Effect of Surface Structure on Electrochemical Properties in Li1.2Ni0.2Ti0.6O2 Cathode Material

The Li-excess disordered rock salt cathode material, Li1.2Ni0.2Ti0.6O2, 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 Li2TiO3 and LiNiO2 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.