Adjusting zinc deposition behaviors by a modified separator to acquire zinc anodes for aqueous rechargeable zinc-ion batteries

Abstract

Aqueous rechargeable zinc ion batteries (ARZIBs) are ideal for massive and longstanding energy storage applications because of their excellent security and low operation cost. Nevertheless, ARZIBs are subject to the severe corrosion reaction of zinc metal anodes that is derived from the thermodynamic unsteadiness of the zinc anodes in aqueous solution, as well as zinc dendrite growth originating from uncontrolled zinc deposition. Herein, we created a separator by coating a thin piece of polypropylene (PP) with a compound consisting of zinc trifluoromethanesulfonate [Zn(OTf)₂] and poly(vinylidene fluoride-hexafluoropropylene (PVDF-HFP). Consequently, the severe corrosion reaction of the zinc metal anodes and the profuse formation of zinc dendrites were effectively mitigated by the novel PP separator, which prolonged the lifetime of the zinc metal anodes. When a zinc metal plating layer was used with preferential (002) crystallographic orientation, the cyclic performance over 1100 h of the symmetrical Zn∥Zn battery based on the novel separator was steady. Additionally, the Zn∥MnO₂ batteries exhibited an impressive specific capacity and competitive long durability of 75.5% over 500 cycles at a current density of 0.1 A g⁻¹. With this work, we intend to set the standard for designing novel separators in the construction of advanced zinc anodes for high-performance ARZIBs.