Porous FeCo Glassy Alloy as Bifunctional Support for High‐Performance Zn‐Air Battery

Abstract

The Zn‐air battery (ZAB) is attracting increasing attention due to its high safety and preeminent performance. However, the practical application of ZAB relies heavily on developing durable support materials to replace conventional carbon supports which have unrecoverable corrosion issues, severely jeopardizing ZAB performance. Herein, a novel porous FeCo glassy alloy is developed as a bifunctional catalytic support for ZAB. The conducting skeleton of the porous glassy alloy is used to stabilize oxygen reduction cocatalysts, and more importantly, the FeCo serves as the primary phase for oxygen evolution. To demonstrate the concept of catalytic glassy alloy support, ultrasmall Pd nanoparticles are anchored, as oxygen reduction active sites, on the porous FeCo (noted as Pd/FeCo) for ZAB. The Pd/FeCo exhibits a significantly improved electrocatalytic activity for oxygen reduction (a half‐wave potential of 0.85 V) and oxygen evolution (a potential of 1.55 V to reach 10 mA cm−2) in the alkaline media. When used in the ZAB, the Pd/FeCo delivers an output power density of 117 mW cm−2 and outstanding cycling stability for over 200 h (400 cycles), surpassing the conventional carbon‐supported Pt/C+IrO2 catalysts. Such an integrated design that combines highly active components with a porous architecture provides a new strategy to develop novel nanostructured electrocatalysts.

Anodic Transformation of a Core‐Shell Prussian Blue Analogue to a Bifunctional Electrocatalyst for Water Splitting

“…[34,35] Notably, an additional peak at 531.9 eV emerged after 5 min activation, the peak was attributed to hydroxyl groups, while the peak of adsorbed oxygen species disappeared, this is because the conversion from PBA to Ni(OH) 2 requires the consumption of the adsorbed oxygen on the sample surface. [36] On increasing the anodization time to 10 min, another peak appears at 533.3 eV corresponding to oxygen vacancies and defects created during the anodization process. The Ni 2p edge peaks (Figure 3f) of NiCo@A-NiCo-PBA found at 855.7 and 873.2 eV were assigned to 2p 3/2 and 2p 1/2 spins of Ni 2+ , and the two peaks at 856.9 and 874.3 eV were attributed to 2p 3/2 and 2p 1/2 spins of Ni 3+ , indicating the co-existence of Ni 2+ and Ni 3+ in NiCo@A-NiCo-PBA.…”

Revealing the effects of conductive carbon materials on the cycling stability of rechargeable Zn‐air batteries

“…For example, Li et al designed a novel Co species/N‐doped carbon electrocatalysts, exhibiting a high onset potential −0.12 V (vs SCE) and long‐term stability in the alkaline situation 23 . Fu et al developed a novel porous FeCo glassy alloy as the bifunctional catalytic support 24 . Ultrasmall Pd nanoparticles are anchored as oxygen reduction active sites, delivering an output power density of 117 mW cm −2 and outstanding cycling stability for over 200 hours.…”

“…23 Fu et al developed a novel porous FeCo glassy alloy as the bifunctional catalytic support. 24 Ultrasmall Pd nanoparticles are anchored as oxygen reduction active sites, delivering an output power density of 117 mW cm À2 and outstanding cycling stability for over 200 hours. Chen et al decorated Co 3 O 4 on the surface of N-doped carbon nanotubes (CNTs) as bifunctional electrocatalysts for RZABs, which resulted in superior OER and ORR catalytic activity and long cycle life of over 100 hours at 20 mA cm À2 .…”

Ultrathin Co(OH)2 Nanosheets@Nitrogen‐Doped Carbon Nanoflake Arrays as Efficient Air Cathodes for Rechargeable Zn–Air Batteries

“…The enlarged working life and the reduced charging voltage can be attributed to the composite structure of Co(OH) 2 @NC, wherein the outer Co(OH) 2 acts as an active shield for not only promoting the charging process, but also preventing the inner NC from irreversible corrosion at high potentials. [ 57 ]…”