Real-time regulation of zinc deposition/stripping by self-assembled molecule brush targeting proton for highly reversible Zn-ion battery

Currently, zinc anodes are facing problems such as the growth of zinc dendrites and the frequent occurrence of side reactions, while existing additive strategies are still challenging due to the poor stability of the adsorption layer and the ambiguous mechanisms of action. In this study, a highly stable Vani molecular brush additive was designed. The additive effectively inhibits H2 generation by targeting and anchoring H+ in the inner Helmholtz layer, and reduces the water activity by constructing an enhanced hydrogen bonding network through the interaction with water molecules, thus inhibiting the parasitic side reactions on the zinc anode. In addition, the dynamic interfacial molecular layer can regulate and buffer the interfacial Zn2+ for highly reversible plating/stripping. Experiments show that the symmetric cell cycle life is as long as 3760 h at a Vani content of only 2 × 10−3 g L−1 with a current density of 5 mA cm−2. The cycle life of the Zn||MnO2 and Zn||Zn0.58V2O5‧H2O full battery is significantly improved. This study deepens the understanding of the working mechanism of the zinc electrode interface and provides new ideas for non-sacrificial trace additive design.Graphic abstractTrace additive Vani is introduced to stabilize the zinc anode by anchoring H+ in the inner Helmholtz layer and enhancing the O–H bond order of water.Download: Download high-res image (167KB)Download: Download full-size image