Lithium-rich cathode material was synthesized by a sol-gel method, and the product Li[Li0.2Ni0.15Mn0.55Co0.1-xCrx]O2-yCly was calcined at 900 oC for 12 h. X-ray diffraction (XRD) spectroscopy tests present the α-NaFeO2 layered structure of the material. Scanning electron microscopy (SEM) indicates that its particle size is uniform and can reach nano-range; electrochemical testing shows that for the material with Cl- and Cr3+ co-doping in 2~4.8 V voltage and 0.1 C rate, its initial discharge specific capacity reaches 239.8 mAh·g-1 and coulombic efficiency is 81.2% at 20 oC; while at 55 oC, in the same conditions, the initial discharge specific capacity and the first coulombic efficiency are 308.3 mAh·g-1 and 92.7%, respectively. After 40 cycles, at the rate of 1 C, the specific capacities retain 173.5 mAh·g-1 at 20 oC and 207.7 mAh·g-1 at 55 oC.