Realizing highly stable zinc-ion batteries via electrolyte engineering with adsorbed molecular protective layer

Abstract

Uncontrolled dendrites, corrosion and passivation of Zn metal seriously limit the development of Zn-ion batteries (ZIBs). Electrolyte engineering with various additives is a promising approach due to its high operability and significant effects. Herein, we report a low-cost and high-effective cysteamine (CS) as the additive to achieve dendrite-free ZIBs. Dendrite-free ZIBs with CS as the organic additive can prevent direct contact of Zn with water through a dynamic adsorption layer and desolvation of [Zn(H2O)6]2+. The optimized electrolyte also shows advantages in re-regulating the Zn ion fluxes and holding the steady hydrophobic interface during the electrochemical process to alleviate water decomposition and anode corrosion during cycling. CS employed as the additive enables stable Zn plating and stripping over 1360 h at the current density of 1 mA cm−2 and the capacity of 1 mAh cm−2. The Zn/diquinoxalino [2,3-a:2′,3′-c] phenazine (HATN) and Zn/Mn-doped V2O5 (MVO) full cells with CS as the additive exhibits ultra-high Coulombic efficiency (CE, 100 ± 0.3%) as well as long cycling performance at the current density of 1 A g−1. This work will provide a novel experimental approach in understanding the dendrite-suppression mechanism and pave a way to construct electrolyte engineering for ZIBs.