Hybrid organic/inorganic coating for protecting zinc electrode in a zinc-air battery

The effectiveness of a hybrid organic/inorganic protective coating on the corrosion behavior of zinc as anode in a Zn-air battery with NaCl as electrolyte was investigated. The use of a neutral electrolyte is useful for limiting carbonation and the formation of dendrites, typical of alkaline solutions. The behavior of the coated and uncoated zinc electrode has been studied with various electrochemical techniques (linear sweep voltammetry, EIS and potentiostatic measurements and galvanostatic discharge tests). Chemical and morphological investigations were carried out by Raman spectroscopy and AFM. The electrochemical results highlighted the beneficial effects of the coating which also led to a higher discharge capacity. The spectroscopic information together with the AFM images and the related roughness measurements demonstrated the lower susceptibility to corrosion of the coated zinc sample. The presence of the coating, which slows down passivation without blocking corrosion, is advantageosu for recharging the zinc electrode of the zinc-air battery.