Inhibition of zinc dendrite growth in zinc-air batteries by alloying the anode with Ce and Yb

Abstract

Zinc-air batteries have garnered significant attention owing to their high energy density and substantial anode active substance storage. Despite their potential advantages, the application of zinc-air batteries has been hindered in various domains by rapid performance degradation and reduced service life caused by zinc dendrite growth during cycling. This study presents a method of alloying zinc anodes with rare earth metals, such as Ce and Yb, as well as alkaline earth metal Mg to mitigate the growth of zinc dendrites. This is achieved by altering the anisotropy modulus and intensity at the interface energy of the zinc anode. This approach was verified using a COMSOL phase-field model based on an experimental study. The findings demonstrate that the optimal suppression of zinc dendrite growth was achieved with the anisotropy modulus of 6 and the inhibition efficiency is 35%. Moreover, the degree of anisotropic intensity exhibited by the interfacial energy was inversely proportional to the inhibition of zinc dendrite growth. The most effective approach to inhibit dendrite growth involved using a zinc anode composition of 98% Zn–2% Mg and 93.5% Zn–6.5% Yb. The addition of Ce into the zinc anode was found to increase the anisotropy modulus of the anode interface energy, changing the direction and decreasing the height of zinc dendrite growth. Similarly, the addition of Yb to the zinc anode decreased the anisotropic intensity of the interface energy, thereby impeding the growth of the main stem dendrite.