High performance Zn anodes enabled by a multifunctional biopolymeric protective layer for a dendrite-free aqueous zinc-based battery

Abstract

Rechargeable zinc-based batteries are expected to be the next generation energy storage system because of their high specific capacity, low redox potential, low cost, eco-friendliness, and abundant reserves. Nevertheless, their large-scale applicability is restricted due to water-induced side reactions, and the uneven plating/stripping of Zn on the anodes. Herein, an artificial protective layer acting as a desolvation layer and a zinc ion flux regulator is proposed for the reconstruction of the Zn/electrolyte interface and to promote the formation of an ultra-even amorphous solid–electrolyte interface (SEI) on Zn metal. As a consequence, the modified Zn anode displays a strong zincophilic property and decreasing interfacial impedance. The artificial layer obtained can inhibit the side reactions and induce the uniform deposition of zinc ions to avoid Zn dendrite formation in the charge/discharge process. With this advantage, the dendrite-free Zn anode exhibits a higher cycling stability (over 1200 h at 2 mA cm⁻²) than that of the bare Zn anode. This is also confirmed in the full Zn‖V₂O₅ battery with an ultrahigh discharge capacity after 1000 cycles.