Wood fiber tailored Fe-O-C heterostructure to accelerate polysulfides conversion for lithium–sulfur batteries

Lithium-sulfur (Li-S) batteries are promising alternatives for the forthcoming generation of power and energy storage batteries due to their remarkable features and advantages. However, the large-scale application of Li-S batteries faces significant challenges posed by the shuttle effect of lithium polysulfides (LiPSs) and sluggish reaction kinetics of sulfur cathode. Herein, a low-priced Fe2O3/CFe15.1/Fe heterostructure was purposefully engineered and distributed within carbonized wood fibers (CWF) by a straightforward hydrothermal and pyrolysis process. The distinctive Fe2O3/CFe15.1/Fe heterostructure concurrently achieves both chemical adsorption and catalytic capability for LiPSs, effectively mitigating the shuttle effect. The optimized Fe2O3/CFe15.1/Fe heterostructure exhibits impressive electrochemical performance with a high initial capacity of 1174.7 mA h g−1 at 0.1 C, an outstanding rate capacity of 687.4 mA h g−1 at 2.0 C, and a remarkable cycling stability, maintaining a notable capacity of 513.6 mA h g−1 after 1000 cycles at 1.0 C. This work presents a viable strategy of a multifunctional Fe2O3/CFe15.1/Fe heterostructure to capture and expedite the transformation of LiPSs, realizing exceptional electrochemical performance.