Interfacial\nChemistry Modulation via Amphoteric Glycine\nfor a Highly Reversible Zinc Anode

Zn\nmetal is thermodynamically unstable in aqueous electrolytes,\nwhich induces dendrite growth and ongoing parasitic reactions at the\ninterface during the plating process and even during shelf time, resulting\nin rapid battery failure and hindering the practical application of\naqueous Zn ion batteries. In this work, glycine, a common multifunctional\nadditive, is utilized to modulate the solvation shell structure and\nenhance the interfacial stability to guard the reversibility and stability\nof the Zn anode. Apart from partially replacing the original SO42– in the contact ion pair of Zn2+[H2O]5·OSO32– complexes to suppress the formation of Zn4(OH)6SO4·xH2O byproducts at\nthe interface, glycine molecules can also form a water-poor electrical\ndouble layer on the zinc metal surface during resting and be further\nreduced to build in situ a ZnS-rich solid electrolyte\ninterphase (SEI) layer during cycling, which further suppresses side\nreactions and the random growth of Zn dendrites in the whole process.\nAs expected, the cycle life of the symmetrical cells reaches over\n3200 h in glycine-containing electrolytes. In addition, the Zn//NVO\nfull cell shows exceptional cycling stability for 3000 cycles at 5\nA g–1. Given the low-cost superiority of glycine,\nthe proposed strategy for interfacial chemistry modulation shows considerable\npotential in promoting the commercialization progress of aqueous batteries.