Stabilizing Interface pH by N‐Modified Graphdiyne for Dendrite‐Free and High‐Rate Aqueous Zn‐Ion Batteries

Abstract

Abstract Zn dendrite issue was intensively studied via tuning zinc ion flux. pH change seriously influences dendrite formation, while its importance has not been revealed. Here, we construct a N‐modification graphdiyne interface (NGI) to stabilize pH by mediating hydrated zinc ion desolvation. Operando pH detection reveals pH stabilization by NGI. This works with pores in NGI to achieve dendrite‐free Zn deposition and an increased symmetric cell lifespan by 116 times. Experimental and theoretical results owe pH stabilization to desolvation with a reduced activation energy achieved by electron transfer from solvation sheath to N atom. The efficient desolvation ensures that electron directly transfers from substrate to Zn 2+ (rather than the coordinated H 2 O), avoiding O−H bond splitting. Hence, Zn‐V 6 O 13 battery achieves a long lifespan at 20.65 mA cm −2 and 1.07 mAh cm −2 . This work reveals the significance of interface pH and provides a new approach to address Zn dendrite issue.