Metal-Metal Bonding as an Electrode Design Principle in the Low-Strain Cluster Compound LiScMo3O8

Kira E Wyckoff; Jonas L Kaufman; Sun Woong Baek; Christian Dolle; Joshua J Zak; Jadon Bienz; Linus Kautzsch; Rebecca C Vincent; Arava Zohar; Kimberly A See; Yolita M Eggeler; Laurent Pilon; Anton Van der Ven; Ram Seshadri

doi:10.1021/jacs.1c12070

Metal-Metal Bonding as an Electrode Design Principle in the Low-Strain Cluster Compound LiScMo₃O₈

J Am Chem Soc. 2022 Apr 6;144(13):5841-5854. doi: 10.1021/jacs.1c12070. Epub 2022 Mar 25.

Authors

Affiliations

¹ Materials Department and Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, California 93106, United States.
² Mechanical and Aerospace Engineering Department, Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, California 90095, United States.
³ Laboratory for Electron Microscopy, Microscopy of Nanoscale Structures and Mechanisms, Karlsruhe Institute of Technology, Engesserstraße 7, 76131 Karlsruhe, Germany.
⁴ Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
⁵ Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States.
⁶ California NanoSystems Institute and Institute of the Environment and Sustainability, University of California Los Angeles, Los Angeles, California 90095, United States.

PMID: 35333056
DOI: 10.1021/jacs.1c12070

Abstract

Electrode materials for Li⁺-ion batteries require optimization along several disparate axes related to cost, performance, and sustainability. One of the important performance axes is the ability to retain structural integrity though cycles of charge/discharge. Metal-metal bonding is a distinct feature of some refractory metal oxides that has been largely underutilized in electrochemical energy storage, but that could potentially impact structural integrity. Here LiScMo₃O₈, a compound containing triangular clusters of metal-metal bonded Mo atoms, is studied as a potential anode material in Li⁺-ion batteries. Electrons inserted though lithiation are localized across rigid Mo₃ triangles (rather than on individual metal ions), resulting in minimal structural change as suggested by operando diffraction. The unusual chemical bonding allows this compound to be cycled with Mo atoms below a formally +4 valence state, resulting in an acceptable voltage regime that is appropriate for an anode material. Several characterization methods including potentiometric entropy measurements indicate two-phase regions, which are attributed through extensive first-principles modeling to Li⁺ ordering. This study of LiScMo₃O₈ provides valuable insights for design principles for structural motifs that stably and reversibly permit Li⁺ (de)insertion.