%0 Journal Article
%A Weiling, Matthias
%A Lechtenfeld, Christian
%A Pfeiffer, Felix
%A Frankenstein, Lars
%A Diddens, Diddo
%A Wang, Jian-Fen
%A Nowak, Sascha
%A Baghernejad, Masoud
%T Mechanistic Understanding of Additive Reductive Degradation and SEI Formation in High‐Voltage NMC811||SiO x ‐Containing Cells via Operando ATR‐FTIR Spectroscopy
%J Advanced energy materials
%V 14
%N 5
%@ 1614-6832
%C Weinheim
%I Wiley-VCH
%M FZJ-2023-05297
%P 2303568
%D 2024
%X The implementation of silicon (Si)-containing negative electrodes is widely discussed as an approach to increase the specific capacity of lithium-ion batteries. However, challenges caused by severe volume changes and continuous (re-)formation of the solid-electrolyte interphase (SEI) on Si need to be overcome. The volume changes lead to electrolyte consumption and active lithium loss, decaying the cell performance and cycle life. Herein, the additive 2 sulfobenzoic acid anhydride (2 SBA) is utilized as an SEI-forming electrolyte additive for SiOx-containing anodes. The addition of 2 SBA to a state-of-the-art carbonate-based electrolyte in high-voltage NMC811||AG+20% SiOx pouch cells leads to improved electrochemical performance, resulting in a doubled cell cycle life. The origin of the enhanced cell performance is mechanistically investigated by developing an advanced experimental technique based on operando attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. The operando ATR-FTIR spectroscopy results elucidate the degradation mechanism via anhydride ring-opening reactions after electrochemical reduction on the anode surface. Additionally, ion chromatography conductivity detection mass spectrometry, scanning electron microscopy, energy dispersive X-ray analysis, and quantum chemistry calculations are employed to further elucidate the working mechanisms of the additive and its degradation products.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:001122818800001
%R 10.1002/aenm.202303568
%U https://juser.fz-juelich.de/record/1019323