Synergistic Cation-π Interactions and PEDOT-Based Protective Double-Layer for High Performance Zinc Anode

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Effective zinc ion (Zn²⁺) transport is critical for solid electrolyte interphase (SEI) functionality in zinc-based batteries.
• Controlling Zn²⁺ flux is essential for enhancing battery performance and cycle life.

Purpose of the Study:

• To demonstrate the incorporation of cation-π interactions within the SEI for improved Zn²⁺ transportation.
• To develop a novel artificial SEI that facilitates uniform zinc ion flux and enhances battery stability.

Main Methods:

• Immobilization of 4-amino-p-terphenyl (TPA) onto a poly(3,4-ethylenedioxythiophene) (PEDOT) matrix to create a cation-π interaction network.
• Fabrication of a thin, robust polymeric TPA/PEDOT (TP) film via interfacial polymerization for use as an artificial SEI.
• Testing of symmetrical and asymmetrical zinc cells utilizing the TP artificial SEI.

Main Results:

• The TP artificial SEI exhibits exceptional cycling stability with low overpotential and high reversibility of Zn plating/stripping.
• Symmetrical cells achieved over 3200 hours of stable cycling at 1 mA cm⁻² and 1 mAh cm⁻².
• Asymmetrical cells demonstrated 3000 stable cycles with 99.78% Coulomb efficiency, even under challenging conditions like lean electrolyte and low N/P ratio.

Conclusions:

• The integration of cation-π interactions in artificial SEI is a viable strategy for controlling Zn²⁺ transport.
• The developed TP artificial SEI significantly enhances the stability and performance of zinc-based battery systems.
• This approach offers a promising pathway for developing next-generation high-performance and long-lasting zinc batteries.