December 1 - 6, 2024
Boston, Massachusetts
Symposium Supporters
2024 MRS Fall Meeting & Exhibit
EN08.12.04

Accessing Mg-Ion Storage in V2PS10 via Combined Cationic-Anionic Redox with Selective Bond Cleavage

When and Where

Dec 6, 2024
10:15am - 10:30am
Hynes, Level 3, Ballroom C

Presenter(s)

Co-Author(s)

Matthew Wright1,2,Todd Surta2,Jae Evans2,Jungwoo Lim2,Hongil Jo2,Cara Hawkins2,Mounib Bahri2,Luke Daniels2,Ruiyong Chen2,Marco Zanella2,Giannantonio Cibin3,Alan Chadwick4,Matthew Dyer2,Nigel Browning2,John Claridge2,Laurence Hardwick2,Matthew Rosseinky2

University of California, Santa Barbara1,University of Liverpool2,Diamond Light Source3,University of Kent4

Abstract

Matthew Wright1,2,Todd Surta2,Jae Evans2,Jungwoo Lim2,Hongil Jo2,Cara Hawkins2,Mounib Bahri2,Luke Daniels2,Ruiyong Chen2,Marco Zanella2,Giannantonio Cibin3,Alan Chadwick4,Matthew Dyer2,Nigel Browning2,John Claridge2,Laurence Hardwick2,Matthew Rosseinky2

University of California, Santa Barbara1,University of Liverpool2,Diamond Light Source3,University of Kent4
Magnesium batteries attract interest as alternative energy-storage devices because of elemental abundance and potential for high energy density. Development is limited by the absence of suitable cathodes, associated with poor diffusion kinetics resulting from strong interactions between Mg<sup>2+</sup> and the host structure. V<sub>2</sub>PS<sub>10</sub> is reported as a positive electrode material for rechargeable magnesium batteries with fast insertion kinetics. Cyclable capacity of 100 mAh g<sup>-1</sup> is achieved with Mg<sup>2+</sup> diffusion of 7×10<sup>-11</sup> - 4×10<sup>-14</sup> cm<sup>2</sup> s<sup>-1</sup>. The fast insertion mechanism results from combined cationic redox on the V site and anionic redox on the (S<sub>2</sub>)<sup>2</sup><sup>-</sup> site; enabled by reversible cleavage of S–S bonds, identified by X-ray photoelectron and X-ray absorption spectroscopy. Detailed structural characterisation with maximum entropy method analysis, supported by density functional theory and projected density of states analysis, reveals that the sulfur species involved in anion redox are not connected to the transition metal centres, spatially separating the two redox processes. This facilitates fast and reversible Mg insertion in which the nature of the redox process depends on the cation insertion site, creating a synergy between the occupancy of specific Mg sites and the location of the electrons transferred.

Keywords

intercalation | x-ray diffraction (XRD)

Symposium Organizers

Kelsey Hatzell, Vanderbilt University
Ying Shirley Meng, The University of Chicago
Daniel Steingart, Columbia University
Kang Xu, SES AI Corp

Session Chairs

Rafael Gomez-Bombarelli
Kang Xu

In this Session