Superior oxygen electrocatalyst derived from metal organic coordination polymers by instantaneous nucleation and epitaxial growth for rechargeable Li-O-2 battery

Rechargeable aprotic Li-O-2 batteries have attracted increasing attention due to their extremely high capacity, and it is very important to design appropriate strategies to synthesize efficient catalysts used as oxygen cathode. In present work, we present an expedient "instantaneous nucleation and epitaxial growth" (INEG) synthesis strategy for convenient and large-scale synthesis of ultrafine MOCPs nanoparticles (size 50-100 nm) with obvious advantages such as fast synthesis, high yields, low costs and reduced synthetic steps. The bimetallic Ru/Co-MOCPs are further pyrolyzed to obtain bimetallic Co and low content of Ru-based nanoparticles embedded within nitrogen-doped carbon (Ru/Co@NAC) as an efficient catalyst used in Li-O-2 battery. The Ru/Co@NAC provides porous carbon framework for the ion transportation and O-2 diffusion, and has large amounts of metal/nonmetal sites as active site to promote the oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) in Li-O-2 batteries. As a consequence, a high discharge specific capacity of 15246 mA h g(-1) at 250 mA g(-1), excellent rate capability at different current densities, and stable overpotential during cycling, are achieved. This work opened up a new understanding for the industrialized synthesis of ultrafine catalysts for Li-O-2 batteries with excellent structural characteristics and electrochemical performance. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.