High-entropy alloy catalysts for advanced hydrogen-production zinc-based batteries

Abstract

H₂-producing zinc batteries hold promise as an electrochemical energy technology due to their unique ability to simultaneously generate electricity and hydrogen. However, their widespread adoption and commercialization have been hindered by low power density and limited hydrogen yield rates. This study tackles these challenges by developing a high-entropy alloy (HEA) catalyst (FeNiCuWRu), which is implemented by virtue of computational high-throughput screening to select appropriate element combinations from the vast conformational space of HEAs. Theoretical calculations based on machine learning potentials further identify Cu and Ni as the primary active sites for the hydrogen evolution reaction (HER). This theoretical prediction is validated by the newly developed FeNiCuWRu high-entropy alloy (HEA) electrocatalyst, which exhibits highly desirable activity for both acidic HER and alkaline OER. Inspired by this, we established an innovative rechargeable hybrid alkali/acid zinc-based battery using the FeNiCuWRu HEA as the electrocatalyst. This hybrid battery not only achieves industrial-grade hydrogen production at high current densities but also delivers a maximum power density of 537 mW cm⁻², surpassing the vast majority of previously reported alkaline Zn–air batteries. A pilot battery stack capable of simultaneously generating electricity and hydrogen has been constructed, demonstrating the practical feasibility of potential applications in various scenarios.