Atomically Dispersed Fe-N4 Sites and Fe3C Particles Catalyzing Polysulfides Conversion in Li-S Batteries

Lithium-sulfur(Li-S) batteries have been puzzled by the shuttle effect. In the recent years, catalytic materials present a huge potential for solving this problem. However, the exploitation for catalytic activity was still challenging in Li-S batteries. In this article, we put forward a single atom catalyst (SAC) of FeN4 coupled with Fe3C on the N-doped carbon (FeN4/Fe3C@NC) by one-step pyrolysis method. The FeN4 and Fe3C synergistically catalyze the polysulfides conversion when the N-doped carbon provides the high conductive three-dimensional skeleton in Li-S batteries. As a result, the FeN4/Fe3C@NC shows a specific capacity of 1100 mA.h/g at 0.2 C(1 C=1675 mA/g). In addition, the FeN4/Fe3C@NC maintains 99.01% of the pristine specific capacity after 100 cycles at 0.5 C, indicating the improved electrochemical performance in Li-S batteries. This work sheds new lights on the design of engineering catalysts for developing high-performance Li-S batteries.

Automated summary

In this study, a single atom catalyst FeN4/Fe3C@NC was prepared by one-step pyrolysis method and its catalytic effect in Li-S batteries was investigated. The FeN4 and Fe3C synergistically catalyze the polysulfides conversion and the N-doped carbon provides a highly conductive three-dimensional skeleton, significantly improving the electrochemical performance of Li-S batteries.