New Progress on Bifunctional Oxygen Electrocatalysts for Li-O₂ Batteries
Recently, the research team led by Prof. Zhongshuai Wu from the Group of Two-Dimensional Materials Chemistry and Energy Applications (Group 508), State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, collaborated with the team of Academician Xinhe Bao and achieved new progress in developing efficient and stable bifunctional oxygen electrocatalysts. Taking advantage of the spatial confinement effect, this work integrates advanced Pt catalysts for oxygen reduction reaction (ORR) and RuO₂ catalysts for oxygen evolution reaction (OER) on graphene (Pt/RuO₂/G), which delivers outstanding OER/ORR performance and superior Li-O₂ battery performance.
Li-O₂ batteries have attracted tremendous attention owing to their sustainability, environmental friendliness and ultrahigh theoretical energy density up to 3500 Wh kg⁻¹. Nevertheless, Li-O₂ batteries still suffer from bottlenecks such as unsatisfactory overpotential, poor rate capability and limited cyclability, which restrict their commercialization. Therefore, exploring highly active, stable and commercially viable bifunctional oxygen electrocatalysts is critical for boosting Li-O₂ battery performance. Rational construction of bifunctional catalysts with distinct active sites to synergistically promote OER and ORR is of great significance.
In this work, the team developed a two‑dimensional porous Pt/RuO₂/G bifunctional electrocatalyst with remarkable activity and durability. The as‑prepared Pt/RuO₂/G exhibits outstanding bifunctional oxygen catalytic activity, with an OER/ORR potential gap (ΔE) of merely 0.633 V. Assembled as the cathode catalyst, the resulting Li‑O₂ battery achieves over 220 cycles (more than 2200 h) of cycling performance. Theoretical calculations reveal that the improved conductivity and weakened adsorption energy toward reaction intermediates in Pt/RuO₂/G‑based Li‑O₂ batteries contribute to low charging voltage and long‑term cyclability. For the research of high‑performance Li‑O₂ batteries, this strategy of constructing two‑dimensional ultrathin composite nanosheets provides new insights for the rational design of highly active and durable bifunctional electrocatalysts.
The relevant research was recently published in Chem Catalysis under the title “Spatially Confined Subnanometer Pt in RuO₂ Nanosheet as Robust Bifunctional Oxygen Electrocatalyst for Stabilizing Li‑O₂ Batteries” This work was financially supported by the National Natural Science Foundation of China and the Cooperative Fund of the Innovation Academy for Clean Energy, Chinese Academy of Sciences, among other projects.
(Text/Figures: Yuejiao Li)
Article link: https://doi.org/10.1016/j.checat.2023.100658