Title: Impact of Stabilizing Cations on Lithium Intercalation in Tunneled Manganese Oxide Cathodes

Abstract

Stabilizing cations such as K⁺, Ba²⁺, and Ag⁺ are known to provide charge neutrality and enhance structural stability in low-cost tunneled manganese dioxide (MnO₂) cathodes for Li ion batteries. However, a fundamental understanding of the role of these cations in the electrochemical performance of tunneled MnO₂ cathodes remains unclear, especially at low stabilizing cation concentrations. Here, we employ density functional theory (DFT + U) calculations to reveal the impact of stabilizing potassium cation (K⁺) concentration on the structural stability, electronic properties, and kinetics of lithium transport in 2 x 2 tunneled manganese oxide (α-K_yMn₈O₁₆, at y = 0, 1, and 2) battery cathodes during lithium intercalation. Specifically, we provide insights into the effect of K⁺ ions on several critical factors governing the electrochemical storage performance of tunneled MnO2 cathodes, including (a) energetically favorable Li+ host sites, (ii) Li⁺ and electron transport capabilities, (iii) optimal intercalation pathways, crystal distortion, microstructural stability, and tunneled-to-layer phase transformation as a function of lithium content, and (iv) cell output voltage profile. Interestingly, we find that low K⁺ concentrations (y ≤ 1) yield partially cation-deficient tunnels in the MnO₂ cathode. Such unique tunnel structures in the cathode enable (a) low kinetic barriers for Li transport, (b)more » excellent thermodynamic stability of the tunneled structure even at a high Li⁺ loading (up to ~ 0.625 Li/Mn), and (c) good electronic conductivity facilitated by Jahn-Teller distortions; all of which are critical for achieving high capacity batteries with enhanced rate capability. Additionally, these results provide perspectives to design low-cost transition metal oxide cathodes for high-performance Li-ion batteries with excellent cycle life.« less

Authors:

Kempaiah, Ravindra  ^[1];

• Search DOE PAGES for author "Kempaiah, Ravindra"
• Search DOE PAGES for ORCID "0000-0001-8704-9058"

Chan, Henry  ^[2];

• Search DOE PAGES for author "Chan, Henry"
• Search DOE PAGES for ORCID "0000-0002-8198-7737"

Srinivasan, Srilok ^[3]; Sankaranarayanan, Subramanian KRS  ^[3];

• Search DOE PAGES for author "Sankaranarayanan, Subramanian KRS"
• Search DOE PAGES for ORCID "0000-0002-9708-396X"

Narayanan, Badri ^[4]; Subramanian, Arunkumar  ^[1]

• Search DOE PAGES for author "Subramanian, Arunkumar"
• Search DOE PAGES for ORCID "0000-0001-8779-391X"

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+ Show Author Affiliations

1. University of Illinois, Chicago, IL (United States)
2. University of Illinois, Chicago, IL (United States); Argonne National Laboratory (ANL), Lemont, IL (United States). Center for Nanoscale Materials
3. Argonne National Laboratory (ANL), Lemont, IL (United States). Center for Nanoscale Materials
4. University of Louisville, KY (United States)

Publication Date:

Fri Oct 15 00:00:00 EDT 2021

Research Org.:

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

Sponsoring Org.:

National Science Foundation (NSF); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office; USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1923077

Grant/Contract Number:  

AC02-06CH11357; EE0008866; 1661038; 1655496

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Energy Materials

Additional Journal Information:

Journal Volume: 4; Journal Issue: 11; Journal ID: ISSN 2574-0962

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

25 ENERGY STORAGE; alpha-manganese oxide; green electrode; lithium diffusion; lithium intercalation; lithium-ion battery; tunnel cathodes