在不同电流密度下的阴极电解质接口的动态现场表征
Huanzhu Lv1,2, Lei Zhou1,2, Qisheng Fang1,2
1Institute of Fundamental and Frontier Science, University of Electronic Science and Technology of China, Chengdu, 611731, China.
Small (Weinheim an der Bergstrasse, Germany)
|May 28, 2024
概括
在金属电池 (LMB) 中的高阴极为电动汽车提供高能量密度. 这项研究表明,保护正极电解质接口 (CEI),特别是它们的无机组件,是快速充电期间稳定的关键.
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:
- 高含量阴极 (LiNi0.8Mn0.1Co0.1O2) 对于金属电池 (LMB) 的高能量密度至关重要,对于电动汽车 (EV) 至关重要.
- 在快速充电条件下,阴极电解质接口 (CEI) 的长期循环稳定性在LMB中仍然是一个重大挑战.
- 在高电流密度下,CEI和电解质的精确衰变机制尚未完全理解.
研究的目的:
- 研究电池循环期间CEI形成,消失和再生的动态过程.
- 了解增加电流密度对CEI稳定性和电池性能的影响.
- 确定增强CEI稳定性的策略,以提高LMB中的电化学性能.
主要方法:
- 现场福里埃变换红外光谱法 (FTIR) 用于监测充电和放电周期期间CEI的动态变化.
- 分析不同循环阶段和电流密度的CEI组件动态.
- CEI行为与电池整体性能指标的相关性.
主要成果:
- 动态CEI过程随着电流密度的增加而加剧,导致CEI由于连续的电解质反应而破裂,溶解和性能降低.
- 在低电流密度下,优良的容量保留与CEI内的无机化合物 (例如Li2CO3,LiF) 的丰富有关,促进稳定性和减少膨胀.
- 了解CEI组件的动态演变对于诊断性能限制至关重要.
结论:
- 在高电流密度下CEI的不稳定性是LMB性能下降的主要原因.
- 保护CEI,特别是其无机组件,对于实现卓越的电化学性能至关重要,尤其是在要求高的快速充电条件下.
- 专注于稳定CEI无机部分的战略有望促进LMB技术的发展.
相关概念视频
Interfacial Electrochemical Methods: Overview
237
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current...
237
Controlled-Current Coulometry: Overview
199
Controlled current coulometry, also known as amperostatic coulometry, is a technique used in electrochemical analysis to measure the quantity of a substance through the controlled passage of current. It involves the application of a constant current to an electrochemical cell containing the analyte of interest. As the current flows through the cell, the analyte undergoes a redox reaction at the electrode surface, resulting in a charge transfer. By monitoring the time required for a certain...
199
Electrolysis
26.3K
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...
26.3K
Electrogravimetric Analysis: Overview
220
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...
220
Voltammetry: Factors Affecting Measurements
151
A current produced due to the redox reactions of the analyte at the working and auxiliary electrodes is called a faradaic current. The reaction can be divided into two types. The current generated due to the reduction of the analyte is called cathodic current, and it carries a positive charge. In contrast, the current produced by analyte oxidation is known as an anodic current, and it has a negative charge. The applied potential at the working electrode determines the faradaic current flow, and...
151
Controlled-Potential Coulometry: Electrolytic Methods
160
Controlled-potential coulometry, also known as potentiostatic coulometry, employs a three-electrode system in which the working electrode's potential is precisely regulated using a potentiostat. Platinum working electrodes are utilized for positive potentials, while mercury pool electrodes are favored for extremely negative potentials. The platinum counter electrode is separated from the analyte using a membrane or salt bridge to avoid interference in the analysis.
The chosen potential...
The chosen potential...
160


