Ultrafast construction of porous zincophilic interphase within 10 s toward stable Zn metal anode through a selective zinc crystal growth

Zn metal anode (ZMA) is a promising candidate of aqueous Zn-ion batteries (ZIBs) for its high theoretical capacity and low redox potential. However, the cycle stability of ZMAs is adversely affected by dendritic growth and side reactions. Herein, a porous 3D-Zn host coated with zincophilic Sn layer (Sn@3D-Zn) is obtained via an ultrafast OTf−-assisted etching strategy within 10 s at room temperature. Through experimental results and theoretic calculations, we explore the ultrafast etching mechanism of OTf− anions and propose the unique growth model of Sn@3D-Zn through previously unreported surface miniature primary cell reactions. Compared to bare Zn, the unique 3D-Zn host with enhanced Zn-affinitive Sn layer affords more Zn nucleation sites and lowers deposition energy barrier that promotes the lateral growth of Zn electrodeposits along Zn(002). Consequently, the Sn@3D-Zn anode exhibits an extraordinary cycling lifespan of 4000 (or 2000) h at 0.5 (or 3) mA cm−2 with a significantly lower polarization overpotential. More encouragingly, when assembled with polyaniline-intercalated V2O5 cathode, the aqueous ZIBs also exhibit high performance with improved rate performance and cycle stability. Given the ultrafast fabrication and improved reversibility of ZMAs, our work provides a striking example of artificial porous zincophilic interphase layers for better aqueous ZIBs.