Synergistic Control of Structural Disorder and Surface Bonding Nature to Optimize the Functionality of Manganese Oxide as an Electrocatalyst and a Cathode for Li–O₂ Batteries

Abstract

In article number 1903265, Yong‐Mook Kang, Seong‐Ju Hwang, and co‐workers develop an efficient way to improve the electrocatalyst and Li–O2 battery performances of metal oxide via synergistic control of structural disorder and surface bonding nature. The amorphization and iodate anchoring are quite effective in improving electrocatalyst/electrode functionalities of δ‐MnO2 via the alteration of surface bonding character, the stabilization of Mn3+ species, and the enhanced charge transfer of interfaces.

In Situ Defect Engineering Route to Optimize the Cationic Redox Activity of Layered Double Hydroxide Nanosheet via Strong Electronic Coupling with Holey Substrate

“…The weakening of (Fe−O) bond distance upon hybridization with holey TiN NTs provides appropriate strength of interaction with OH − , which is beneficial for electrochemically activating the Fe ions and improving electrocatalyst activity for OER. [39] The present in situ SERS spectroscopic results indicate holey TiN NTs with nitrogen vacancies can act as efficient hybridization matrix for electrocatalyst material with strong interfacial interaction and facial charge transfer, therefore verifying the usefulness of the hybridization strategy for controlling the defect structure of inorganic solids and enhancing their electrocatalytic redox activity. The strong interfacial interaction of LDH and holey TiN was further confirmed by the photoluminescence (PL) results, whereby a weaker PL intensity was observed for the holey-TiN−LDH-2 compared to the non-holey-TiN−LDH-2, as shown in Figure 6g.…”

“…The increase in the Ni/Fe−O bond distances can facilitate the attachment of reactant OH − species onto the LDH component, which is beneficial for promoting the occupation of both Fe and Ni ions of hybridized LDH species in the OER process. [ 39 ] (4) As evidenced by EIS analysis, an efficient electronic coupling with conductive TiN NTs enhances the electrical conductivity and charge transfer kinetics of Ni−Fe‐LDH, which is also responsible for the improved electrochemical performance and redox activity of TiN−LDH.…”

Oxygen Vacancy-Rich RuO2–Co3O4 Nanohybrids as Improved Electrocatalysts for Li–O2 Batteries

“…Metal oxides are usually good electrocatalysts for Li–O 2 batteries, which have been proposed and widely investigated. − Among these metal oxides, Co 3 O 4 shows favorable catalytic activity in the process of OER, and many methods have been developed in recent years to further enhance its catalytic activity. − Increasing oxygen vacancy and adjusting electron structure are effective strategies to enhance its activitsy. − The oxidation state of Co in Co 3 O 4 is between Co 2+ and Co 3+ , which not only produces a reversible surface oxygen ion exchange but also provides opportunity for electron interaction with other oxides. − In addition, the structure of the electrocatalyst also plays an important role in its electrochemical performance because the insoluble discharge products can coat on the surface of the catalyst, resulting in the termination of the cycle. The hollow structure with a large specific surface area can provide enough storage place for the accumulation of discharge products, while ensuring enough transmission channels for oxygen and the electrolyte. ,,, Combined with the abovementioned data, rational design of composite oxide with oxygen vacancies to tune the electron structure while optimizing the structure to provide sufficient space is of great importance but is still a challenge.…”

The synergistically enhanced activity and stability of layered manganese oxide via the engineering of defects and K+ ions for oxygen electrocatalysis

“…11 The third type, which are trapped in crystal lattices, are denoted as lattice oxygen species (O lat ), whose electrochemical activity is generally far from satisfactory. 46 O spectra are given in Fig. 4df and h, and they can be deconvolved into three peaks at 533.1, 530.9, and 529.…”