Electrochemical performance of SiO2-coated LiFePO4 cathode materials for lithium ion battery

The surface of LiFePO4/C particles was coated with SiO2 via a sol–gel method, and the electrochemical performance of SiO2-coated LiFePO4 cathode materials at room temperature and 55 °C was investigated. Compared with pristine LiFePO4, the structure of LiFePO4 with SiO2 coating had no change, the existence of SiO2 coating effectively enhanced the cycling capacity, reduced capacity fading at high temperature and alleviated the cell impedance. The SiO2 coating played a regulatory role for Li-ion inserting the lattice, by increasing the order of lithium ion intercalating the outer lattice of the particle. As a consequence, capacity retention improves significantly.

Research highlights▶ The surface of LiFePO4/C particles was coated with SiO2 via a sol-gel method. ▶ The existence of SiO2 coating effectively enhanced the discharge capacity, reduced capacity fading at high temperature and alleviated the cell impedance. ▶ The SiO2 coating played a regulatory role for Li-ion inserting the lattice, by increasing the order of lithium ion intercalating the outer lattice of the particle.