Abstract
Despite the long-established rocking-chair theory of lithium-ion batteries (LIBs), developing novel characterization methodology with higher spatiotemporal resolution facilitates a better understanding of the solid electrolyte interphase studies to shape the reaction mechanisms. In this work, we develop a Xenon ion plasma focused ion beam (Xe+ PFIB)-based characterization technique to probe the cross-sectional interface of both ternary cathode and graphite anode electrodes, with the focus on revealing the chemical composition and distribution underneath the electrode surface by in-depth analysis of secondary ions. Particularly, the lithium fluoride is detected in the pristine cathode prior to contact with the electrolyte, reflecting that the electrode degradation is in the form of the loss of lithium inventory during electrode preparation. This degradation is related to the hydrolysis of the cathode material and the decomposition of the PVDF binder. Through the quantitative analysis of the transition-metal degradation products, manganese is found to be the dominant element in the newly formed inactive fluoride deposition on the cathode, while no transition metal signal can be found inside the anode electrode. These insights at high resolution implemented via a PFIB-based characterization technique not only enrich the understanding of the degradation mechanism in the LIBs but also identify and enable a high-sensitivity methodology to obtain the chemical survey at the subsurface, which will help remove the capacity-fade observed in most LIBs.
Original language | English |
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Pages (from-to) | 662-669 |
Number of pages | 8 |
Journal | Energy and Environmental Materials |
Volume | 5 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2022 |
Funding
The electrochemical part of the research done at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) under contract DE-AC05-00OR22725, was sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office. T.S. acknowledges the support from the EPSRC project (EP/P001521/1) “Integrated Plasma Source Focused Ion Beam with Scanning Electron Microscope.” Y.Z. acknowledges support from EPSRC project (EP/V002260/1), UK National Measurement System and ISCF Measurement Fellowship. X.Y. and Y.Z. would like to thank Dr Juyeon Park from National Physical Laboratory (UK) for the discussion and suggestions. The authors declare no conflict of interest. The electrochemical part of the research done at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) under contract DE‐AC05‐00OR22725, was sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office. T.S. acknowledges the support from the EPSRC project (EP/P001521/1) “Integrated Plasma Source Focused Ion Beam with Scanning Electron Microscope.” Y.Z. acknowledges support from EPSRC project (EP/V002260/1), UK National Measurement System and ISCF Measurement Fellowship. X.Y. and Y.Z. would like to thank Dr Juyeon Park from National Physical Laboratory (UK) for the discussion and suggestions.
Funders | Funder number |
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ISCF | |
National Measurement System | |
U.S. Department of Energy | DE‐AC05‐00OR22725 |
Office of Energy Efficiency and Renewable Energy | |
Oak Ridge National Laboratory | |
UT-Battelle | |
Engineering and Physical Sciences Research Council | EP/P001521/1, EP/V002260/1 |
National Physical Laboratory |
Keywords
- degradation
- lithium-ion battery
- mass spectrometry
- plasma focused ion beam
- subsurface