Thermal stability of LiFePO4/C-LiMn2O4 blended cathode materials

Safety is important to lithium ion battery materials. The thermal stability of LiFePO4/C-LiMn2O4 blended cathode materials is characterized by using TG, XRD, and SEM etc. The results show that LiFePO4/C-LiMn2O4 possesses a worse thermal stability than pure spinel LiMn2O4 and pure olivine LiFePO4/C. When LiFePO4/C-LiMn2O4 blended cathode materials are sintered at 500°C under Ar atmosphere, the sintered cathode materials emit O2, and appear impurity phases (Li3PO4, Fe2O3, Mn3O4). It is deduced that some chemical reactions take place between different materials, which leads to a worse discharge specific capacity. LiFePO4/C-LiMn2O4 blended cathode materials, therefore, need to be managed and controlled strictly for the sake of thermal stability and safety.