Porous Perovskite La_0.6Sr_0.4Co_0.8Mn_0.2O₃ Nanofibers Loaded with RuO₂ Nanosheets as an Efficient and Durable Bifunctional Catalyst for Rechargeable Li–O₂ Batteries

Abstract

The design and synthesis of efficient electrocatalysts are important for electrochemical energy conversion and storage technologies. Poor electrocatalytic activities of the cathode catalysts toward both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are still two major challenges facing Li–O2 batteries. Here, we report ultralong porous perovskite La0.6Sr0.4Co0.8Mn0.2O3 nanofibers (LSCM NFs) loaded with RuO2 nanosheets (RuO2@LSCM NFs) used as a promising catalyst for Li–O2 batteries. The LSCM nanofibers were synthesized via an electrospinning technique followed by heat treatment. RuO2 nanosheets were loaded by a wet impregnation method. In comparison with that of the pristine LSCM NFs, the cell with RuO2@LSCM NFs catalyst exhibits good performances toward the ORR and OER with a higher specific discharge capacity (12741.7 mA h g–1), improved cyclability, and rate capability as well as low voltage gap. Moreover, the results of LSV indicate that LSCM NFs can efficiently catalyze the decomposition of the reaction side product Li2CO3 while RuO2@LSCM NFs are capable of decomposing LiOH. The enhanced cell performances are attributed to the merits of high catalytic activity and the porous structure of the RuO2@LSCM NF catalyst.