Single‐Atom‐Mediated Spinel Octahedral Structures for Elevated Performances of Li‐Oxygen Batteries

Abstract

Li‐oxygen batteries have attracted much attention due to its ultra‐high theoretical specific capacity, but the discharge product Li2O2 is easy to accumulate, leading to low battery stability. Here, we demonstrate a series of high‐efficiency cathode catalysts of Co3O4 loaded with single‐atomic metals (M=Ru, Pd, Pt, Au, Ir). The single‐atomic metal could substitute the central Co atom in the octahedral coordination structure and maintain the structural stability; benefiting from the electron promoter effect, rendering more highly active Co3+ exposed, providing rich nucleation sites for Li2O2 deposition. And the loaded M atoms could separate the active Co3+ centers, thereby regulating the dispersion of Li2O2 to obtained a sheet‐like morphology, which could facilitate its decomposition in the subsequent charge cycle. Our work found that the single atoms could effectively modulate the active metal oxide with which it is coordinated, thus collectively boosting the catalytic performance.

Ce Single-Atom Incorporation Enhances the Oxygen Evolution Reaction of Co3O4 in Acid

“…The redox conversion of Ce 3+ /Ce 4+ can effectively promote the rapid diffusion of oxygen and the kinetics of oxygen released in the lattice; thus, Ce doping promotes electronic interactions. 30,31 High-resolution Co 2p XPS spectrum shows two main spin-orbit peaks attributed to Co 2p 3/2 and Co 2p 1/2 (Figure 2c), respectively, and it clearly shows that the orbital peaks of Co 2p and O 1s were negatively shifted and the binding energy was reduced compared with Co 3 O 4 . Additionally, a lower ratio of Co 3+ and a higher ratio of Co 2+ could be seen, and specifically, the ratio of Co 2+ to Co 3+ in Co 3 O 4 and Ce-Co 3 O 4 increased from 1.84 to 1.91.…”

Tailoring Li2CO3 configuration and orbital structure of CoS to improve catalytic activity and stability for Li‐CO2 batteries

“…Then at state 3, Li 2 CO 3 on both cathodes becomes larger and partially decomposes at state 4 in the same position as state 2. The desirable distribution on the plane has a larger contact area between Li 2 CO 3 and catalysts than on the edge, which contributes to charge transfer in Li 2 CO 3 decomposition 18–20 . Therefore, S V ‐CoS effectively reduces the overpotential during charge.…”

Nanoengineering of Cathode Catalysts for Li–O2 Batteries

“…Compared to conventional catalysts in Li–O 2 batteries, single-atom electrocatalysts have gained significant attention owing to their unqiue electronic structure, precisely tunable coordination configuration, and superior stability. ,, Similar to the electrocatalytic processes of OER and CO 2 reduction, the electronic structure of single atoms in Li–O 2 batteries can be tuned by controlling their coordination structures and environment. , Single-atom catalysts exhibit the highest atomic utilization efficiency (100%), while traditional electrocatalysts exist as nanoparticles, with only surface atoms available for Li–O 2 batteries. Consequently, the catalytic activity by each single atom in soild electrocatalysts is inferior to that of single-atom catalysts.…”