Negative Charge Carbon Dots Manufacturing Electrostatic Shielding Layer for Stable Zinc Anode

Abstract

Alkaline zinc-based batteries (AZBs) can yield higher operating voltages due to a more negative electrode potential of zinc metal in alkaline electrolytes compared with neutral electrolytes, delivering high energy density in practical manufacturing applications. However, AZBs also exhibit more pronounced problems due to severe corrosion of the zinc anode by the strongly alkaline electrolyte environment. Combined with the reaction mechanism of alkaline zinc batteries, negatively charged carbon dots are innovatively used to construct a barrier with both physical and chemical effects. Zinc anode exposure to electrolyte is reduced by superior barrier, which assures transmission of zinc ions rather than zincate ions through electrostatic force balance, thus improving the distribution of the electric field for zinc ion deposition as well as avoiding accumulation of zincate ions at the interface. The number of harmful dendrite formation was found to be significantly suppressed by in situ optical microscopy. When coupled with silver oxide cathode for testing, the assembled silver-zinc battery results in a significant enhancement in its cyclic life. It is believed that this study will propel the development of zinc anode in alkaline batteries and provide new insights for their application.