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Fe3O4@Fe Core–Shell Okara-Derived Activated Carbon for Superior Polysulfide Control in Lithium–Sulfur Batteries

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Lithium–sulfur (Li–S) batteries offer high energy density but suffer from a polysulfide shuttle effect, leading to capacity fading and poor cycling stability. To address this, the Fe 3 O 4 @Fe core–shell Okara-derived activated carbon (Fe 3 O 4 @Fe-AC) using a sustainable and scalable approach with okara, a soybean residue, as the carbon precursor was developed. Electrochemical tests demonstrate that Fe 3 O 4 @Fe-AC/S cathodes exhibit superior cyclic stability, achieving an initial discharge capacity of 755 mAh/g at 0.5C and retaining 572 mAh/g after 500 cycles, with an ultralow capacity decay rate of 0.050% per cycle. At a high rate of 3C, the battery delivers an initial capacity of 557 mAh/g and retains a capacity of 367 mAh/g after 500 cycles, highlighting its excellent rate performance and low polarization potential. This composite enhances battery performance by integrating high-surface-area activated carbon for physical polysulfide adsorption, Fe 3 O 4 for dipole–dipole interactions, and metallic Fe for catalytic LiPS conversion. With its high electrochemical performance, cost-effective synthesis, and sustainable precursor, Fe 3 O 4 @Fe-AC represents a promising material for practical Li–S battery applications.

Source: The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5c02606