Title: Morphological and Electrochemical Characterization of Nanostructured Li₄Ti₅O₁₂ Electrodes Using Multiple Imaging Mode Synchrotron X-ray Computed Tomography

Abstract

In this study, synchrotron X-ray computed tomography has been utilized using two different imaging modes, absorption and Zernike phase contrast, to reconstruct the real three-dimensional (3D) morphology of nanostructured Li₄Ti₅O₁₂ (LTO) electrodes. The morphology of the high atomic number active material has been obtained using the absorption contrast mode, whereas the percolated solid network composed of active material and carbon-doped polymer binder domain (CBD) has been obtained using the Zernike phase contrast mode. The 3D absorption contrast image revealed that some LTO nano-particles tend to agglomerate and form secondary micro-sized particles with varying degrees of sphericity. The tortuosity of electrode’s pore and solid phases were found to have directional dependence, different from Bruggeman’s tortuosity commonly used in macro-homogeneous models. The electrode’s heterogeneous structure was investigated by developing a numerical model to simulate galvanostatic discharge process using the Zernike phase contrast mode. The inclusion of CBD in the Zernike phase contrast results in an integrated percolated network of active material and CBD that is highly suited for continuum modeling. As a result, the simulation results highlight the importance of using the real 3D geometry since the spatial distribution of physical and electrochemical properties have a strong non-uniformity due to microstructural heterogeneities.

Authors:

Kashkooli, Ali Ghorbani  ^[1];

• Search DOE PAGES for author "Kashkooli, Ali Ghorbani"
• Search DOE PAGES for ORCID "0000-0002-0638-7133"

Foreman, Evan ^[2]; Farhad, Siamak ^[2]; Lee, Dong Un ^[1]; Feng, Kun  ^[1];

• Search DOE PAGES for author "Feng, Kun"
• Search DOE PAGES for ORCID "0000-0003-4854-5731"

Lui, Gregory ^[1]; De Andrade, Vincent ^[3]; Chen, Zhongwei ^[1]

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+ Show Author Affiliations

1. Univ. of Waterloo, Waterloo, ON (Canada)
2. Univ. of Akron, Akron, OH (United States)
3. Argonne National Lab. (ANL), Lemont, IL (United States)

Publication Date:

Thu Sep 21 00:00:00 EDT 2017

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

University of Akron; Natural Sciences and Engineering Research Council of Canada (NSERC); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1402041

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the Electrochemical Society

Additional Journal Information:

Journal Volume: 164; Journal Issue: 12; Journal ID: ISSN 0013-4651

Publisher:

The Electrochemical Society

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Image based modeling; Lithium-ion battery; Synchrotron X-ray computed tomography; Tortuosity; Lithium titanate oxide