Glycine‐Driven Dynamic Interfacial pH Buffering Enables Highly Reversible Zinc Metal Anodes

ABSTRACT Aqueous zinc‐ion batteries are severely hindered by interfacial side reactions including dendrite growth and by‐product accumulation, primarily caused by local pH fluctuations at the Zn/electrolyte interface. Here, we propose a dynamic interfacial pH‐buffering strategy using glycine (Gly), which simultaneously anchors onto the Zn surface and regulates proton transfer through its reversible acid–base equilibria. In situ pH mapping with an ultramicroelectrode probe directly confirms that Gly effectively suppresses interfacial alkalization and maintains a stable interfacial environment during Zn plating/stripping. Benefiting from this local buffering effect, the Gly‐containing electrolyte achieves a Coulombic efficiency (CE) of 99.5% in Zn||Cu cells, stable cycling over 1000 h in symmetric cells, and durable cycling for 2000 cycles in Zn||NaV 3 O 8 full cells. This work establishes interfacial pH stabilization as an important design criterion for electrolyte‐additive engineering in aqueous Zn batteries.