Unveiling Interstitial Anionic Electron-Driven Ultrahigh K-Ion Storage Capacity in a Novel Two-Dimensional Electride Exemplified by Sc3Si2

Yuanzheng Chen; Haifei Qin; Jun Zhou; Tong Yang; Bai Sun; Yuxiang Ni; Hongyan Wang; Simon A T Redfern; Maosheng Miao; Hai-Qing Lin; Yuan Ping Feng

doi:10.1021/acs.jpclett.2c01888

Unveiling Interstitial Anionic Electron-Driven Ultrahigh K-Ion Storage Capacity in a Novel Two-Dimensional Electride Exemplified by Sc₃Si₂

J Phys Chem Lett. 2022 Aug 18;13(32):7439-7447. doi: 10.1021/acs.jpclett.2c01888. Epub 2022 Aug 5.

Authors

Yuanzheng Chen^{1

2

3}, Haifei Qin², Jun Zhou^{3

4}, Tong Yang^{3

5}, Bai Sun², Yuxiang Ni², Hongyan Wang², Simon A T Redfern⁶, Maosheng Miao⁷, Hai-Qing Lin¹, Yuan Ping Feng³

Affiliations

¹ Beijing Computational Science Research Center, Haidian District, Beijing 100193, China.
² School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, China.
³ Department of Physics and Centre for Advanced Two-Dimensional Materials, National University of Singapore, Singapore 117551, Singapore.
⁴ Institute of Materials Research & Engineering, A*STAR (Agency for Science Technology and Research), 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore.
⁵ Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong 999077, P. R. China.
⁶ Asian School of the Environment and School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
⁷ Department of Chemistry and Biochemistry, California State University, Northridge, Northridge, California 91330, United States.

PMID: 35929958
DOI: 10.1021/acs.jpclett.2c01888

Abstract

Two-dimensional (2D) electrides, characterized by excess interstitial anionic electron (IAE) in a crystalline 2D material, offer promising opportunities for the development of electrode materials, in particular in rechargeable metal-ion batteries applications. Although a few such potential electride materials have been reported, they generally show low metal-ion storage capacity, and the effect of IAE on the ion storage performance remains elusive so far. Here we report a novel 2D electride, [Sc₃Si₂]¹⁺·1e^-, with fascinating IAE-driven high alkali metal-ion storage capacity. In particular, its K-ion specific capacity can reach up to 1497 mA h g^-1, higher than any previously reported 2D materials-based anodes in K-ion batteries (PIBs). The IAE in the [Sc₃Si₂]¹⁺·1e^- crystal accounts for such high capacity behavior, which can drift away and balance the charge on the metal-cation, playing a crucial role in stabilizing the metal-ion adsorption and enhancing multilayer-ions adsorption. This proposed IAE-driven storage mechanism provides an unprecedented avenue for the future design of high storage capacity electrode materials.