Regulating Desolvation and Directional Ion Flux by an Ion-Capturing Carboxyl-Functionalized Separator for Stable Aqueous Zinc Batteries.

The wide application of aqueous zinc-ion batteries (AZIBs) is limited by uncontrolled zinc dendrite growth and sluggish ion transport dynamics. This study develops a carboxyl-functionalized separator integrated with the metal-organic framework MOF-801 on a glass fiber substrate (MGS) via an in situ growth strategy. The innovative design features dual mechanisms: fundamentally, the uniform nanochannels of MOF-801 regulate Zn flux distribution through spatial confinement effects. Beyond this, DFT calculations and Raman analyses demonstrate that the grafted carboxyl groups selectively capture Zn via dynamic coordination interactions, simultaneously inducing localized high-concentration electrolyte formation within the channels and effectively suppressing interfacial concentration polarization. The MGS enables Zn||Zn cells to achieve exceptional stability exceeding 8000 h at 1 mA cm and practical Zn||MnO pouch cells to deliver a capacity of 108 mA h g at 0.1 A g. This work provides novel insights for the design of multifunctional separators and the regulation of metal ion transport.