Fluoride Doping Enhances Lithium Diffusivity in Layered Molybdenum Oxide

Fluoride doping MoO3 greatly increased the reversibility of lithium intercalation as seen in the dQ/dV plot, as well as the initial intercalation diffusivity, as seen from the GITT.

Scientific Achievement

By fluoride doping MoO3 to MoO2.8F0.2 the reversibility of lithium intercalation could be greatly increased and a sluggish intercalation step could be bypassed.

Significance and Impact

An earlier JCESR publication observed that Mg2+ intercalates more readily into MoO2.8F0.2 than MoO3. This work shows the initial intercalation step in MoO3 has a far lower diffusivity than the initial intercalation step of the fluoride doped compound. By showing a correlation between Li and Mg intercalation, we propose a method for screening Mg cathodes.

Research Details

  • Li+ intercalation studies were performed on both MoO3 and MoO2.8F0.2 and showed that fluoride doping greatly increased the reversibility and cycle life of the cathode.
  • The mobility of the intercalating species drops drastically at 75 mAh/g in the fluoride doped oxide upon lithium intercalation, corresponding to the Mg2+ capacity of 75 mAh/g in the same material.

DOI: 10.1021/acsaem.8b02141

Download this highlight

Latest Updates

See All