Through homogeneous precipitation method, uniform spherical alpha-Ni(OH)(2) particles were obtained at appreciate aging time in urea solution without any help of templates or dispersants. From SEM images, aging time exhibited great effects on the morphology of as-synthesized alpha-Ni(OH)(2). Also, long aging time helped to improve the electrochemical performances of alpha-Ni(OH)2. It was found that the proper aging time was 12 h. However, alpha-Ni(OH)(2) showed low charge/discharge capacities at high temperatures. Therefore, yttrium was added to improve the high-temperature electrochemical performances of alpha-Ni(OH)(2). The influences of doping ratios of Y on the morphologic and high-temperature electrochemical characteristics were investigated through XRD, SEM, TEM, constant current charge/discharge, and cyclic voltammetric measurements. The alpha-Ni(OH)2 samples with the addition of about 5.8 mol% Y showed a discharge capacity of 250 mAh/g at 0.2 C rate and 60 degrees C, much higher than that of alpha-Ni(OH)(2) without Y dopants (157 mAh/g). (c) 2006 Published by Elsevier Ltd.