Cationically Substituted Bi0.7Fe0.3OCI Nanosheets as Li Ion Battery Anodes

Cation substitutiob, of Bif(3+) with Fe3+ in BiOCl leads to the formation of tonically layered Bi0.7Fe0.3OCl nanosheets. The synthesis follows a hydrolysis route using bismuth(III) nitrate and iron(III) chloridejollowed by postannealing at 500 degrees C. Room temperature electrical conductivity improves from 6.11 X 10(-8) Sim for BiOCl tb 6.80 X 10(-7) S/m for Bi0.7Fe0.3OCl. Correspondingly, the activation energy for electriCal conduction reduces from 862 meV for pure BiOCI to 310 meV for Bi0.7Fe0.3OCl. These data suggest improved charge Mobility in Bi0.7Fe0.3OCl nanosheets. Density functional :theory calculations confirm this behavior by predicting a high density of states hear the Fermi level for Bi0.7Fe0.3OCl, The improvement in electrical conductivity is exploited in the electrochemical performance of Bi0.7Fe0.3OCl nanosheets. The insertion capacity of Li+ ions shows an increase of 2.5X, I from 215 mAh.g(-1) for undoped BiOCl to 542 mAh-g(-1) for Bi0.7Fe0.3OCl after 50 cycles at a current density of 50 mA g(-1). Thus, the direct substitution of Bi3+ sites with Fe3+ in BiOCI results in nanosheets of an tonically layered ternary semiconductor compound which is attractive for Li ion battery anode applications.