Structural, microstructural and electrochemical studies of TiO₂–Ag double layer coated NCM cathode for lithium-ion batteries

Lithium ion batteries as one of the most important energy storage equipments, have several challenges including capacity drop as number of cycles increases. Cathode particle coating is an effective approach in improvement of electrochemical performance of the batteries. In this study, TiO2–Ag coating was used to improve NCM cathode performance. The microstructure and crystal structure properties of coated NCMs were evaluated by the FE-SEM and XRD. Electrochemical behavior of the batteries was investigated by cycling performance analysis and EIS. TiO2 coating was deposited as a uniform layer and Ag coating was precipitated as dispersed nanoparticles. The results shows that using of TiO2–Ag coating can improve retention up to 75.9%. The FE-SEM and XRD studies of coated and uncoated NCMs after 100 cycles shows a higher crystalline and microstructural stability for coated NCMs. The TiO2 coated sample shows less increase in charge transfer resistance (62.4 %) than uncoated sample (232.9 %). The charge transfer resistance for TiO2–Ag coated sample decreased significantly.