High-Entropy Spinel Oxides with Oxygen-Rich Vacancies Improve the Catalytic Performance for Low-Temperature Flexible Zinc-Air Batteries

As a promising new energy storage device, low-temperature adaptability and slow reaction kinetics have become a restriction to flexible zinc-air batteries (FZABs) serviced in extreme environments. The research on electrocatalysts rich in oxygen vacancies (OV) to drive low-temperature FZAB performance still faces significant challenges. Developing high-entropy spinel oxides (HESOs) rich in OV is critical to improving the low-temperature FZAB performance. Herein, (FeCrCuNiMn)3O4 is synthesized using a five-metal element via a hydrothermal calcination method and loaded with three-dimensional graphene (3D-G), revealing the key role of OV in synergistically enhancing the performance of FZABs through dual active sites and interfacial charge transfer to drive electrocatalysis. The prepared electrocatalysts exhibit enhanced oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalytic activity, which drives FZABs at −25 °C, with a peak power density of up to 60.1 mW cm–2, a stable voltage gap of 0.74 V, and remarkable low-temperature cycling stability. This work effectively solves the low-temperature limitations of the FZABs by using a high-entropy strategy to improve the ORR/OER, providing a new approach for advanced green and sustainable energy conversion and storage.