Stable anode-free zinc-ion batteries enabled by alloy network-modulated zinc deposition interface

Abstract

Newly-proposed anode-free zinc-ion batteries (ZIBs) are promising to remarkably enhance the energy density of ZIBs, but are restricted by the unfavorable zinc deposition interface that causes poor cycling stability. Herein, we report a Cu-Zn alloy network-modulated zinc deposition interface to achieve stable anode-free ZIBs. The alloy network can not only stabilize the zinc deposition interface by suppressing 2D diffusion and corrosion reactions but also enhance zinc plating/stripping kinetics by accelerating zinc desolvation and nucleation processes. Consequently, the alloy network-modulated zinc deposition interface realizes high coulombic efficiency of 99.2% and high stability. As proof, Zn//Zn symmetric cells with the alloy network-modulated zinc deposition interface present long operation lifetimes of 1900 h at 1 mA/cm2 and 1200 h at 5 mA/cm2, significantly superior to Zn//Zn symmetric cells with unmodified zinc deposition interface (whose operation lifetime is shorter than 50 h), and meanwhile, Zn3V3O8 cathode-based ZIBs with the alloy network-modified zinc anodes show notably enhanced rate capability and cycling performance than ZIBs with bare zinc anodes. As expected, the alloy network-modulated zinc deposition interface enables anode-free ZIBs with Zn3V3O8 cathodes to deliver superior cycling stability, better than most currently-reported anode-free ZIBs. This work provides new thinking in constructing high-performance anode-free ZIBs and promotes the development of ZIBs.