Interfacial Engineering with a Conjugated Conductive Polymer for a Highly Reversible Zn Anode

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Science

Background:

• Zinc anodes in rechargeable batteries face challenges like dendrite formation, hydrogen evolution, and corrosion.
• These issues stem from the complex interface between the zinc electrode and the electrolyte.
• Effective interfacial engineering is crucial for stable and efficient zinc metal battery operation.

Purpose of the Study:

• To develop an interfacial engineering strategy for protecting zinc anodes.
• To promote homogeneous zinc deposition and suppress side reactions.
• To enhance the performance and stability of aqueous rechargeable zinc batteries.

Main Methods:

• Fabrication of conjugated cyclized polyacrylonitrile (cPAN) polymer nanofibers.
• Application of cPAN nanofibers as a hydrophobic protective layer on the zinc anode.
• Investigation of zinc ion transport and deposition behavior at the electrode/electrolyte interface.
• Electrochemical testing of cPAN-coated zinc anodes in aqueous electrolytes.

Main Results:

• The cPAN layer effectively inhibited water contact, reducing side reactions and improving anticorrosion properties.
• Abundant zincophilic sites on cPAN nanofibers promoted Zn2+ ion transport, leading to homogeneous, dendrite-free zinc deposition.
• The cPAN-coated Zn anode (cPAN@Zn) exhibited high coulombic efficiency (>99.9%) and exceptional cycling stability (>2000 h at 1 mA cm-2, >16,000 cycles at 10 mA cm-2).
• Excellent electrochemical kinetics were observed with a low overpotential (<0.15 V at 50 mA cm-2).

Conclusions:

• Conjugated cyclized polyacrylonitrile nanofibers serve as an effective interfacial modifier for zinc anodes.
• This approach successfully addresses key challenges in zinc metal batteries, enabling dendrite-free deposition and enhanced stability.
• The findings offer valuable insights into utilizing organic interfacial engineering with conjugated polymers for advanced aqueous rechargeable zinc energy storage systems.