In-Situ Solid Electrolyte Interface via Dual Reaction Strategy for Highly Reversible Zinc Anode.

Abstract

In-situ construction of solid electrolyte interfaces (SEI) is an effective strategy to enhance the reversibility of zinc (Zn) anodes. However, in-situ SEI to afford high reversibility under high current density conditions (≥ 20 mA cm-2) is highly desired yet extremely challenging. Herein, we propose a dual reaction strategy of spontaneous electrostatic reaction and electrochemical decomposition for the in-situ construction of SEI, which is composed of organic-rich upper layer and inorganic-rich inner layer. Particularly, in-situ SEI performs as "growth binder" at small current density and "orientation regulator" at high current density, which significantly suppresses side reactions and dendrite growth. The in-situ SEI affords the record-breaking reversibility of Zn anode under practical conditions, Zn//Zn symmetric cells can stably cycle for over 1300 h and 400 h at current densities of 50 mA cm-2 and 100 mA cm-2, respectively, showcasing an exceptional cumulative capacity of 67.5 Ah cm-2. Furthermore, the practicality of this in-situ SEI is verified in Zn//PANI pouch cells with high mass loading of 25.48 mg cm-2. This work provides a universal strategy to design advanced SEI for practical Zn-ion batteries.