Essential Role of Spinel ZnFe₂O₄ Surfaces during Lithiation

Journal Article · 19 September 2018 · ACS Applied Materials and Interfaces

DOI: https://doi.org/10.1021/acsami.8b12869 · OSTI ID:1483560

Guo, Haoyue  ^[1]; Marschilok, Amy C.  ^[1]; Takeuchi, Kenneth J.  ^[1]; Takeuchi, Esther S.  ^[2]; Liu, Ping  ^[2]

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1. Stony Brook Univ., NY (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States)

Spinel zinc ferrite (ZnFe₂O₄) is a well-known anode material in lithium ion batteries (LIBs) due to its large theoretical capacity. However, the high potentials observed at the initial stage of lithiation observed cannot be captured using a model of Li⁺ intercalation into the stoichiometric ZnFe₂O₄ bulk. Here, using density functional theory (DFT) we report for the first time that theZnFe₂O₄ surfaces are responsible for the measured initial potentials. Among the three identified stable surfaces, ZnFeO₂-terminated ZnFe₂O₄(1 1 0), O-terminated ZnFe₂O₄(1 1 1) and Zn-terminated ZnFe₂O₄(1 1 1), both (1 1 1) surfaces display higher lithiation potentials than the (1 1 0) surface, and the estimated potentials based on Zn-terminated (1 1 1) fit well with the experimental observations, while using the models based on ZnFe₂O₄(1 1 0) and previously ZnFe₂O₄ bulk, the estimated potentials are much lower. In terms of Li⁺ diffusion, the Zn-terminated ZnFe₂O₄(1 1 1) surface is the most active, where the energetically favorable saturation of Li⁺ on the surface is able to facilitate the process. Our results provide a new strategy for the design of LIB materials, via controlling the particle shape and the associated surface characteristics thus enhancing the discharging performance.

• Research Organization: Energy Frontier Research Centers (EFRC) (United States). Center for Mesoscale Transport Properties (m2mt); Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1483560
• Report Number(s): BNL-209500-2018-JAAM
• Journal Information: ACS Applied Materials and Interfaces, Vol. 10, Issue 41; ISSN 1944-8244
• Publisher: American Chemical Society (ACS)Copyright Statement
• Country of Publication: United States
• Language: English