Spray drying-assisted synthesis of LiFePO4/C composite microspheres with high performance for lithium-ion batteries

LiFePO4/C composite microspheres have been synthesized as lithium-ion battery cathode material with good high-rate capability and cycling stability. In the precursor, polyvinyl alcohol (PVA) gel was chosen as carbon source for its excellent film-forming properties in spray drying process. Both TEM and SEM results indicated that the carbon layers transformed from PVA gel films were well coated around LiFePO4 units in the composite microspheres. This unique LiFePO4/C composite microspheres exhibited excellent high-rate capability and cycling stability, with discharge capacities reaching up to 150 and 100 mAh g−1 at 0.1 C and 10 C current rates, respectively.

► A novel precursor “PVA gel” was adopted to realize uniform carbon coating in LiFePO4 microspheres.
► Uniform carbon coating in LiFePO4 microspheres result in high capacity and long-term cyclability at high current rate.
► A tap density as high as 1.2 g cm−3 were reached for the obtained LFP/C microspheres.
► The method is simple for large-scale production.