Remarkable improvement in cell safety for Li[Ni0.5Co0.2Mn0.3]O2 coated with LiFePO4

Li[Ni0.5Co0.2Mn0.3]O2 has been synthesized by a co-precipitation method and the surface coated with nanosized LiFePO4 particles. Structural characterizations were performed by X-ray diffraction (XRD) studies and transmission electron microscopy (TEM) utilized to ensure the coating. A homemade aluminum pouch cell was assembled and studied at different C rates (0.5–20 C). At high current rates, the cell presented very stable discharge behavior. During the safety test, great enhancement of thermal and over-charge behavior was observed for LiFePO4-coated Li[Ni0.5Co0.2Mn0.3]O2 material.