Suppressing by-product via stratified adsorption effect to assist highly reversible zinc anode in aqueous electrolyte

Abstract

The Sc 2 O 3 -coated Zn anode with a stratified adsorption effect can greatly boost the Zn 2+ /Zn plating/stripping CEs via radically suppressing the formation of irreversible Zn 4 (OH) 6 SO 4 ·H 2 O by-product in aqueous electrolyte. • A new kind of artificial Sc 2 O 3 -coated Zn anode with a stratified adsorption effect was demonstrated. • This unique structure and effect greatly alleviate HER reaction and suppress generation of Zn 4 (OH) 6 SO 4 ·H 2 O by-product. • The Sc 2 O 3 -coated Zn anode exhibits excellent performance when matched with manganese-based and vanadium-based cathodes. The development of promising zinc anodes mainly suffers from their low plating/stripping coulombic efficiencies when using aqueous electrolyte, which are mainly associated with the interfacial formation of irreversible by-products. It is urgent to develop technologies that can solve this issue fundamentally. Herein, we report an artificial Sc 2 O 3 protective film to construct a new class of interface for Zn anode. The density functional theory simulation and experimental results have proven that the interfacial side reaction was inhibited via a stratified adsorption effect between this artificial layer and Zn anode. Benefiting from this novel structure, the Sc 2 O 3 -coated Zn anode can run for more than 100 cycles without short circuit and exhibit low voltage hysteresis, and the coulombic efficiency increases by 1.2%. Importantly, it shows a good application prospect when matched with two of popular manganese-based and vanadium-based cathodes. The excellent electrochemical performance of the Sc 2 O 3 -coated Zn anode highlights the importance of rational design of anode materials and demonstrates a good way for developing high-performance Zn anodes with long lifespan and high efficiency.