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

As cathode materials, LiFePO4 particles have been investigated after a supercritical carbon dioxide (scCO(2)) treatment. We first produced LiFePO4 through a hydrothermal method. Then, scCO(2) was introduced to change the morphology of the particles. Three effects have been found after the scCO(2) 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 scCO(2) treatment. Finally, a theoretical model was used to explain the mechanism of the morphology change.