LiFePO4 Mesocrystals for Lithium-Ion Batteries



Olivine LiFePO4 is considered one of the most promising cathode materials for Li-ion batteries. A simple one-step, template-free, low-temperature solvothermal method is developed for the synthesis of urchinlike hierarchical mesocrystals of pristine LiFePO4 as well as carbon-coated LiFePO4 composites. Each urchinlike mesocrystal consists of LiFePO4 sheets self-assembled via a dipolar field in spheres during a solvothermal process under the influence of Cl anions. The obtained primary sheets of LiFePO4 are single crystalline in nature and can be coated in situ with an amorphous nitrogen-doped carbonaceous layer several nanometers in thickness. To increase the conductivity of the carbon coating, the materials are subjected to further temperature treatment (700 °C) under an inert atmosphere. The lithium storage performance of the pure LiFePO4 is compared with that of its carbon-coated counterparts.