Na-based layered transition metal oxides with an O3-type structure are considered as promising cathode materials for sodium-ion batteries (SIBs) due to their low cost, wide two-dimensional ion channels and high theoretical specific capacity. However, during storage, exposure to moisture and carbon dioxide in the air results in the formation of increased residual sodium compounds. This degradation exacerbates side reactions with the electrolyte and induces structural collapse, ultimately impairing their electrochemical performance. In this study, two titanium sources (e.g., itanium dioxide nanopowders and tetrabutyl titanate ethanol solution) were applied separately to develop two kinds of Na