In Situ Fabrication of Carbon-Encapsulated Fe7X8 (X = S, Se) for Enhanced Sodium Storage

Tiezhong Liu; Youpeng Li; Lingzhi Zhao; Fenghua Zheng; Yayun Guo; Yanxin Li; Qichang Pan; Yanzhen Liu; Junhua Hu; Chenghao Yang

doi:10.1021/acsami.9b00500

In Situ Fabrication of Carbon-Encapsulated Fe₇X₈ (X = S, Se) for Enhanced Sodium Storage

ACS Appl Mater Interfaces. 2019 May 29;11(21):19040-19047. doi: 10.1021/acsami.9b00500. Epub 2019 May 14.

Authors

Tiezhong Liu^{1

2}, Youpeng Li², Lingzhi Zhao¹, Fenghua Zheng², Yayun Guo¹, Yanxin Li¹, Qichang Pan², Yanzhen Liu², Junhua Hu³, Chenghao Yang²

Affiliations

¹ Guangdong Provincial Engineering Technology Research Center for Low Carbon and Advanced Energy Materials, Institute of Opto-Electronic Materials and Technology , South China Normal University , Guangzhou 510631 , P. R. China.
² Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy , South China University of Technology , Guangzhou 510006 , P. R. China.
³ School of Materials Science and Engineering , Zhengzhou University , Zhengzhou 450001 , P. R. China.

PMID: 31058492
DOI: 10.1021/acsami.9b00500

Abstract

Sodium-ion batteries (SIBs) have been regarded as a promising alternative to lithium-ion batteries due to the natural abundance of sodium in the earth's crust. In our work, fusiform Fe₇X₈@C (X = S, Se) composites were obtained via a one-step pyrolysis strategy applied to SIB anode materials. The formed carbon skeleton could prevent the Fe₇X₈ nanoparticles from agglomeration and stabilize the interface of Fe/Na₂X generated in the redox reactions. Fe₇X₈@C (X = S, Se) exhibits excellent reversible specific capacity (1005.3 mAh g^-1 under 0.2 A g^-1 for Fe₇S₈@C and 458.5 mAh g^-1 under 0.5 A g^-1 for Fe₇Se₈@C), outstanding rate performance (654.7 mAh g^-1 for Fe₇S₈@C and 392.9 mAh g^-1 for Fe₇Se₈@C going through 300 loops even under 2 A g^-1), and excellent cycling properties (795.8 mAh g^-1 after 50 loops under 0.2 A g^-1 for Fe7S₈@C and 399.9 mAh g^-1 going through 150 loops under 0.5 A g^-1 for Fe₇Se₈@C). The excellent electrochemical performance of Fe₇X₈@C composites makes them promising anode materials for SIBs.

Keywords: FeX@C (X = S, Se); MOFs; SIBs; anode; in situ.