LiCoO2 cathode material is renovated and simultaneously separated from spent LiCoO2 electrodes containing LiCoO2, electron-conducting carbon, binder, Al current collector, and separator in a single synthetic step using hydrothermal method in a concentrated LiOH solution at 200°C without any scraping procedures. It is found that the renovated LiCoO2 phase crystallizes in the rhombohedral system with the space group R-3m. Although the obtained material has some electrochemically inactive impurities, the renovated LiCoO2 phase exhibits the first discharge capacity of 144.0mAh/g and the discharge capacity retention of 92.2% after 40 cycles.