Controlled deposition via a bifunctional layer enables dendrite-free zinc metal batteries

•A bifunctional layer was prepared in-situ on Zn metal anode.•The bifunctional layer can homogenize the electric field.•The epitaxial deposition of Zn (002) can be achieved.•The corrosion resistance of Zn anode has been improved.•Dendrite-free Zn plating/stripping is realized over 2200 h.