Morphology study of zinc anode prepared by electroplating method for rechargeable Zn-MnO₂ battery

Zinc electrodes prepared by electrodepositing zinc on a copper plate in ZnSO₄ electrolyte were studied to determine the most suitable condition of zinc anode preparation for high performance Zn-MnO₂ battery. Deposition of zinc on substrate material was confirmed using X-ray diffraction (XRD) measurement. Morphological characterization of zinc anode was performed by scanning electron microscopy (SEM). It was observed that concentration of electrolyte and electrical current density influenced the morphology of zinc electrode. At 1 M ZnSO₄ and current density values of 0.06-0.1 A/cm², it was found that the morphological structure of zinc electrode was orderly arranged in a layer-by-layer structure. This indicated that the current density played an important role on deposition morphology and even on the crystal structure. Performance of electrodes was tested by a battery analyzer for 100 cycles. The results of the tests showed that the electrode with the layer-by-layer morphology yielded a high efficiency of up to 99.97% which was higher and more stable than those of the electrodes with disordered and scattered morphology. The layer-by-layer morphology is therefore a key factor for improving the performance of Zn-MnO₂ cell.