Recent Advances in Carbon‐Based Bifunctional Oxygen Catalysts for Zinc‐Air Batteries

Abstract

air batteries (ZABs) have recently received tremendous research attention due to their high theoretical energy densities. However, current ZABs suffer from poor energy efficiency and cyclability, mainly owing to the sluggish kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) on the air electrode. Therefore, rational design of efficient bifunctional oxygen electrocatalysts with high activity and stability is essential for improving battery performance. Carbon-based nanomaterials are promising candidates for bifunctional oxygen catalysis. In this review, we present the latest development of carbon-based bifunctional electrocatalysts for ZABs. Firstly, the related reaction mechanisms of bifunctional ORR/OER catalysts are introduced. Then, the recent advances in developing carbon-based bifunctional catalysts with tailored structure and promising catalytic performance are introduced following the regulation strategies, e. g., heteroatom doping, defect engineering, and/or hybridizing with other active materials. Finally, the key challenges and perspectives of advanced ZABs are provided to better shed light on future research. . This review aims to provide timely information of the carbon-based bifunctional oxygen catalysts for researchers and to shed light on the future development of high-performance catalysts and ZABs. 2 3 4 5 6 7 8

Discharge profile of a zinc-air flow battery at various electrolyte flow rates and discharge currents

“…In fact, as potential alternatives for lithium-ion batteries (LIBs), zinc-air batteries (ZABs) are highly regarded. ZABs offer high theoretical energy density of 1086 Wh/kg (including oxygen) and 1350 Wh/kg (excluding oxygen) which is five times higher than that of current LIBs [3][4][5] . Furthermore, ZABs have a simple design, low operational temperature, high efficiency, high safety and are environmentally friendly 6,7 .…”

2D Nitrogen‐Doped Carbon Nanotubes/Graphene Hybrid as Bifunctional Oxygen Electrocatalyst for Long‐Life Rechargeable Zn–Air Batteries

“…Zn–air battery generates electrical energy through the redox reaction of metal at anode and oxygen at the cathode . However, their large‐scale applications are hindered by low power density and poor stability, caused by sluggish oxygen reduction reaction (ORR) for the discharging and oxygen evolution reaction (OER) for the charging process . Not only the scarcity and high‐cost of precious metal‐based electrocatalysts are the significant concerns, such as Pt/C for ORR and IrO x /RuO x for OER, but their insufficient catalytic bifunctionality and inferior durability are also the short‐slab .…”

Flexible and Wearable Power Sources for Next‐Generation Wearable Electronics

“…Interested readers may refer to the previously reported studies. [123][124][125][126][127][128] As for the specific flexible and wearable metalÀ air batteries, air electrodes are required to meet the characteristics of high porosity to promote the diffusion of oxygen and large surface area to promote ORR and OER on active sites. 3D carbon fiber materials such as carbon fiber paper, carbon cloth, and carbon felt are widely used as current collectors for air electrodes in metalÀ air batteries due to their unique porous networks, high electrical conductivity, and good mechanical stability.…”