Hierarchical mesoporous perovskite La_(0.5)Sr_(0.5)C_0O_(2.91) nanowires with ultrahigh capacity for Li-air batteries

摘要

Lithium-air batteries have captured worldwide attention due to their highest energy density among the chemical batteries. To provide continuous oxygen channels, here, we synthesized hierarchical mesoporous perovskite Lao.5Sra.5CoO2.91 (LSCO) nanowires. We tested the intrinsic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity in both aqueous electrolytes and nonaqueous electrolytes via rotating disk electrode (RDE) measurements and demonstrated that the hierarchical mesoporous LSCO nanowires are high-performance catalysts for the ORR with low peak-up potential and high limiting diffusion current. Furthermore, we fabricated Li-air batteries on the basis of hierarchical mesoporous LSCO nanowires and nonaqueous electrolytes, which exhibited ultrahigh capacity, ca. over 11,000 mAh-g ~1, one order of magnitude higher than that of LSCO nanoparticles. Besides, the possible reaction mechanism is proposed to explain the catalytic activity of the LSCO mesoporous nanowire.