Journal Article

FZJ-2023-00744

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Lithium Difluorophosphate: Boon for High Voltage Li Ion Batteries and a Bane for high Thermal Stability/low Toxicity: Towards Synergistic Dual‐Additives to Circumvent this Dilemma

Kubot, M. ; Frankenstein, L. ; Muschiol, E. ; Klein, S. ; Esselen, M. ; Winter, M.FZJ* ; Nowak, S. ; Kasnatscheew, J. (Corresponding author)FZJ*

2023
Wiley-VCH Weinheim

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Please use a persistent id in citations: doi:10.1002/cssc.202202189  doi:10.34734/FZJ-2023-00744

Abstract: The specific energy/energy density of state-of-the-art (SOTA) Li-ion batteries can be increased by raising the upper charge voltage. However, instability of SOTA cathodes (i. e., LiNiyCoxMnyO2; x+y+z=1; NCM) triggers electrode crosstalk through enhanced transition metal (TM) dissolution and contributes to severe capacity fade; in the worst case, to a sudden death (“roll-over failure”). Lithium difluorophosphate (LiDFP) as electrolyte additive is able to boost high voltage performance by scavenging dissolved TMs. However, LiDFP is chemically unstable and rapidly decomposes to toxic (oligo)organofluorophosphates (OFPs) at elevated temperatures; a process that can be precisely analyzed by means of high-performance liquid chromatography–high resolution mass spectroscopy. The toxicity of LiDFP can be proven by the well-known acetylcholinesterase inhibition test. Interestingly, although fluoroethylene carbonate (FEC) is inappropriate for high voltage applications as a single electrolyte additive due to rollover failure, it is able to suppress formation of toxic OFPs. Based on this, a synergistic LiDFP/FEC dual-additive approach is suggested in this work, showing characteristic benefits of both individual additives (good capacity retention at high voltage in the presence of LiDFP and decreased OFP formation/toxicity induced by FEC).

Note: Zudem gefördert durch: BMWK "Go3”(03ETE002D)

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Contributing Institute(s):

1. Helmholtz-Institut Münster Ionenleiter für Energiespeicher (IEK-12)

Research Program(s):

1. 1221 - Fundamentals and Materials (POF4-122) (POF4-122)
2. BMBF 03XP0311B - BatgasMod - Batteriegasungs-Modellierung (03XP0311B) (03XP0311B)

Appears in the scientific report 2023

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; DEAL Wiley ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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