Enhanced Performance and Durability of Zinc–Air Batteries Utilizing W-Doped Cobalt Pentlandite Catalysts

Abstract

The design of cost-effective electrocatalysts is critical for advancing sustainable energy technologies, particularly for key reactions like the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) in water electrolyzers and metal–air batteries. Cobalt pentlandite (CNFS) has emerged as a promising candidate, offering high conductivity, stability, and the advantage of using abundant elements. In this study, density functional theory (DFT) calculations reveal that tungsten (W) doping in CNFS, combined with an increased concentration of sulfur vacancies, can effectively shift the d-band center downward enhancing metal-sulfur orbital hybridization. These modifications facilitate the desorption of oxygen intermediate while maintaining structural integrity. Additionally, the engineering of this material with a hollow architecture further increases active site exposure, significantly improving catalytic activity. As a result of this multifaceted approach, the W-doped CNFS catalyst achieves a remarkably low OER overpotential of 241 mV at 50 mA cm⁻², alongside enhanced ORR activity. Furthermore, the catalyst demonstrates excellent performance in rechargeable zinc–air batteries (ZABs), achieving a peak power density of 100 mW cm⁻² and sustaining over 650 h of cycling at 4 mA cm⁻². Overall, this study presents a viable strategy for improving ZAB performance and reducing costs by utilizing efficient and cost-effective metal sulfides with a cobalt pentlandite structure.