用混合多价添加剂稳定阳极的表面和批量稳定:Ca (TFSI) 和Mg (TFSI)
Sohyun Park1, Haoyu Liu1, Joseph Quinn2
1Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
ACS applied materials & interfaces
|April 15, 2024
概括
将和多价酸添加到阳极中,可以稳定固体电解质介相 (SEI) 层. 这通过减少副作用来改善下一代离子电池的日历寿命.
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
- 电池技术 电池技术
背景情况:
- 阳极为下一代离子电池提供比石墨更高的容量.
- 阳极由于反应性离子形成不稳定的固体电解质介相 (SEI) 层而遭受较低的日历寿命.
- 不稳定的SEI层会导致电解质成分的不良副作用.
研究的目的:
- 调查混合 (Ca) 和 (Mg) 多价值作为阳极的电解质添加剂的使用.
- 通过减轻反应性和稳定SEI层来改善阳极的日历寿命.
- 为了了解这些混合盐对阳极的体积和表面性能的影响.
主要方法:
- 使用Ca和Mg多价的混合物作为阳极的电解质添加剂.
- 采用多种结构特征化技术来研究对阳极体积和表面的影响.
- 进行了硬币细胞测试,以评估日历寿命性能和副作用.
主要成果:
- 在现场,Ca和Mg离子形成了热力学稳定的四级Li-Ca-Mg-SiZintl相.
- 在颗粒上形成了一个更稳定,更密集的SEI层,保护它们免受副作用.
- 与基线相比,混合阴离子电解质的全细胞显示日历寿命增长,测量电流降低,电流泄漏减少.
结论:
- 混合的Ca和Mg离子通过形成稳定的Zintl相和坚固的SEI层,有效地稳定了阳极.
- 改进的SEI层减少了副作用,从而提高了日历寿命和电池性能.
- 结构分析证实,混合的阴离子添加剂减少了电极裂变和增强了阴离子迁移.
更多相关视频
相关概念视频
04:01Factors Affecting Solubility
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 Chȃtelier’s principle. Consider the dissolution of silver iodide:
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
01:26EDTA: Auxiliary Complexing Reagents
EDTA titrations are usually carried out in highly basic conditions, where the fully deprotonated form of EDTA, Y4−, actively complexes with the free metal ions in the solution. Several metal ions precipitate as hydrous oxide (hydroxides, oxides, or oxyhydroxides) under these conditions, lowering the concentration of free metal ions in the solution. For this reason, auxiliary complexing agents or ligands such as ammonia, tartrate, citrate, or triethanolamine are used in EDTA titrations to...
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
01:17Accelerators
Accelerators in concrete serve as admixtures to speed up the hardening process, enabling the concrete to achieve early strength faster. Although accelerators do not necessarily impact the time it takes concrete to set, they reduce this time in practice. A common accelerator is calcium chloride, which is particularly useful for hastening early strength development in cold weather or for rapid repair jobs that require quick heat generation after mixing.
The effectiveness of calcium chloride can...
The effectiveness of calcium chloride can...