Nickel hydroxides doped with different yttrium contents were prepared by a supersonic co-precipitation method. Their particle size distribution, crystal structures and electrochemical performance were characterized. The XRD results show the co-existence of α and β phase in the nickel hydroxides. The laser particle size measurement indicates that all the samples are of nanoparticles, which are distributed uniformly with average size of 50-80 nm. Complex electrodes were prepared by mixing 8wt% nickel hydroxides with commercial micro-sized spherical nickel. The cyclic voltammetry results show that the reversibility and charge efficiency of the electrodes are increased initially and then decreased with the increase of Y content. The best reversibility and charge efficiency is observed in the electrodes with 1.17wt% Y. The discharge capacity reaches 370 mAh/g at 0.1 C and 358 mAh/g at 0.5 C for the 1.17wt% Y-doped electrodes, higher than the theoretical value of pure β-Ni(OH)2. The data is 48%-60% higher than the capacity of market Ni(OH)2 battery (230-250 mAh/g). F Furthermore, low charge potential and high discharge plateau are also observed. inally, the samples prepared under supersonic were compared with that without supersonic