Abstract:
The extremely short cycling life of Zn-anode under combined high areal capacity and current density remains a key barrier to the large-scale AZIB deployment. Herein, it is experimentally and theoretically demonstrated that adenine, a multirole zincophilic biomolecular electrolyte additive, outperforms other nucleobases, promoting Zn deposition toward (100) plane, notably enhancing cycling stability under simultaneous ultrahigh areal capacity and current density. Owing to its multiple nitrogen atoms with varying basicity, adenine engages in multifaceted interactions, including coordination with solvated Zn2+ ions, adsorption on the Zn(002) plane, and H-bonding with both solvated and bulk water molecules. These synergistic interactions passivate the thermodynamically stable Zn(002) plane, suppress interfacial water-induced HER and byproduct formation, and promote dendrite-free Zn deposition along the high-energy (100) plane. The resulting crystallographic regulation results in long-cycle-life Zn stripping/plating even under practically demanding harsh conditions of ultrahigh areal capacity and current density. In an adenine-boosted Zn||Zn symmetric cell achieves a cycle-life of 1060 h under combined conditions of 40 mA cm-2 and 40 mAh cm-2 and a record cumulative capacity of 42400 mAh cm-2. Current findings highlight the potential of zincophilic biomolecular additive design principles in overcoming key interfacial challenges, enabling a distinctive, environmentally benign pathway toward realizing large-scale AZIB development.
