Jump to main content
Jump to site search


Revealing electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries by in situ Fourier transform infrared spectroscopy

Author affiliations

Abstract

Understanding (electro-)chemical reactions at the electrode–electrolyte interface (EEI) is crucial to promote the cycle life of lithium-ion batteries. In this study, we developed an in situ Fourier-transform infrared spectroscopy (FT-IR) method, which provided unprecedented information on the oxidation of carbonate solvents via dehydrogenation on LiNixMnyCo1−xyO2 (NMC). While ethylene carbonate (EC) was stable against oxidation on Pt up to 4.8 VLi, unique evidence for dehydrogenation of EC on LiNi0.8Co0.1Mn0.1O2 (NMC811) at voltages as low as 3.8 VLi was revealed by in situ FT-IR measurements, which was supported by density functional theory (DFT) results. Unique dehydrogenated species from EC were observed on NMC811 surface, including dehydrogenated EC anchored on oxides, vinylene carbonate (VC) and dehydrogenated oligomers which could diffuse away from the surface. Similar dehydrogenation on NMC811 was noted for EMC-based and LP57 (1 M LiPF6 in 3 : 7 EC/EMC) electrolytes. In contrast, no dehydrogenation was found for NMC111 or surface-modified NMC by coatings such as Al2O3. In addition, while the dehydrogenation of solvents was observed in 1 M electrolytes with different anions, they were not observed on NMC811 in the concentrated electrolyte (EC/EMC with 3.1 M LiPF6), indicating lithium coordination could suppress dehydrogenation. Dehydrogenation of carbonates on NMC811 accompanied with rapid growth of interfacial impedance with increasing voltage revealed by electrochemical impedance spectroscopy (EIS), while the electrode–electrolyte combinations without dehydrogenation did not show significant impedance growth. Therefore, minimizing carbonate dehydrogenation on the NMC surface by tuning electrode reactivity and electrolyte reactivity is critical to develop high-energy Li-ion batteries with long cycle life.

Graphical abstract: Revealing electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries by in situ Fourier transform infrared spectroscopy

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 Aug 2019, accepted on 18 Nov 2019 and first published on 18 Nov 2019


Article type: Paper
DOI: 10.1039/C9EE02543J
Energy Environ. Sci., 2020, Advance Article
  • Open access: Creative Commons BY license
  •   Request permissions

    Revealing electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries by in situ Fourier transform infrared spectroscopy

    Y. Zhang, Y. Katayama, R. Tatara, L. Giordano, Y. Yu, D. Fraggedakis, J. G. Sun, F. Maglia, R. Jung, M. Z. Bazant and Y. Shao-Horn, Energy Environ. Sci., 2020, Advance Article , DOI: 10.1039/C9EE02543J

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements