Highly Stable Garnet Fe₂Mo₃O₁₂ Cathode Boosts the Lithium–Air Battery Performance Featuring a Polyhedral Framework and Cationic Vacancy Concentrated Surface

Abstract

Lithium–air batteries (LABs), owing to their ultrahigh theoretical energy density, are recognized as one of the next‐generation energy storage techniques. However, it remains a tricky problem to find highly active cathode catalyst operating within ambient air. In this contribution, a highly active Fe2Mo3O12 (FeMoO) garnet cathode catalyst for LABs is reported. The experimental and theoretical analysis demonstrate that the highly stable polyhedral framework, composed of FeO octahedrons and MO tetrahedrons, provides a highly effective air catalytic activity and long‐term stability, and meanwhile keeps good structural stability. The FeMoO electrode delivers a cycle life of over 1800 h by applying a simple half‐sealed condition in ambient air. It is found that surface‐rich Fe vacancy can act as an O2 pump to accelerate the catalytic reaction. Furthermore, the FeMoO catalyst exhibits a superior catalytic capability for the decomposition of Li2CO3. H2O in the air can be regarded as the main contribution to the anode corrosion and the deterioration of LAB cells could be attributed to the formation of LiOH·H2O at the end of cycling. The present work provides in‐depth insights to understand the catalytic mechanism in air and constitutes a conceptual breakthrough in catalyst design for efficient cell structure in practical LABs.

Oxygen defect regulation, catalytic mechanism, and modification of HfO2 as a novel catalyst for lithium–oxygen batteries

“…Fluorite-structured ZrO 2 , CeO 2 , and Pr 6 O 11 exhibit good catalytic performance in Li–O 2 batteries, especially when riched in oxygen defects. 9–28 The large center space of the fluorite crystal cell benefits the adsorption and transport of oxygen. Because Hf and Zr are IVB group elements with similar atomic radii, fluorite or fluorite-like structured HfO 2 , existing in the crystal forms of tetragonal, cubic, and monoclinic, 29,30 might have comparable or better catalytic performance.…”

SDS-Assisted Hydrothermal Growth and Photocatalytic Activity of Like-Caviar MoFe₂O₄ Nanoparticle Decorated with Al₂O₃

“…MoFe 2 O 4 , a significant n-type binary metal oxide semiconductor, exhibits outstanding redox properties, catalytic activity, and chemical stability because of the modulation between octahedral (FeO 6 ) and tetrahedral (MoO 4 ) [14]. The balance between in the octahedral and tetrahedral sites may serve as a proxy for the valence distribution [15]. MoFe 2 O 4 has significant industrial uses as a catalyst [11].…”