Highly reversible zinc anode enabled by a trace-amount additive with pH buffering capability

Abstract

Both high reversibility and cycle stability for zinc anode are desirable for practical applications. However, it is a challenge to obtain both of them due to severe hydrogen evolution, corrosion and pH fluctuation. Here, a trace-amount additive (0.1wt.%), ammonium succinate, is proposed to effectively suppress above issues. The additive with high zinc absorbability not only participates in Zn2+ solvation shell, reducing H2O activity in solvation shell, but also forms adsorption layer to inhibit corrosion and regulate ion flux for uniform deposition. More importantly, strong pH buffering ability enabled by NH4+ endows batteries with high cycle stability. Therefore, unprecedent high average coulombic efficiency of 99.91% at 1mA cm−2 was obtained, and symmetrical cell can stably cycle with high cumulative capacity 6150 mAh cm−2 at 10 mA cm−2, demonstrating the feasibility for both high reversibility and cycle stability for zinc anode.