Mn-Doped Fe1- xMn xF3·0.33H2O/C Cathodes for Li-Ion Batteries: First-Principles Calculations and Experimental Study

Jing Ding; Xiangyang Zhou; Hui Wang; Juan Yang; Yuning Gao; Jingjing Tang

doi:10.1021/acsami.8b17069

Mn-Doped Fe_{1- x}Mn _xF₃·0.33H₂O/C Cathodes for Li-Ion Batteries: First-Principles Calculations and Experimental Study

ACS Appl Mater Interfaces. 2019 Jan 30;11(4):3852-3860. doi: 10.1021/acsami.8b17069. Epub 2019 Jan 15.

Authors

Jing Ding¹, Xiangyang Zhou¹, Hui Wang¹, Juan Yang¹, Yuning Gao¹, Jingjing Tang¹

Affiliation

¹ School of Metallurgy and Environment , Central South University , Changsha 410083 , China.

PMID: 30601651
DOI: 10.1021/acsami.8b17069

Abstract

Increasing attention has been paid on iron fluoride as an alternative cathode material for Li-ion batteries (LIBs) owing to its high energy density and low cost. However, the poor electric conductivity and low diffusivity for Li-ions set great challenges for iron fluoride to be used in practical LIBs. Here, we employ first-principles calculations to probe the influence of Mn-doping on the crystal structure and electronic structure of FeF₃·0.33H₂O. The calculated results suggest that Mn-doping can enlarge the hexagonal cavity and reduce the band gap of FeF₃·0.33H₂O as well as improve its intrinsic conductivity. Furthermore, Fe_{1- x}Mn _xF₃·0.33H₂O/C ( x = 0, 0.06, 0.08, and 0.10) nanocomposites were successfully fabricated by a hydrothermal method and ball-milling. Owing to the Mn-doping effect combined with highly conductive acetylene black (AB) modification, the typical Fe_0.92Mn_0.08F₃·0.33H₂O/C composite exhibits a high discharge capacity of 180 mA h g^-1 at 50 mA g^-1 after 100 cycles and delivers excellent cycling stability as well as good rate capability.

Keywords: Fe1−xMnxF3·0.33H2O/C nanocomposites; Li-ion batteries; Mn-doping; cathode material; first-principles calculations.