Title: Nanoscale Compositional Mapping of Commercial LiNi_0.8Co_0.15Al_0.05O₂ Cathodes Using Atom Probe Tomography

Abstract

Nickel-rich cathodes provide improved specific capacity that lead to higher gravimetric energy density, critical for electric vehicles. However, poor long-term capacity retention at elevated temperatures/high C-rates (the rate of charge and discharge on a battery) stem from material issues: surface phase changes, corrosive side reactions with the electrolyte, ion dissolution and propagation of cracks. Introducing dopants, developing nanoscale surface coatings and graded core-shell structures have all improved the electrochemical performance of nickel-rich cathodes. However, a material level understanding on the effect of Li composition and distribution in Ni-rich cathodes is limited, due to a lack of characterization methods available that can directly image Li at the nanoscale. Hence, it is critical to establish methods such as atom probe tomography (APT), having both nanometer scale spatial resolution and high compositional sensitivity to quantitatively analyze battery cathodes. To fully realize its potential as a method for quantitative compositional analysis of commercial Li-ion batteries, we provide a comprehensive description of the challenges in sample preparation and analyze the dependency of the analysis parameters, specifically laser pulse energy on the measured stoichiometry of elements in a high Ni content cathode material; LiNi_0.8Co_0.15Al_0.05O₂ (NCA). In this work, our findings show the stoichiometry variations cannot bemore » explained by charge state ratios or Ga implantation damage alone during FIB preparation, indicating that additional factors such as crystallographic orientation may need to be considered to achieve quantitative nanoscale compositional analysis of such battery cathodes using APT.« less

Authors:

Parikh, Pritesh A. ^[1]; Chung, Hyeseung ^[1]; Vo, Ethan A. ^[2]; Banerjee, Abhik ^[3]; Meng, Ying Shirley  ^[4];

• Search DOE PAGES for author "Meng, Ying Shirley"
• Search DOE PAGES for ORCID "0000-0001-8936-8845"

Devaraj, Arun  ^[2]

• Search DOE PAGES for author "Devaraj, Arun"
• Search DOE PAGES for ORCID "0000-0003-1314-6212"

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+ Show Author Affiliations

1. Univ. of California San Diego, La Jolla, CA (United States)
2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
3. Univ. of California San Diego, La Jolla, CA (United States); TCG Centres for Research and Education in Science and Technology (TCG CREST), Kolkata (India). Research Institute for Sustainable Energy (RISE)
4. Univ. of Chicago, IL (United States); Univ. of California San Diego, La Jolla, CA (United States)

Publication Date:

Fri Jul 22 00:00:00 EDT 2022

Research Org.:

Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Energy Frontier Research Centers (EFRC) (United States). NorthEast Chemical Center for Energy Storage (NECCES)

Sponsoring Org.:

National Science Foundation (NSF); USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1922041

Report Number(s):

PNNL-SA-174918
Journal ID: ISSN 1932-7447

Grant/Contract Number:  

AC05-76RL01830; ECCS-1542148; SC0012583

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physical Chemistry. C

Additional Journal Information:

Journal Volume: 126; Journal Issue: 34; Journal ID: ISSN 1932-7447

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Electrodes; Energy; Lasers; Nanoparticles; Oxides