A dynamic organic-inorganic bilayer solid/electrolyte interphase employed L-carnosine additive for highly stable zinc metal anode

The construction of a solid/electrolyte interphase (SEI) is a critical aspect to control the highly stable plating/stripping of Zn metal anode and side reactions for aqueous zinc-ion batteries (AZIBs). Here, we employ l-carnosine (HL), a dipeptide regulating pH in human cells, as an electrolyte additive to construct a dynamic organic-inorganic bilayer SEI to stabilize the Zn anode. The bilayer SEI consists of an amorphous organic inner layer and a ZnCO₃-rich crystalline outer layer. The dynamic organic inner layer reduces Zn²⁺ deposition resistance and promotes uniform Zn²⁺ flux, thereby mitigating dendrite formation. While the ordered crystalline outer layer effectively isolates water molecules, thereby enhancing the overall mechanical strength and stability of the SEI. As a result, the cycle life of the Zn||Zn symmetric cell exceeds 5500 h at 1 mA cm⁻², 1 mAh cm⁻², and 1450 h at a high current density of 10 mA cm⁻², 10 mAh cm⁻². The Zn||NVO full cell also presents a discharge specific capacity of more than 180 mAh g⁻¹ and close to 100% coulomb efficiency (CE) after a stable cycling of 2000 cycles.