Iron phthalocyanine assisted bifunctional oxygen electrocatalyst for high-performance and long-life rechargeable zinc–air batteries

Abstract

The development of high-performance and long-lasting rechargeable zinc–air batteries (ZABs) requires efficient and durable bifunctional oxygen electrocatalysts that can facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). This advancement is crucial for enhancing the overall performance and longevity of rechargeable ZABs. However, it remains highly challenging to integrate independent ORR and OER active sites into a catalyst with high bifunctional activity. Herein, we report a simple approach to design a nonprecious metal catalyst by immobilizing iron phthalocyanine (FePc) onto Ni nanoparticle-loaded porous graphene-based heterostructures (PGHS) via π–π interactions. Owing to these interactions the resultant FePc@Ni-PGHS catalyst synergistically facilitate the ORR and OER bifunctional electrocatalytic performance. Consequently, as an air electrode in ZAB, it achieves a peak power density of 152 mW cm⁻², a large specific capacity of 862 mAh g⁻¹, and stable cycling performance for 124 h. These findings emphasize its potential as a low-cost alternative to precious metal-based electrocatalysts, offering a pathway to more sustainable and efficient electrochemical energy conversion and storage technologies.