Correlation between the microstructure of carbon materials and their potassium ion storage performance

Xiuyi Lin, Jiaqiang Huang, Biao Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

39 Citations (Scopus)

Abstract

Alkali-metal ions storage in carbon materials is of great interests for developing high-performance anodes for batteries. While Li, Na ions storage has been extensively investigated, systematic studies on the correlation between K ions storage and carbon microstructure have rarely been conducted. The large radius of K ions leaves a legitimate question whether the charge storage sites for Li and Na ions are also active for K ions. Herein, electrospun carbon nanofibers are employed as model materials to explore the K-ion storage behaviors in carbon with representative microstructures. By combining in-situ characterization and theoretical calculations, three active sites have been unveiled, including (i) uptake of K-ion by defect sites; (ii) K ions adsorption on isolated graphene sheets in partially disordered carbon; (iii) K ions intercalation between graphene layers for carbon with a high degree of graphitization. A similar reversible capacity around 280 mAh/g is obtained for various carbon structures while their voltage profiles are highly disparate. Remarkably, it is found that non-graphitic carbon presents better rate capability and less temperature-dependence due to the faster ion diffusion. These findings offer new insights into the design of advanced carbon anode materials with tunable properties for K-ion batteries.

Original languageEnglish
Pages (from-to)138-146
Number of pages9
JournalCarbon
Volume143
DOIs
Publication statusPublished - Mar 2019

Keywords

  • Anodes
  • Carbon
  • In-situ characterization
  • K-ion batteries

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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