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

The Li-excess disordered rock salt cathode material, Li.sub.1.2Ni.sub.0.2Ti.sub.0.6O.sub.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.sub.2TiO.sub.3 and LiNiO.sub.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.sup.-1 at 20 mA g.sup.-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.