Pomegranate-like C₆₀@cobalt/nitrogen-codoped porous carbon for high-performance oxygen reduction reaction and lithium-sulfur battery

Porous carbon materials play essential roles in electrocatalysis and electrochemical energy storage. It is of significant importance to rationally design and tune their porous structure and active sites for achieving high electrochemical activity and stability. Herein, we develop a novel approach to tune the morphology of porous carbon materials (PCM) by embedding fullerene C₆₀, achieving improved performance of oxygen reduction reaction (ORR) and lithium-sulfur (Li-S) battery. Owing to the strong interaction between C₆₀ and imidazole moieties, pomegranate-like hybrid of C₆₀-embedded zeolitic imidazolate framework (ZIF-67) precursor is synthesized, which is further pyrolyzed to form C₆₀-embedded cobalt/nitrogen-codoped porous carbon materials (abbreviated as C₆₀@Co-N-PCM). Remarkably, the unique structure of C₆₀@Co-N-PCM offers excellent ORR electrocatalytic activity and stability in alkaline solutions, outperforming the commercial Pt/C (20 wt.%) catalyst. Besides, C₆₀@Co-N-PCM as a novel cathode delivers a high specific capacity of ~ 900 mAh·g^-1 at 0.2 C rate in Li-S batteries, which is superior to the pristine ZIF-67-derived PCM without embedding C₆₀.