Multifunctional Silanol-Based Film-Forming Additive for Stable Zn Anode

Abstract

Aqueous zinc ion batteries (AZIBs) have garnered significant attention due to their advantages, including high safety, a straightforward manufacturing process, abundant resource availability, and high theoretical capacity. Nevertheless, the industrial application of AZIBs is impeded by the undesirable growth of dendrites and side reactions on the Zn anode. In this study, [3-(trimethoxysilyl) propyl] urea (3TMS) is utilized as an electrolyte additive to develop a solid/electrolyte interphase (SEI) film on the surface of Zn anode. The in situ formed SEI layer not only prevents side reactions form the direct contact of Zn anode with water but also induces preferential Zn deposition along the (002) crystal plane, suppressing dendrite growth. These synergistic functions enable the Zn anode with ultralong cycle life of over 6000 h at the current density of 1 mA cm⁻² with the areal capacity of 1 mAh cm⁻², as well as high coulombic efficiency of 99.34% after 750 cycles. Moreover, the Zn//V₂O₅ full cells with 3TMS additive display a high specific capacity of 114.4 mAh g⁻¹ at a current density of 0.5 A g⁻¹ after 1000 cycles. This work provides a simple yet feasible approach to develop stable Zn anode toward high-performance AZIBs.