Nanostructured Iron Fluoride Derived from Fe-Based Metal-Organic Framework for Lithium Ion Battery Cathodes

Qiuxia Cheng; Yingying Pan; Yueying Chen; Akif Zeb; Xiaoming Lin; Zhongzhi Yuan; Jincheng Liu

doi:10.1021/acs.inorgchem.0c01783

Nanostructured Iron Fluoride Derived from Fe-Based Metal-Organic Framework for Lithium Ion Battery Cathodes

Inorg Chem. 2020 Sep 8;59(17):12700-12710. doi: 10.1021/acs.inorgchem.0c01783. Epub 2020 Aug 10.

Authors

Qiuxia Cheng¹, Yingying Pan¹, Yueying Chen¹, Akif Zeb¹, Xiaoming Lin^{1

2}, Zhongzhi Yuan¹, Jincheng Liu³

Affiliations

¹ Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, P. R. China.
² School of Environment and Energy, South China University of Technology, Guangzhou 510006, Guangdong, P. R. China.
³ EVE Energy Co. Ltd., Huizhou 516006, Guangdong, P. R. China.

PMID: 32806004
DOI: 10.1021/acs.inorgchem.0c01783

Abstract

A comprehensive strategy for the morphological control of octahedral and spindle Fe-based metal-organic frameworks (Fe-MOFs) via microwave-assisted adjustment is proposed in this research. Afterward, in situ copyrolysis under N₂ atmosphere contributes to the fabrication of two shape-maintained FeF₃·0.33H₂O nanostructures (named O-FeF₃·0.33H₂O and S-FeF₃·0.33H₂O, respectively) with confined hierarchical porosity and graphitized carbon skeleton. The lithium storage performances for the MOF-derived octahedral O-FeF₃·0.33H₂O and spindle S-FeF₃·0.33H₂O composites are investigated, and the prospective lithium storage mechanism is discussed. As a result, the main product of the porous O-FeF₃·0.33H₂O structure is found to be a promising cathode material for lithium ion batteries owing to its advantageous electrochemical capability. Even after being cycled over 1000 times at 2 C (1 C = 237 mAh g^-1), the capacity attenuation rate of the as-prepared O-FeF₃·0.33H₂O electrode is as low as 0.039% per cycle. The combination of proper octahedral morphology and highly graphitized carbon modification can not only enhance the conductivity of the cathode but also promote the diffusion of Li⁺ effectively. The remarkable performance of octahedral O-FeF₃·0.33H₂O can be confirmed by the Li-ion diffusion coefficient (D_Li⁺) calculation analysis and kinetics analysis of lithium storage behavior.