Novel Iron Bismuth Oxychloride Nanosheets for Lithium Ion Batteries

Iron Bismuth Oxychloride nanosheets were successfully synthesized by facile hydrolysis method. The X-ray photoelectron spectroscopy (XPS) shows composition was uniformly controlled as Fe 0.3 Bi 0.7 OCl. UV-Vis spectra and cyclic voltammetry (CV) results show the band gap of nanosheets correspondingly decreased from 3.4 eV for BiOCl to 2.08 eV for Fe 0.3 Bi 0.7 OCl due to raising of the valence band edge. Activation energy for electrical conductivity reduced from 862 meV to 796 meV for BiOCl and Fe 0.3 Bi 0.7 OCl, respectively. Density functional theory calculations predict changes to the valence band and decrease in the Fermi level toward the valence band edge for the Fe 0.3 Bi 0.7 OCl nanosheets - in accordance with experimental data. Correspondingly the Li ion capacities increased from 215 mAh/g for BiOCl to 542 mAh/g for Fe 0.3 Bi 0.7 OCl after 50 cycles at the current density of 100 mA/g.