Atomically Dispersed Fe-N_(4) Sites and Fe_(3)C 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 FeN_(4) coupled with Fe_(3)C on the N-doped carbon(FeN_(4)/Fe_(3)C@NC)by one-step pyrolysis method.The FeN_(4) and Fe_(3)C 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 FeN_(4)/Fe_(3)C@NC shows a specific capacity of 1100 mA·h/g at 0.2 C(1 C=1675 mA/g).In addition,the FeN_(4)/Fe_(3)C@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.