Molybdenum-doped layered Li[Ni0.5+xMn0.5-2xMox]O-2 materials were synthesized by an ultrasonic spray pyrolysis method. Single phase of Li[Ni0.5+xMn0.5-2xMox]O-2 could be prepared in 0 less than or equal to x less than or equal to 0.05 region. Structural and electrochemical properties of the Li[Ni0.5+xMn0.5-2xMox]O-2 were characterized by means of X-ray diffraction, Rietveld refinements, and galvanostatic charge/discharge test. The discharge capacity increased linearly with the increase of molybdenum contents, x, and exhibited a high discharge capacity over 175 mAh/g between 2.8 and 4.4 V with a good capacity retention.