The effects of the coating characteristics of Y(OH)3 on the high-temperature performance of spherical Ni(OH)2 were studied. The coating was performed by chemical surface precipitation under different conditions, and the characterization of Y(OH)3-coating layer was evaluated accordingly. The electrochemical properties of three as-prepared samples with different coating surface were characterized and compared at different temperature. The results reveal that the sample with dense and porous surface retains the excellent performance at elevated temperatures, and the necessary coating amount is only 0.55at.%. The mechanism analysis suggests that the chemical nature and morphology of the coating layer plays an important role in oxygen evolution reaction (OER). The coating surface with dense and porous morphology, larger relative surface content and higher utilization ratio of yttrium is more effective on controlling OER and improving the high-temperature performance of Ni(OH)2 electrode for nickel–metal hydride (Ni/MH) batteries.