Structure and Soft-Packed Cell Performance of Nano-Particle LiFePO₄ Prepared by Spray-Drying Method

Well-crystallized and nanosized LiFePO4/C composite have been successfully synthesized by spray-drying under N2 atmosphere. The morphology, physical and electrochemical properties of the LiFePO4/C were tested and analyzed. The charge transfer resistances (Rct) and chemical diffusion coefficients of lithium ions (DLi+) in LiFePO4/C was systematically tested by EIS. The results show that the lithium ions diffusion coefficients obtained from EIS is 1.58×10-14 cm2·s-1. The assembled soft-packed cell with LiFePO4/C show better rate capability and cycling stability. The average capacity retention of LiFePO4/C soft-packed cell decreases to 100%, 98.9%, 96.5%, 92.4%, and 90.3% when current rate increases to 0.3, 0.5, 1, 2, and 3C, respectively. The capacity retention after 80 cycles is retained at more than 99%.