Three-dimensional Porous Alloy Host for Highly Stable and Dendrite-Free Zinc Metal Anode

Aqueous zinc-ion batteries (ZIBs) are considered to be one of the most attractive energy storage systems due to their environmental friendliness, low cost, high safety and high energy density. However, the uncontrollable Zn dendrites impose limitations on the durability of ZIBs. Herein, a three-dimensional Fe-Ni (3DP-FeNi) alloy with uniform and small pores, good wettability and high hydrogen evolution overpotential is prepared by electrochemically dealloying reaction in molten salts and further used as a host for Zn (3DP-FeNi@Zn) metal anode. The 3DP-FeNi@Zn anode exhibits a high stripping/plating coulombic efficiency of 98.8% and stable cycling over 700 h at 0.5 mA cm −2 without dendrite formation, which is superior to that of bare Zn and Ni foam loaded Zn (Ni@Zn). Furthermore, when 3DP-FeNi@Zn anode is coupled with porous carbon loaded I 2 (PC@I 2 ) cathode, the full battery of 3DP-FeNi@Zn//PC@I 2 can yield a capacity of 123.3 mAh g −1 (on the basis of I 2 ) after 5000 cycles at 1 A g −1 without short circuit in comparison to less than 870 cycles for batteries built on bare Zn and Ni@Zn. This work provides an effective strategy to improve the cycling stability of ZIBs anode.