Iron atom-nanoparticles for interactional enhancing the electrocatalytic reaction activity in Li-S batteries

The undesirable shuttle effect and sluggish redox kinetics of polysulfides seriously result in low sulfur utilization and poor capacity retention. Here, an integrated strategy is proposed by rational designing multifunctional architecture to manipulate the redox kinetics of polysulfides, specifically, by employing iron atoms (Fe-As) and iron-species nanoparticles (Fe-NPs) co-embedded nitrogen-doped carbon nanotube (Fe-NCNT) as catalyst and host for sulfur. The synergistic cooperation of Fe-As and Fe-NPs provides efficient active sites to facilitate the diffusion, strengthen the affinities, and promote the conversion reactions for polysulfides. Furthermore, the NCNT not only offers practical Li+ transport pathways but also immobilize the polysulfides effectively. Benefiting from these merits, the Fe-NCNT/S electrodes exhibit high initial specific capacity of 1502.6 mAh/g at 0.1 C, outstanding rate performance (830 mAh/g at 2 C), and good cycling performance (597.8 mAh/g after 500 cycles with an ultralow capacity fading rate of 0.069% per cycle). This work features the distinct interaction of iron atom-nanoparticles on facilitating immobilization-diffusion-transformation process of polysulfides, and it also expected to pave the way for the application in practical Li-S batteries. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

By rational designing a multifunctional architecture using iron atoms and iron nanoparticles embedded in carbon nanotubes, the redox kinetics of polysulfides can be manipulated to improve sulfur utilization and capacity retention in Li-S batteries.