Highly efficient dendrite suppressor and corrosion inhibitor based on gelatin/Mn2+ Co-additives for aqueous rechargeable zinc-manganese dioxide battery

Abstract

Metallic Zn anode in aqueous rechargeable batteries generally suffers from corrosion and dendrite formation. In this work, these issues can be tackled by using synergistic effect of Mn2+ ions and gelatin as additives. The dendrite suppression was characterized by scanning electron microscopy and chronoamperometry examinations. It was found that the 0.2 M Mn2+ and 0.5 wt% gelatin in the electrolyte are beneficial to mitigate both dendrite growth and corrosion. Ex situ X-ray diffraction results suggested that the presence of Mn2+ ions during zinc depositing process changes the preferred zinc orientation from the (112) plane to (103) and (002) planes, which are not prone to zinc dendrite growth. The Zn//Zn symmetric cells revealed that the coexistence of Mn2+ ions and gelatin greatly increase the sand’s time (>500 h) of zinc dendrite formation. The assembled Zn//polyaniline/MnO2 battery using Mn2+/gelatin co-added electrolyte demonstrated good capacity retention of 80% after 1000 repeated cycles at 500 mAg−1. Furthermore, float charge current also obviously decreased from approximately 11.8 to 4.3 ~ 7.6 μA under 1.9 V constant voltage.