Manipulating alloying reaction to achieve the stable and dendrite-free zinc metal anodes

Zinc metal anode has serious dendrites and corrosion issues in the mild electrolyte, which greatly hinder the commercialization of aqueous zinc-ion batteries. Herein, zinc-amalgam (Zn 3 Hg) alloy anode has been prepared and displays a unique synergistic zinc plating/stripping and alloying/dealloying reaction mechanism. The ultrafast zinc ions diffusion in Zn 3 Hg and the alloying reaction of Zn 3 Hg with Zn ions effectively suppress the dendrites growth and skillfully address corrosion issues. Consequently, the Zn 3 Hg anode expresses long cycle life of 2000 h at 1 mA cm −2 /1 mAh cm −2 and exhibits the lowest voltage hysteresis of only 8.0 mV that we know so far. Even at 5 mA cm −2 /5 mAh cm −2 and 10 mA cm −2 /10 mAh cm −2 , the Zn 3 Hg anode also exhibits excellent cycling stability and low voltage hysteresis. Moreover, zinc ion capacitors composed of Zn 3 Hg anode and active carbon cathode still possess a specific capacity of 61 mAh/g after 5000 cycles at 1 A/g. The Zn 3 Hg anode enriches the varieties of zinc alloy anodes and provides a new development path for constructing stable and dendrite-free zinc metal anodes.