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

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 electro-chemical 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.

Automated summary

This study presents a low-cost and effective approach to achieve dendrite-free zinc-ion batteries (ZIBs) using cysteamine (CS) as an additive. The CS additive forms a dynamic adsorption layer and desolvates zinc ions, preventing direct contact with water during the electrochemical process. The optimized electrolyte also exhibits advantages in regulating zinc ion fluxes and maintaining a stable hydrophobic interface, leading to enhanced cycling performance and reduced corrosion. CS enables stable zinc plating and stripping over extended periods, as well as high Coulombic efficiency and long-term cycling performance in full cells.