Multifunctional SEI-like structure coating stabilizing Zn anodes at a large current and capacity

Abstract

The development and application of aqueous zinc-ion batteries still face some obstacles, such as dendrite growth and side reactions triggered by active water. Here, we constructed a PVA@SR-ZnMoO₄ multifunctional coating on the Zn anode with an SEI-like structure (SR refers to SO₄²⁻ receptor). The PVA@SR outer layer can give the coating some flexibility while enhancing Zn²⁺ mobility and dispersion. The ZnMoO₄ inner layer can effectively inhibit dendrite growth and side reactions. Importantly, a fast Zn²⁺ migration pathway can be established between PVA and ZnMoO₄ in the inorganic–organic composite inner layer, ensuring high-current operation of the Zn anode. Thanks to the “mutual cooperation”, the Zn anode exhibits a high Coulomb efficiency (CE) of 99.42% and good cycling stability of 1700 h at 5 mA cm⁻² and 5 mA h cm⁻². Moreover, the Zn/α-MnO₂ full cell can maintain a residual capacity of 141.7 mA h g⁻¹ without capacity decay after 1000 cycles at 1.0 A g⁻¹.