Zincophilic-Hydrophobic PAN/PMMA Nanofiber Membrane Toward High-Rate Dendrite-Free Zn Anode

Uncontrollable Zn dendrites and side reactions seriously downgrade the cycling stability of the Zn anode, and restrict the commercialization of aqueous zinc ion batteries. Here, PAN-based (PAN, PAN/PMMA) nanofiber membranes with uniform zincophilic-hydrophobic sites have been in-situ electrospun on Zn to effectively prevent harmful side reactions and control Zn plating/stripping behavior. The abundant highly-negative functional groups (C=N and C=O) of PAN/PMMA have strong coordination interactions with Zn2+, which can accelerate Zn2+ desolvation and increase the Zn2+ migration number. Furthermore, the even distribution of zincophilic sites can help create a uniform Zn deposition environment and enable horizontal Zn deposition. Simultaneously, the inherent hydrophobicity of the nonpolar carbon skeleton in PAN/PMMA can prevent Zn corrosion and hydrogen evolution reaction (HER) side reactions, thus improving the cycling stability of the Zn anode. As a result, PAN/PMMA@Zn symmetric cells demonstrated remarkable rate performance and long cycling stability, sustaining efficient operation for over 2000 cycles at 10 mA cm(- 2) with a low polarization voltage below 65 mV. This Zn anode modification strategy by in-situ constructed PAN-based nanofiber membrane has the advantages of simple-preparation, one-step membrane construction, binder-free, uniform distribution of functionalized units, which not only provides a specific scheme for developing advanced Zn anode but also lays a certain research foundation for developing separator-anode integrated Zn-based batteries.

Automated summary

In this study, PAN-based nanofiber membranes were in-situ electrospun on zinc to prevent harmful side reactions and control zinc plating/stripping behavior. The modified zinc anode showed improved cycling stability, remarkable rate performance, and long-term operation, making it a promising strategy for developing advanced zinc anodes.