Development of Electrolytes for Single Crystal NMC532/Artificial Graphite Cells with Long Lifetime. Issue 3 (7th March 2018)

• Record Type: Journal Article
• Authors: Li, Jing; Li, Hongyang; Stone, Will; Glazier, Stephen; Dahn, J. R.
• Is Part Of: Journal of the Electrochemical Society. Volume 165:Issue 3(2018)
• Page Start: A626
• Page End: A635
• Publication Date: 2018-03-07
• Subjects: Electrolyte additives -- high precision coulometry -- Long lifetime cells; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0971803jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : NMC532/artificial graphite cells using single crystal NMC532 active material can have excellent long term lifetime at 4.4 V and elevated temperature if appropriate electrolytes are used. However, electrolytes developed earlier for these cells and reported in the literature cannot support even C/2 rates during charging without unwanted lithium plating at room temperature. This work is thus focused on the development of new electrolytes for single crystal NMC532/artificial graphite cells that can yield long lifetime and support higher charging rates. Ex-situ and in-situ gas measurements, ultra-high precision coulometry, isothermal microcalorimetry, lithium plating tests and long term cycling tests were used for the screening of electrolytes. Electrolytes with 2% vinylene carbonate (VC) + 1% ethylene sulfate (DTD) additives or 2% fluoroethylene carbonate (FEC) + 1% DTD additives yield single-crystal NMC532/graphite cells with long lifetime that can support C-rate charging at 20°C.