Project Overview

Zinc-air batteries (ZABs) are promising energy storage devices due to their high theoretical energy density, low cost, high abundance of zinc, environmental friendliness, intrinsic safety, stable discharge voltage, and long shelf-life. The air electrode is considered the most significant and complicated part of a ZAB, as it hosts the sluggish and multi-electron oxygen reduction (ORR) and evolution (OER) reactions, contributing to high overpotentials and reduced efficiency. While carbon-based materials are commonly employed as the substrate in air electrode for ZABs, carbon-based materials suffer from several drawbacks, including corrosion at high potentials, loss of electrochemically active surface area, blockage of catalytic sites by carbonate precipitates, hindered oxygen diffusion, and overall performance degradation, especially at high current densities. In conventional air electrode fabrication, the catalyst layer is coated onto a conductive substrate using binders which causes increased interface resistance, blocked active sites, degradation and detachment, complex fabrication, uncontrolled microstructures, and gas bubble formation in the air electrode, which hinder the performance. As a solution, this project focuses on developing a high-performance, non-carbon-based, binder-free air electrode incorporating bifunctional electrocatalyst(s) for rechargeable ZABs to overcome the drawbacks of conventional air electrodes.