Construction of ultrathin N-doped carbon shell on LiFePO4 spheres as enhanced cathode for lithium ion batteries

Abstract Developing advanced cathode is playing a crucial role in the advancement of lithium ion batteries (LIBs). In this work, we report a novel one-step spray drying method for fabrication of N-doped carbon (N-C) coated LiFePO 4 spheres forming LiFePO 4 /N-C spheres composite. Thin N-C layer of about 5 nm was coating on the surface of LiFePO 4 spheres. The electrochemical properties of LiFePO 4 /N-C spheres composite have been thoroughly studied as cathode of LIBs. The LiFePO 4 /N-C spheres composite delivers discharge capacities of 160, 143 and 115 mAh g −1 at 1 C, 5 C and 20 C, respectively, much better than unmodified LiFePO 4 cathode. A high discharge capacity of 159 mAh g −1 is preserved with 99% capacity retention after 1000 cycles at 1 C. The enhanced performance is due to the introduction of N-C shell with improved electrical conductivity and structural stability.