Bimetallic ZIF-derived cobalt nanoparticles anchored on N- and S-codoped porous carbon nanofibers as cathode catalyst for Li-O2 batteries

Abstract

Metal-organic frameworks (MOFs) have shown great application potential for improving Lithium-oxygen (Li-O2) batteries performance with high O2 affinity and accessible active centers. Herein, a novel type of cobalt nanoparticles embedded in porous nitrogen (N)- and sulfur (S)-codoped carbon nanofiber (Co@N/S-CNF) structure is developed by employing electrospinning technology and bimetallic zeolitic imidazole framework (ZIF-8/ZIF-67, a kind of MOF) precursor with the following annealing and hydrothermal treatment route. When utilized as cathode catalysts for Li-O2 batteries, the Co@N/S-CNF sample exhibits higher discharge capacity (9290.7 mAh g−1 at 50 mA g−1) and better cycling stability (42 cycles at 100 mA g−1 under a curtailing capacity of 500 mAh g−1) compared to Co@N-CNF electrode. The enhanced performance can be attributed to the 1D porous morphology and N/S doping effect, which can effectively improve mass transport, increase exposed active sites, and induce structural defect, thereby accelerating the formation and decomposition progress of discharge products. This simple synthetic strategy may provide a new insight for designing and developing MOFs-based multifunctional catalysts in the field of energy and electrocatalysis.