The effects of supercritical carbon dioxide treatment on the morphology and electrochemical performance of LiFePO4 cathode materials

Abstract

As cathode materials, LiFePO₄ particles have been investigated after a supercritical carbon dioxide (scCO₂) treatment. We first produced LiFePO₄ through a hydrothermal method. Then, scCO₂ was introduced to change the morphology of the particles. Three effects have been found after the scCO₂ treatment; the breakup of the aggregated LiFePO₄ platelets into separate plates, the purification of LiFePO₄, and the formation of porous LiFePO₄. Electrochemical measurements showed that the performance of LiFePO₄ greatly improved after the scCO₂ treatment. Finally, a theoretical model was used to explain the mechanism of the morphology change.