Multi-Functional Additive with Triple Regulation Mechanisms for Long-Life Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) have attracted significant interest due to their low cost and high safety. The lifetime of ZIBs is highly associated with several critical factors, including dendrite growth, hydrogen evolution reactions (HER), and irreversible parasitic reactions. Although the adoption of electrolyte additives can greatly mitigate such issues, the fundamental regulation mechanisms remain unclear. In this work, L-glutamic acid (Glu), serving as an electrolyte additive, is proposed to construct long-lifespan ZIBs with outstanding capacity. Crucially, a systematic and fundamental clarification of the roles of Glu is carried out, which includes tailored solvation structures, accelerated desolvation kinetics, and reinforced interfacial interactions. Consequently, the Zn||Zn symmetrical battery delivers a remarkable cycling stability of as long as 4,500 h at 5 mA cm^-2 and 1.25 mAh cm^-2. Furthermore, the developed Zn||MnO₂ full battery achieved a significant capacity improvement and maintains an outstanding capacity retention of 80.41% even after 1,000 h at a current density of 1 A g^-1.