Green Degradable Additive: γ-Aminobutyric Acid for High-Performance Sustainable Zinc-Ion Batteries

To advance the sustainability of aqueous zinc-ion batteries (AZIBs), this study introduces γ-aminobutyric acid (GABA), a biodegradable and natural organic small molecule, as an economically viable electrolyte additive to overcome commercialization barriers such as dendrite proliferation and parasitic side reactions for achieving ultrastable zinc metal anodes. Theoretical and experimental results confirm that GABA undergoes preferential chemisorption on the zinc surface. This adsorbed film generates a water-deficient interfacial microenvironment that robustly suppresses detrimental side reactions. At the same time, the GABA adsorption layer guides the homogeneous electric-field. In addition, GABA molecules partially replace H₂O molecules in the solvation shell of Zn²⁺. Remarkably, the GABA-based electrolyte enables Zn//Zn cells to have an outstanding cycling life of nearly 3000 h at 5 mA cm^-2, surpassing the performance of the pure ZnSO₄ electrolyte by a factor of 10. Moreover, in the Zn//Cu asymmetric cell, a highly reversible Zn plating/stripping process for over 13,000 cycles. Furthermore, the full-cell configurations exhibit outstanding electrochemical durability. The Zn//V₂O₅ cell maintains an impressive capacity retention of 83.5% over 2200 cycles, and the Zn//NVO cell demonstrates ultralong cyclability exceeding 10,000 cycles at 5 A g^-1. This research highlights the potential of eco-friendly and cost-effective electrolyte additives in promoting the development of AZIBs.