Transition metal/carbon hybrids for oxygen electrocatalysis in rechargeable zinc‐air batteries

Abstract

Zinc‐air batteries (ZABs) could be an ideal candidate for challenging energy conversion and storage technology. Usually, the crucial oxygen reduction reaction and oxygen evolution reaction are naturally lethargic and require efficient catalysts to kinetically boost the energy conversion processes to achieve the practicable ZABs application. Transition‐metal/carbon hybrid catalysts show excellent potentials in electrocatalysis, and they have been developed into cost‐effective and scalable oxygen electrocatalyst alternatives for expensive and scarcer noble metal ones in rechargeable ZABs. Herein we summarize recent achievements in transition metal/carbon hybrids for oxygen electrocatalysis. These catalysts mainly fall into two categories by the integrated metal/metal oxides nanoparticles and atomically dispersed transition metal/carbon matrix. We focus on the relationship between structure and performance with their synthesis strategies. Their application in rechargeable ZABs are also comprehensively discussed. Finally, the perspectives on transition metal/carbon hybrids for oxygen electrocatalysis are presented for the future challenges in rechargeable ZABs.

Recent Advances on MOF Derivatives for Non-Noble Metal Oxygen Electrocatalysts in Zinc-Air Batteries

“…At present, there are two main points of view to explain the reaction mechanism of OER, namely: (1) directly combine two M–O to generate O 2 ; (2) first generate M-OOH, and then generate O 2 to from M-OOH, here M means active site. Compared with the ORR, the OER kinetics of rechargeable ZABs are much slower, a charging voltage of about 2.0 V or higher is often required, and the open-circuit voltage of the discharging process is generally around 1.2 V. Furthermore, the excessive charging voltage will cause the corrosion of air electrode and oxidation of the electrocatalyst [ 29 ]. Certainly, the existing three-electrode structure allows a rechargeable zinc-air battery to be assembled using two single functional oxygen electrocatalysts to achieve dual functions.…”

“…Hence, alternate electrochemical energy storage devices [ 5 ], such as fuel cells [ 6 – 11 ], lithium-ion batteries [ 12 , 13 ], solar cells [ 14 , 15 ], supercapacitors [ 16 – 18 ] and metal-air batteries [ 19 – 26 ] have been widely explored. Among these renewable sources, zinc-air batteries have attracted great attention due to their high specific energy density, environmental friendliness and safety [ 27 – 29 ]. Zinc-air batteries possess second highest weight-specific energy after the Li-air batteries, while the volume-specific energy is the highest among the other renewable energy sources (Fig.…”

Recent Advances on Electrospun Nanomaterials for Zinc–Air Batteries

“…Many reports have been devoted to the exploration of integrating metal‐based catalysts in the electrospun carbon nanofibers, which can be attribute to the advantages in low cost, a wide range of potential candidates, and excellent thermal stability of metal catalysts. [ 78–81 ] Currently, intensive research efforts are focusing on how to obtain metal‐based catalysts materials by combining polymers and metals through electrospinning and subsequent processing. For instance, the multimetallic particles on the nanofibers can provide more active sites, adjust the electronic state around the carbon atoms, and improve the oxygen catalytic activity.…”

Constructing nano‐channeled tin layer on metal zinc for high‐performance zinc‐ion batteries anode

“…Throughout the history of world development, every technological advancement, and social productivity leap are closely related to energy issues 1,2 . At the same time, new requirements are also put forward for energy conversion and storage technology 3–6 . Due to their green and safe features, rechargeable aqueous metal‐ion batteries show high promise as alternative energy storage devices 7 .…”