Selective and Bifunctional Catalytic Electrochemical Conversion of Organosulfide Molecule by High‐Entropy Carbides.

Yang, Wanlin; Xu, Tongmin; Yang, Chengkai; Fan, Huarong; Sun, Wenxuan; Ma, Xinfeng; Wang, Xin; Fu, Yongzhu

The development of high energy density Li‐organosulfur batteries is severely hampered by the slow redox kinetics and the shuttle effect of polysulfides. Reasonably designing new electrocatalysts to accelerate the electrochemical conversion of various intermediates is an effective strategy to overcome the above challenges. Specifically, high entropy metal carbides/nanofibers (Mn0.25Co0.25Ni0.25Cu0.25Fe2)C/CNFs (HEC/CNFs) are prepared by electrospinning method and applied in lithium‐phenyl tetrasulfide (Li‐PTS) batteries. The HEC composition, featuring multiple randomly dispersed metal elements, modulates its d‐band structure and expedites the redox reaction for polysulfides. Therefore, HEC as a bidirectional catalyst reduces the activation energy of the redox reaction and selectively regulates the improvement of the generation and decomposition of inorganic intermediates during the charge–discharge process. The HEC/CNFs/PTS electrodes have an initial theoretical specific capacity of 527 mAh g−1 at 0.5 C, with a slow capacity decay rate of 0.078% per cycle, exceeding 500 cycles. More importantly, it can also maintain a theoretical specific capacity of 450 mAh g−1 under high surface loading conditions (PTS ≈ 4.8 mg cm−2) when applied to Li‐organosulfur pouch cells. This work demonstrates the bidirectional catalytic effect of HEC in Li‐PTS batteries and presents pathways for energy storage and conversion in various high entropy carbide materials.

CARBON nanofibers; CATALYSIS; OXIDATION-reduction reaction; ENERGY development; ENERGY density; LITHIUM sulfur batteries

Advanced Functional Materials, 2024, Vol 34, Issue 49, p1

1616-301X

Academic Journal

10.1002/adfm.202409450