Engineering the Electronic Interaction between Atomically Dispersed Fe and RuO₂ Attaining High Catalytic Activity and Durability Catalyst for Li‐O₂ Battery

Abstract

It is significant to develop catalysts with high catalytic activity and durability to improve the electrochemical performances of lithium‐oxygen batteries (LOBs). While electronic metal‐support interaction (EMSI) between metal atoms and support has shown great potential in catalytic field. Hence, to effectively improve the electrochemical performance of LOBs, atomically dispersed Fe modified RuO2 nanoparticles are designed to be loaded on hierarchical porous carbon shells (FeSA‐RuO2/HPCS) based on EMSI criterion. It is revealed that the Ru‐O‐Fe1 structure is formed between the atomically dispersed Fe atoms and the surrounding Ru sites through electron interaction, and this structure could act as the ultra‐high activity driving force center of oxygen reduction/evolution reaction (ORR/OER). Specifically, the Ru‐O‐Fe1 structure enhances the reaction kinetics of ORR to a certain extent, and optimizes the morphology of discharge products by reducing the adsorption energy of catalyst for O2 and LiO2; while during the OER process, the Ru‐O‐Fe1 structure not only greatly enhances the reaction kinetics of OER, but also catalyzes the efficient decomposition of the discharge products Li2O2 by the favorable electron transfer between the active sites and the discharge products. Hence, LOBs based on FeSA‐RuO2/HPCS cathodes show an ultra‐low over‐potential, high discharge capacity and superior durability.

Catalytic Performance of Amorphous and Crystalline RuO2 Loading on TiO2 Nanosheets in Lithium–Oxygen Batteries

“…To further probe the surface structure of the a/c-RuO 2 /TiO 2 electrodes, ex situ XPS techniques are further carried out. The high-resolution Li 1s XPS spectra of a/c-RuO 2 /TiO 2 electrodes (Figure b and c) can be deconvoluted into two Li–O vibrations around 56.01 and 55.4 eV, corresponding to amorphous Li 2‑ x O 2 and crystalline Li 2 O 2 , respectively. ,, The proportion of Li 2‑ x O 2 in Li 1s XPS spectra of a-RuO 2 /TiO 2 is higher than that of c-RuO 2 /TiO 2 . Previous studies have shown that the amorphous discharge product (Li 2‑ x O 2 ) decomposes more easily than the crystalline discharged product (Li 2 O 2 ) during the OER process. ,,, As shown in Figure d and e, electrochemical impedance spectroscopy (EIS) was employed to investigate the cathodes at different discharged and charged states.…”

“…74-0115). In contrast, the discharged a-RuO 2 /TiO 2 shows two weak peaks at 32.8° and 34.9°, indicating the formation of Li 2 O 2 with poor crystallinity. , After the full charging process, the peaks associated with Li 2 O 2 completely disappear in the a-RuO 2 /TiO 2 cathode. By contrast, the related Li 2 O 2 peaks did not disappear fully in the c-RuO 2 /TiO 2 cathode, which is consistent with SEM observation.…”

Asymmetric Catalytic Site Driving LiOH Chemistry for Li–O2 Batteries Based on Cationic Vacancy-Derived Single-Atom Spinel

“…It is noteworthy that in AC-HAADF-STEM images, the brightness of different species is directly proportional to the square of their relative atomic mass. 42 In Ru SA -MCO, Ru has a larger relative atomic mass compared to Mn and Co, thus appearing as bright spots (highlighted by yellow circles) (Figure 1e−g). The bright spots of Ru atoms are uniformly dispersed on the MCO substrate, indicating the preliminary inference that Ru may exist in the form of single atoms.…”

A Grafted Hybrid Nanosheet Array Architecture Enables Efficient Bifunctional Oxygen Catalytic Electrodes for Rechargeable Lithium−Oxygen Batteries

“…[3,4] Efficient DOI: 10.1002/adsu.202300510 bifunctional catalytic cathodes are highly desired to facilitate both the ORR and the OER, thereby achieving the high practical energy densities of Li−O 2 batteries. [5] So far, single-component catalytic materials that have intrinsic bifunctional ORR and OER catalytic activities are limited to ruthenium oxides, [6,7] perovskites, [8] etc. To this end, combinatorial strategies integrating the catalytic activities of different components were proposed to prepare more alternative bifunctional catalysts.…”