Visualizing nanoscale 3D compositional fluctuation of lithium in advanced lithium-ion battery cathodes.
The distribution of cations in Li-ion battery cathodes as a function of cycling is a pivotal characteristic of battery performance. The transition metal cation distribution has been shown to affect cathode performance; however, Li is notoriously challenging to characterize with typical imaging techniques. Here laser-assisted atom probe tomography (APT) is used to map the three-dimensional distribution of Li at a sub-nanometre spatial resolution and correlate it with the distribution of the transition metal cations (M) and the oxygen. As-fabricated layered Li1.2Ni0.2Mn0.6O2 is shown to have Li-rich Li2MO3 phase regions and Li-depleted Li(Ni0.5Mn0.5)O2 regions. Cycled material has an overall loss of Li in addition to Ni-, Mn- and Li-rich regions. Spinel LiNi0.5Mn1.5O4 is shown to have a uniform distribution of all cations. APT results were compared to energy dispersive spectroscopy mapping with a scanning transmission electron microscope to confirm the transition metal cation distribution.
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
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A
Devaraj
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
M
M
Gu
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
R
R
Colby
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
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P
Yan
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
C M
CM
Wang
Energy and Environmental Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
J M
JM
Zheng
Energy and Environmental Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
J
J
Xiao
FEI Company, 5350 NE Dawson Creek Dr., Hillsboro, Oregon 97124, USA.
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A
Genc
Energy and Environmental Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.
J G
JG
Zhang
Qatar Environment and Energy Research Institute, Qatar Foundation, PO box 5825, Doha, Qatar.
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I
Belharouak
Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
D
D
Wang
Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
K
K
Amine
Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, USA.|Qatar Environment and Energy Research Institute, Qatar Foundation, PO box 5825, Doha, Qatar.
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Thevuthasan