Titanium oxide (TiO_x) coating was treated on a surface of A LiNi_aCo_bAl_1-a-bO₂ (a > 0.85) cathode material, which exhibited high capacity of 200 mAhg^-1 and however, the charge/discharge capacity with pristine LiNi_aCo_bAl_1-a-bO₂ degraded seriously after contacting with water. The formation of TiO_x layer on the cathode material surface was characterized with field-emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The TiO_x-coated LiNi_aCo_bAl_1-a-bO₂ cathode material did not form bubbles in the coating process when a water-based slurry was prepared with TiO_x-coated LiNi_aCo_bAl_1-a-bO₂ particles and a water-based hybrid polymer binder, and then the slurry was coated on a aluminum current collector. Therefore, the cathode electrode fabricated with TiO_x-coated LiNi_aCo_bAl_1-a-bO₂ exhibited comparable cycle and rate performance with the cathode which was composed of pristine LiNi_aCo_bAl_1-a-bO₂ particle and organic solvent-based PVdF binder even after it was exposed in the water-based slurry for 7 days.