Zwitterionic Binder-Engineered Interfaces Enable Anti-Pulverization and Long-Cycling Anode-Free Zn Batteries

Anode-free zinc batteries (AFZBs) offer exceptional theoretical energy density, yet suffer from severe structural pulverization and dendritic growth during cycling, leading to rapid capacity decay and poor reversibility. To address these challenges, this work proposes a novel zwitterionic binder strategy that concurrently suppresses Zn pulverization and stabilizes the electrode-electrolyte interface. Incorporation of a rationally designed zwitterionic polymer binder (ZPB) endows the engineered Zn anode with unprecedented mechanical robustness and homogeneous ion flux distribution. The zwitterionic architecture effectively alleviates deposition-induced volume changes through viscoelastic stress dissipation and reduces the nucleation overpotential of zinc through interactions between ions and functional groups. Benefiting from these comprehensive properties, impressive Zn plating/stripping Coulombic efficiencies (CEs) of 99.5% are achieved for 1800 cycles in asymmetric cells. Furthermore, the ZPB-engineered anode-free full ZPB/C@Cu||NVO batteries deliver remarkable cycling stability of over 1000 cycles with 86% capacity retention at a practical current density of 2 A g^-1. This work establishes a structure-functionality-performance correlation between zwitterionic molecular design and interfacial stabilization mechanisms, providing a scalable design strategy for practical metal anode-free battery systems.