Construction of a Smart Gelatin Interphase to Stabilize Aqueous Zn-Metal Anode

Rechargeable aqueous Zn-metal batteries (ZMBs) have attracted widespread attention due to their safety, high rate and low cost beyond Li-metal batteries (LMBs). However, due to the lack of the solid electrolyte interphase (SEI) film, anabatic problems such as dendrites, side reactions and hydrogen generation severely restrict the commercial applications of ZMBs. Herein, a smart gelatin interphase with self-adaptive behavior is constructed to stabilize the Zn-metal anode, which enduringly limits the unscrupulous attack of the electrolyte to the anode and free diffusion of Zn 2+ ion before reduction. In view of these synergistic effect, the gelatin modified Zn anode (Zn@Gel) remains dendrite-free and significantly reduced side-reaction products during either aging or plating/stripping processes, delivering a long running lifetime over 2500 h (1 mAh cm -2 , 0.2 mA cm -2 ). After 300 cycles at a current density of 365 mA g -1 , the capacity retention of the V 2 O 5 full cell with Zn@Gel anode is ~2.7 times that with the bare Zn anode. This strategy with self-adaptive conformal interphase represents a promising approach to stabilize metal anodes in aqueous electrolytes, and even can be extended to organic electrolytes.