Effect of surface structure on electrochemical properties in Li 1.2 Ni 0.2 Ti 0.6 O 2 cathode material

The Li-excess disordered rock salt cathode material, Li 1.2 Ni 0.2 Ti 0.6 O 2 , was synthesized via the sol–gel method to investigate the impact of different sintering temperatures on its structure, morphology, and electrochemical performance. X-ray diffraction (XRD) analysis revealed a cubic rock salt structure for the material. Raman spectroscopy indicated the presence of short-range-ordered domains of Li 2 TiO 3 and LiNiO 2 in the samples. The XPS results confirmed the existence of an oxygen vacancy structure on the sample’s surface. Morphological observations demonstrated that micron-scale secondary particles agglomerated with nanoscale primary particles, resulting in a nano-microstructure formation. Electrochemical testing conducted at room temperature within a voltage range of 1.5 ~ 4.8 V showed that the sample sintered at 600 °C exhibited the highest specific discharge capacity of approximately 304.4 mAh g −1 at 20 mA g −1 . The influence of surface structure on electrochemical properties in disordered rock salt cathode materials is elucidated through interactions between small primary particles and surface oxygen vacancies.