Abstract In a previous study, we demonstrated that the hydrophobic protic amide-type ionic liquid (IL), protonated-betaine bis((trifluoromethyl)sulfonyl)amide ([Hbet][TFSA]), is an effective electrolyte for silver oxide (Ag₂O) dissolution and silver metal electrodeposition, enabling silver recovery from spent Ag₂O coin batteries. However, spent batteries contain metallic silver produced during discharge. Furthermore, the dissolved Ag(I) species in [Hbet][TFSA] lacks long-term stability, likely due to photochemical reactions between Ag(I) and H₂O in the wet IL. In this study, thiourea (TU) was introduced to stabilize the Ag(I) species via coordination, while hydrogen peroxide (H₂O₂) was employed as an oxidizing agent to convert metallic Ag into Ag(I) ions. Consequently, this system may offer a sustainable approach for recovering silver from spent Ag₂O coin batteries without requiring corrosive mineral acids.