Synthesis of Perovskite‐Based Porous La0.75Sr0.25MnO3 Nanotubes as a Highly Efficient Electrocatalyst for Rechargeable Lithium–Oxygen Batteries

TLDR: A facile, effective, and scalable strategy for preparing perovskite-based porous La0.75Sr0.25MnO3 nanotubes (PNT-LSM) by combining the electrospinning technique with a heating method is proposed and realized.

Abstract: Rechargeable lithium–oxygen (Li-O2) batteries have recently attracted great attention because they can theoretically store 5–10 times more energy than current lithium-ion batteries, which is essential for clean energy storage, electric vehicles, and other high-energy applications. However, to use Li-O2 batteries for practical applications, numerous scientific and technical challenges need to be surmounted. 8] In response, intensive research efforts have been made to address the challenges by incorporating metal oxides, metal nitrides, metal nanoparticles, 21] and organometallic compounds 22] as electrocatalysts in the O2 electrode. Although significant improvements in the oxygen-reductionreaction (ORR) and/or oxygen-evolution-reaction (OER) overpotentials have been achieved, there is still a demand for highly efficient electrocatalysts to further enhance the specific capacity, rate capability, and cyclic life especially at a high capacity. On the other hand, most of the catalyst performances reported thus far are tested using carbonate-based or mixed ether-carbonate-based electrolytes, which have now been shown to be not inert to the superoxide radical (O2C ) and thus are inevitably decomposed upon cell discharge/ charge. For example, Luntz and co-workers demonstrate that, when carbonate-based electrolytes are employed for LiO2 cells, the main role of the Au, Pt, and MnO2 catalysts is to catalyze the decomposition of the electrolytes. In this context, the development of OER and ORR electrocatalysts in a relatively stable electrolyte is thus of importance to realize a reversible Li-O2 battery. Compared to carbonate, ether-based electrolytes have been reported to be more suitable for Li-O2 batteries because the desired lithium peroxide is the dominant product. 29] However, there are not many reports on electrocatalysts for Li-O2 batteries with ether-based electrolytes. 10, 30, 33] Perovskite oxides have a high electronic/ionic conductivity and catalytic activity and thus could be a promising candidate as electrocatalyst for Li-O2 batteries. [33–35] Herein, we firstly propose and realize a facile, effective, and scalable strategy for preparing perovskite-based porous La0.75Sr0.25MnO3 nanotubes (PNT-LSM) by combining the electrospinning technique with a heating method. Figure 1