Hydrogen Bond Network‐Enhanced Zincophilic Hydroxypropyl Cellulose Hybrid Layer for an Ultra‐Stable Zinc Metal Anode

ABSTRACT As an earth‐abundant and natural biopolymer, cellulose has received significant attention in aqueous zinc‐ion batteries (AZIBs) due to its inherent sustainability and non‐toxicity, aligning perfectly with the core advantages of AZIBs. Nevertheless, the practical implementation of cellulose‐based materials is limited by their intrinsically low ionic conductivity. Herein, we introduce a novel zincophilic artificial protective layer by strategically hybridizing hydroxypropyl cellulose (HPC) with zinc trifluoromethanesulfonate on a zinc metal anode (HZ@Zn). Characterization and calculations demonstrate that the multi‐hydroxyl architecture of HPC constructs hydrogen bond networks, whereas the Zn 2+ ‐coordinated HPC domains function as preferential nucleation sites for zinc deposition. These interactions collectively enhance ion transport and accelerate desolvation kinetics. Additionally, the hybrid layer's mechanical flexibility and interfacial adhesion ensure the integrity of the artificial protective layer during long cycling. Thanks to this synergistic effect, HZ@Zn shows exceptional electrochemical performance, including a low desolvation activation energy of 14.38 kJ mol −1 and ultra‐long cycling stability. Symmetric cells demonstrate exceptional longevity, exceeding 9,500 h at 0.5 mA cm −2 /0.25 mAh cm −2 , whereas HZ@Zn‖PANI full cells maintain 89.8% capacity retention after 4000 cycles at 5 A g −1 . This study establishes biopolymers as versatile platforms for effectively stabilizing the zinc metal anode.