Grain-dependent passivation of surfaces of polycrystalline zinc

Effects of texture on the electrochemical behaviors of single grains in polycrystalline zinc were investigated using a capillary-based micro-droplet cell. Pontiodynamic sweeps and capacity measurements were carried out in pH 9 borate buffer solution. The cyclic voltammograms and the capacity measurements on single grains with different crystallographic orientations in polycrystalline Zn showed a strong dependence of oxide growth on crystallographic grain orientation. The total charge consumed for oxide formation and the inverse capacity increased with an increase of surface packing density of grain, suggesting the oxide formation was greater on grains with higher surface packing density.