calcium sulfate significantly enhances the solubility of calcium sulfate. Le Châtelier's principle cannot predict this shift in the equilibrium. Instead, this could be explained in terms of changes in the effective concentration of the ions in solution in the presence of added inert salt.
In this solution, the primary...
In this solution, the primary...
1.3K