揭示了Ni-丰富阴极中的零下温度电化学动力学行为
Fanbo Meng1,2, Haolin Zhang1,2, Xingyu Xiong1,2
1School of Materials Science and Engineering, Guangdong Provincial Key Laboratory of Advanced Energy Storage Mater., South China University of Technology, Guangzhou, 510640, China.
Small (Weinheim an der Bergstrasse, Germany)
|August 31, 2023
概括
零度以下的温度阻碍了富含Ni的阴极性能,原因是厚厚的阴极电解质介相 (CEI) 膜形成和不完整的结构变化,减缓电荷存储和减少容量.
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
- 储能 储能 储能 储能 储能 储能
背景情况:
- 富含的阴极在零度以下的温度下表现出缓慢的动力学,导致特定容量减少和速率能力差.
- 导致这种性能下降的根本机制尚不清楚.
研究的目的:
- 为了阐明低于零度温度下丰富的阴极性能下降背后的驱动力.
- 调查阴极电解质介相 (CEI) 膜形成和结构演变的作用.
主要方法:
- 在现场进行X射线衍射 (XRD) 来监测结构变化.
- 飞行时间二次离子质谱 (TOF-SIMS) 分析表面化学.
主要成果:
- 在零度以下的温度下循环时,CEI膜的持续积累和不完整的结构演变发生.
- 一个厚厚的,均的CEI膜阻断了Li+离子扩散,导致不完整的相位演变和电荷潜在延迟.
- 不完整的相位演变导致放电深度低,可逆性差,初始库伦比效率低.
结论:
- 在零度以下的温度下,CEI薄膜形成和不完整的相位演变是限制Ni丰富阴极中电化学动学的关键因素.
- 了解这些影响对于在寒冷环境中推进丰富阴极的应用至关重要.
相关概念视频
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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.
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Nonstandard Reaction Conditions
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
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