Approaching theoretical specific capacity of iron-rich lithium iron silicate using graphene-incorporation and fluorine-doping

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Tianwei Liu
  • Yadong Liu
  • Yikang Yu
  • Chengjun Sun
  • Yuzi Liu
  • Jiayi Xu
  • Cong Liu
  • Zhenzhen Yang
  • Wenquan Lu
  • Paulo Ferreira
  • Zisheng Chao
  • Jian Xie

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)4006-4014
Journal / PublicationJournal of Materials Chemistry A
Volume10
Issue number8
Online published17 Jan 2022
Publication statusPublished - 28 Feb 2022

Abstract

Lithium iron silicate, Li2FeSiO4, is a promising cathode material for lithium ion batteries due to its high theoretical specific capacity, earth abundance, low cost, and environmental friendliness. The challenges of Li2FeSiO4 as a practical cathode material are (1) the low electronic and ionic conductivity and (2) the low discharge voltage. The approach of incorporating graphene sheets into the nanostructure of Li2FeSiO4 is used for dealing with the low conductivities while fluorine doping is intended to increase the discharge voltage. The fluorine-doped and graphene-incorporated iron-rich lithium iron silicate F-LFSO/G nanomaterials were successfully synthesized using a facile/efficient hydrothermal method with excellent performance, 328.43 mA h g-1 at 0.1C rate, approaching their theoretical specific capacity, 99% of 331 mA h g-1. This clearly reveals that the reversible (de)lithiation of 2 Li+ ions per F-LFSO has been realized as a result of these approaches. The (de)lithiation process has been studied using in operando high energy synchrotron X-ray absorption near edge spectroscopy and X-ray photoelectron spectroscopy aided by theoretical modeling, which reveals that F doping deeply changes the O electron configuration in F-LFSO, and consequently makes the Li+ ion transfer easier, while the reversible redox of oxygen can be utilized to achieve high specific capacity.

Research Area(s)

  • ELECTROCHEMICAL PERFORMANCE, STRUCTURAL STABILITY, CATHODE MATERIAL, LI2FESIO4, MECHANISM, DESIGN, MN, FE

Citation Format(s)

Approaching theoretical specific capacity of iron-rich lithium iron silicate using graphene-incorporation and fluorine-doping. / Liu, Tianwei; Liu, Yadong; Yu, Yikang; Ren, Yang; Sun, Chengjun; Liu, Yuzi; Xu, Jiayi; Liu, Cong; Yang, Zhenzhen; Lu, Wenquan; Ferreira, Paulo; Chao, Zisheng; Xie, Jian.

In: Journal of Materials Chemistry A, Vol. 10, No. 8, 28.02.2022, p. 4006-4014.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review