Boosting uniform nucleation and suppressing hydrogen evolution with an in-situ formed zinc hyaluronate protective film on zinc anodes.

Developing long-cycle stable Zn-ion batteries encounters significant challenges associated with Zn anodes. To address these issues, we propose an interface engineering strategy using an artificial protective layer called zinc hyaluronate (ZH) on the Zn anode surface. The ZH film acts as a barrier, preventing direct contact between Zn anode and electrolyte, reducing hydrogen evolution and corrosion. Its carboxyl and hydroxyl groups create uniform and plentiful nucleophilic sites for Zn2+ ions, promoting uniform Zn deposition and suppressing dendrite growth. Remarkably, a Zn//Zn symmetric cell assembled with ZH-decorated Zn foil (Zn@ZH) exhibits outstanding cycle life, lasting 3600 h at a current density of 5 mA cm-2 and a capacity density of 5 mAh cm-2, much better than cells with pristine Zn anode. Even under extremely tough conditions of 10 mA cm-2 and 10 mAh cm-2, the battery life exceeds 1300 h. Furthermore, the Zn@ZH//V2O5 full cell demonstrates superior capacity retention compared to the Zn//V2O5 cell after 1000 cycles at a current density of 10 A g-1. These results highlight the benefits of the artificial protective layer strategy for advanced Zn anodes, providing insights into the underlying mechanism and promoting the development of high-performance aqueous zinc ion batteries.