Colloidal synthesis of monodisperse ultrathin LiFePO4 nanosheets for Li-ion battery cathodes

Lithium-ion conductivity is one of the critical factors in improving the rate capability of LiFePO4 in lithium-ion batteries. The one-dimensional diffusion pathway of lithium ions slows the charging/discharging rates in the olivine structure of LiFePO4. Herein, ultrathin LiFePO4 nanosheets were synthesized using surface-passivating ligands to address the rate capability issue. The thickness direction of the nanosheets is the [010] direction in which the lithium ions are inserted or extracted during cycling. The structural and morphological characterizations were performed via transmission electron microscopy and X-ray diffraction. A thickness of 7.5nm was obtained from the atomic force microscopy height profiles, which is in the scale of twelve unit cells of LiFePO4. Electrochemical performance test results revealed that the Li-ion batteries had superior rate capability during the charging/discharging process.

Automated summary

In this study, ultrathin LiFePO4 nanosheets were synthesized to address the issue of slow charging/discharging rates due to the one-dimensional diffusion pathway of lithium ions in the olivine structure of LiFePO4. Structural and morphological characterizations were performed using transmission electron microscopy and X-ray diffraction, while the thickness of the nanosheets was measured using atomic force microscopy height profiles. The electrochemical performance tests showed superior rate capability of the Li-ion batteries during the charging/discharging process.