Lithium Bis(fluorosulfony)imide-Lithium Hexafluorophosphate Binary-Salt Electrolytes for Lithium-Ion Batteries: Aluminum Corrosion Behaviors and Electrochemical Properties

Xia, Lan; Jiang, Yabei; Pan, Yueyang; Li, Shiqi; Wang, Jason; He, Yiting; Xia, Yonggao; Liu, Zhaoping; Chen, George Z.

Abstract

© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Aluminum corrosion behaviors and electrochemical properties of Lithium bis(fluorosulfony)imide (LiFSI)-lithium hexafluorophosphate (LiPF6) binary-salt electrolytes containing mixtures of LiFSI and LiPF6 (with a total salt content of 1.2 mol L−1) with different molar ratios in EC/EMC (3:7, by vol.) solutions are systematically investigated. Our experimental results from cyclic voltammetry, scanning electron microscopy (SEM), chronoamperometry and the charge-discharge measurements of Li/LiNi1/3Co1/3Mn1/3O2 half-cells demonstrate that the LiFSI-LiPF6 binary-salt electrolytes with the LiFSI concentrations lower than 0.3 mol L−1 exhibit not only passivating aluminum current collectors at 4.3 V vs. Li+/Li, but also improved cycling performance. Meanwhile, Artificial Graphite/LiNi1/3Co1/3Mn1/3O2 (AG/NMC111) pouch cells made with the LiFSI(0.2)-LiPF6 (1.0) electrolyte with the LiFSI concentration of 0.2 mol L−1 display an excellent cycling stability with 93.9% capacity retention at 1 C rate after 360 cycles, and enhanced capacity retention at −20 °C, 60 °C and after 55 °C storage for 30 days compared to cells with 1.2 mol L−1 LiPF6/EC-EMC conventional electrolyte. This work confirms that binary-salt electrolytes system, such as LiFSI-LiPF6, may be a promising method to enhance the longevity and storage properties of Li-ion batteries.

Citation

Xia, L., Jiang, Y., Pan, Y., Li, S., Wang, J., He, Y., Xia, Y., Liu, Z., & Chen, G. Z. (2018). Lithium Bis(fluorosulfony)imide-Lithium Hexafluorophosphate Binary-Salt Electrolytes for Lithium-Ion Batteries: Aluminum Corrosion Behaviors and Electrochemical Properties. ChemistrySelect, 3(7), 1954-1960. https://doi.org/10.1002/slct.201702488

• Journal Article Type: Article
• Acceptance Date: Jan 26, 2018
• Publication Date: Feb 21, 2018
• Deposit Date: May 27, 2020
• Journal: ChemistrySelect
• Electronic ISSN: 2365-6549
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Issue: 7
• Pages: 1954-1960
• DOI: https://doi.org/10.1002/slct.201702488
• Public URL: https://nottingham-repository.worktribe.com/output/3213214
• Publisher URL: https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/slct.201702488