溶解
电解质
阳极
磷酸铁锂
X射线荧光
材料科学
碳酸盐
电极
阴极
沉积(地质)
分析化学(期刊)
铁质
过渡金属
化学工程
石墨
钝化
荧光
化学
电化学
冶金
纳米技术
环境化学
图层(电子)
沉积物
古生物学
催化作用
物理化学
工程类
物理
生物化学
生物
量子力学
作者
Ahmed Eldesoky,Eric Logan,Michel B. Johnson,Christopher R.M. McFarlane,J. R. Dahn
出处
期刊:Journal of The Electrochemical Society
[The Electrochemical Society]
日期:2020-10-01
卷期号:167 (13): 130539-130539
被引量:23
标识
DOI:10.1149/1945-7111/abba62
摘要
Lithium iron phosphate (LiFePO 4 , or LFP) is a widely used cathode material in Li-ion cells due to its improved safety and low cost relative to other materials such as LiNi x Mn y Co z O 2 (x + y + z = 1, NMC). To improve the calendar life of LFP cells, an investigation of their failure mechanisms is necessary. Herein, we use scanning micro X-ray fluorescence ( μ XRF) to study Fe dissolution from LFP and deposition on the graphite electrode, which is thought to be a contributor to capacity fade. The impacts of the vinylene carbonate (VC) electrolyte additive, cycling conditions, and water content in the positive electrode on Fe dissolution were studied. There was no significant correlation between Fe dissolution and capacity fade found. Furthermore, we proposed that gas generation concomitant with Fe dissolution might be due to the reduction of the organic species coordinating Fe 2+ when they reach the negative electrode. Localized regions of increased Fe loading on the anode surface were found, which corresponded to regions with slight non-uniformities in stack pressure or current density. This work demonstrates the effectiveness of μ XRF in quantifying transition metal (TM) dissolution in Li-ion cells without any sample treatments that might mask valuable information such as element spatial distribution.
科研通智能强力驱动
Strongly Powered by AbleSci AI