Sodium-Ion Intercalation Mechanism in MXene Nanosheets

Satoshi Kajiyama, Lucie Szabova, Keitaro Sodeyama, Hiroki Iinuma, Ryohei Morita, Kazuma Gotoh, Yoshitaka Tateyama, Masashi Okubo, Atsuo Yamada

Research output: Contribution to journalArticle

171 Citations (Scopus)

Abstract

MXene, a family of layered compounds consisting of nanosheets, is emerging as an electrode material for various electrochemical energy storage devices including supercapacitors, lithium-ion batteries, and sodium-ion batteries. However, the mechanism of its electrochemical reaction is not yet fully understood. Herein, using solid-state 23Na magic angle spinning NMR and density functional theory calculation, we reveal that MXene Ti3C2Tx in a nonaqueous Na+ electrolyte exhibits reversible Na+ intercalation/deintercalation into the interlayer space. Detailed analyses demonstrate that Ti3C2Tx undergoes expansion of the interlayer distance during the first sodiation, whereby desolvated Na+ is intercalated/deintercalated reversibly. The interlayer distance is maintained during the whole sodiation/desodiation process due to the pillaring effect of trapped Na+ and the swelling effect of penetrated solvent molecules between the Ti3C2Tx sheets. Since Na+ intercalation/deintercalation during the electrochemical reaction is not accompanied by any substantial structural change, Ti3C2Tx shows good capacity retention over 100 cycles as well as excellent rate capability.

Original languageEnglish
Pages (from-to)3334-3341
Number of pages8
JournalACS Nano
Volume10
Issue number3
DOIs
Publication statusPublished - Mar 22 2016

Keywords

  • Na NMR
  • intercalation
  • MXene
  • negative electrode
  • sodium-ion battery

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

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  • Cite this

    Kajiyama, S., Szabova, L., Sodeyama, K., Iinuma, H., Morita, R., Gotoh, K., Tateyama, Y., Okubo, M., & Yamada, A. (2016). Sodium-Ion Intercalation Mechanism in MXene Nanosheets. ACS Nano, 10(3), 3334-3341. https://doi.org/10.1021/acsnano.5b06958