Electrode/Electrolyte Interfacial Chemistry Modulated by Chelating Effect for High-Performance Zinc Anode

Abstract

Although Zn metal has been regarded as the most promising anode for aqueous batteries, its practical application is still restricted by side reactions and dendrite growth. Herein, an in-situ solid electrolyte interphase (SEI) film formed on the interface of electrode/electrolyte during the plating/stripping of zinc anodes by introducing trace amounts of multidentate ligand sodium diethyldithiocarbamate (DDTC) additive into 1 m ZnSO4. The synergistic effect of in-situ solid electrolyte interphase forming and chelate effect endows Zn2+ with uniform and rapid interface-diffusion kinetics against dendrite growth and surface side reactions. As a result, the Zn anode in 1 m ZnSO4 + DDTC electrolytes displays an ultra-high coulombic efficiency of 99.5% and cycling stability (more than 2000 h), especially at high current density (more than 600 cycles at 40 mA cm−2). Moreover, the Zn//MnO2 full cells in the ZnSO4 + DDTC electrolyte exhibit outstanding cyclic stability (with 98.6% capacity retention after 2000 cycles at 10 C). This electrode/electrolyte interfacial chemistry modulated strategy provides new insight into enhancing zinc anode stability for high-performance aqueous zinc batteries.