Interfacial coordination effects for uniform and reversible zinc anode deposition

Abstract

The instability resulting from side reactions including zinc dendrites and hydrogen evolution observed at the interface between the anode and electrolyte has impeded the progress of aqueous zinc-ion batteries (AZIBs). In this study, 1,5-naphthalenedisulfonic acid (NA) is introduced to guide homogeneous and reversible deposition behavior of Zn2+ based on metal-coordination chemistry. Theoretical calculations combined with experiments demonstrate that the strong coordination effect between S and Zn results in the adsorption of a NA layer on the anode surface, suppressing side reactions while facilitating the uniform deposition of Zn2+. By and large, the inclusion of NA extends the cycling stability to nearly 3600 h at a current density of 0.5 mA cm−2 (0.5 mAh cm−2), and it enables durable cycling for 200 h even at a high current density of 20 mA cm−2 (10 mAh cm−2). The Zn||VNNC full battery can be cycled stably for 700 cycles at 5 A g−1 at a low N/P ratio (2.58). The consequence caters a new perspective on the coordination effect at the interface for zinc anodes to achieve high reversibility in AZIBs and ZICs.