Doping and thermal treatment strategies to construct layered oxide: an excellent air-stable cathode for sodium-ion batteries

The application of Sodium ion battery layer oxide is limited by their structural and air instability. The specific discharge capacity of NaNi 0.47 Cu 0.03 Mn 0.5 O 2 (NNMC) is 75.9 mA h g −1 after 200 cycles at 0.5 C, and the material has a specific capacity of 94.9 mA h g −1 after 10 days of exposure at 0.1 C. Due to the strong bond energy of Ti O, the introduction of Ti 4+ improves the structural and the air stability of NNMC layered oxide. The electrochemical performances of the doped sample have been improved. Thermal treatment strategies can stabilize the reconstruction of structures and lattices, making the material surface more regular and the particle size more uniform. In order to enable the exposed materials to be reused. The exposed materials effectively restore the discharge specific capacity and rate performance, and enhance the air stability of the materials by thermal treatment. The introduction of Ti 4+ and thermal treatment provide an instruction for the study and application of layered oxides in sodium-ion batteries. • Ti doping improves the structural and electrochemical performance of layered oxide. • Thermal treatment is applied to enhance the air stability of cathode materials. • The dual strategies provide a research idea for the design of SIBS cathode materials.