ELECTROCHEMICAL PERFORMANCE OF ANTIMONY-MODIFIED POROUS LAMELLAR ZINC ALLOY ANODE IN ALKALINE AQUEOUS ELECTROLYTE

Muhammad Afiq Irfan Mohd Shumiri; Abdillah Sani Mohd Najib; Nor Akmal Fadil

Muhammad Afiq Irfan Mohd Shumiri Materials Research and Consultancy Group, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia.
Abdillah Sani Mohd Najib Materials Research and Consultancy Group, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia.
Nor Akmal Fadil Materials Research and Consultancy Group, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia.

Keywords: Zinc anode, surface modification, electrochemical performance, lamellar porous structure

Abstract

Metallic zinc is one of the most attractive anode materials for post‑lithium batteries due to its natural abundance, safety, low cost and high theoretical capacity. However, it often suffers from severe polarization and poor reversibility, which hinder the practical application in aqueous alkaline rechargeable zinc‑ion batteries. Herein, this work presents antimony-modified porous lamellar zinc anode (Sb-pZn) as a promising high-performance negative electrode. The porous structure was fabricated by chemical dealloying of eutectic Zn-Al alloy, in which the less noble Al component was selectively removed in sodium hydroxide (NaOH) solution. This process produces a well-defined lamellar pattern with aligned porous channels, providing high surface area that facilitates efficient ion transport and enhances electrochemical stability. Surface modification was performed through galvanic replacement reaction in antimony trichloride (SbCl₃) solution. This introduces Sb sites that promote uniform Zn nucleation. As a result, Sb-pZn anode with Zn lamellar thickness of ~2920 nm (Sb-pZn-2920) shows improved Zn deposition behavior, with an ultralow nucleation overpotential of 101.3 mV even at high current density of 0.2 mA/cm². Cyclic voltammetry shows better redox kinetics with stronger peak currents and reduced peak separation of 0.736 V, while electrochemical impedance spectroscopy confirms a notable decrease in charge transfer resistance from 4.238 Ω for bare Zn to 1.770 Ω for Sb-pZn-2920. The combined effects of Sb incorporation and the tailored porous structure effectively reduce polarization and enhance overall electrochemical performance. This study offers a simple and scalable strategy for developing high-performance Zn anodes and provides valuable insights for advancing next-generation aqueous Zn-based energy storage systems.