Anti-corrosive and surface-stabilizing functional electrolyte containing LiFSI and LiPO2F2 for SiOx/NCM811-based batteries. (15th April 2022)

• Record Type: Journal Article
• Authors: Kim, Ji Won; Seong, Min Ji; Park, Dae Woon; Jeong, Goojin; Yim, Taeeun
• Is Part Of: Corrosion science. Volume 198(2022)
• Publication Date: 2022-04-15
• Subjects: Lithium-ion batteries -- Silicon oxide -- Lithium bis(fluoromenthansulfonyl)imide -- Lithium difluorophosphate -- Electrolyte -- Corrosion inhibitor; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110117
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Silicon oxide (SiO x ) has attracted considerable attention as an advanced anode material; however, SiO x becomes extensively pulverized during an electrochemical process, resulting in increased resistances. To address this issue, it is proposed the use of effective electrolyte additives, the combination of lithium bis(fluoromethanesulfonyl)imide (LiFSI) and lithium difluorophosphate (LiPO2 F2 ). LiFSI allowed for the stable cycling of the SiO x anode by forming LiF-based solid–electrolyte interphases. Meanwhile, LiPO2 F2 effectively suppressed undesirable LiFSI-induced corrosion reactions at the cathode also by forming stable cathode–electrolyte interphases on the surface of the Al current collector. Consequently, the cell cycled with LiFSI/LiPO2 F2 -containing electrolyte exhibited improved cycling retention (94.6%). Graphical Abstract: ga1 Highlights: ● LiFSI makes robust SEI layer on the SiO x anode via electrochemical reaction. ● LiFSI-derived artificial SEI layer suppresses pulverization of SiO x anode materials. ● Al-corrosion at cathode triggered by LiFSI can be stabilized by employing LiPO2 F2. ● LiFSI/LiPO2 F2 -combined additives improve cycling performance of SiO x /NCM cells. ● Role of each additive is analyzed in terms of chemical/electrochemical reactivity.