Perfluoro-1-butanesulfonic acid etching strategy for dendrite suppression in aqueous zinc metal batteries

Abstract

Perfluoro-1-butanesulfonic acid (PFBS) was used to etch on the surface of a zinc anode to introduce a 3D C₄F₉O₃S–Zn interface layer with unique fluorine groups (Zn@PFBS) to inhibit the formation of dendrites. The C–F chains in the Zn@PFBS coating enhance the anode hydrophobicity of the zinc metal, which not only suppresses the HER of the surface of the zinc metal, but also strengthens the corrosion resistance of the zinc metal. Meanwhile, –SO₃⁻ in the coating enhanced the binding energy with Zn²⁺, which acted as a nucleation site on the surface of the zinc anode to induce the uniform deposition of Zn²⁺ and inhibited the disordered growth of zinc dendrites. As a result, the symmetric battery assembled with the Zn@PFBS anode achieved a stable cycling of 6200 cycles at 5 mA cm⁻² to 1 mA h cm⁻². Meanwhile, the Zn@PFBS anode exhibited a higher cycling performance with a capacity retention rate of 78.6% after 1000 cycles in a Zn@PFBS//Na₅V₁₂O₃₂ (NVO) full cell.