Tailored combination of low dimensional catalysts for efficient oxygen reduction and evolution in Li-O₂ batteries

The development of efficient bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reac-tion (OER) is a key issue pertaining high performance Li-O₂ batteries. Here, we propose a heterogeneous electrocatalyst consisting of LaMnO₃ nanofibers (NFs) functionalized with RuO2 nanoparticles (NPs) and non-oxidized graphene nano-flakes (GNFs). The Li-O₂ cell employing the tailored catalysts delivers an excellent electrochemical performance, affording significantly reduced discharge/charge voltage gaps (1.0 V at 400 mAg^-1), and superior cyclability for over 320 cycles. The outstanding performance arises from (1)the networked LaMnO₃ NFs providing ORR/OER sites without severe aggrega-tion, (2) the synergistic coupling of RuO₂ NPs for further improving the OER activity and the electrical conductivity on the surface of the LaMnO₃ NFs, and (3) the use of GNFs providing a fast electronic pathway as well as improved ORR kinetics.