Conductive FeOOH as Multifunctional Interlayer for Superior Lithium-Sulfur Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Commercialization of lithium-sulfur batteries (LSBs) is hindered by low conductivity, volume changes, and the polysulfide shuttle effect.
• Existing solutions often fail to adequately address these multifaceted challenges in LSBs.

Purpose of the Study:

• To design a conductive FeOOH interlayer as a catalyst and trapper for lithium polysulfides (LiPSs) in LSBs.
• To investigate the mechanism by which FeOOH enhances LiPSs conversion and overall battery performance.

Main Methods:

• Fabrication of a conductive FeOOH nanorod interlayer.
• Characterization of FeOOH's interaction with sulfur and LiPSs, including Lewis acid site analysis.
• Electrochemical testing of LSBs with the FeOOH interlayer, evaluating capacity, rate capability, and cycling stability.

Main Results:

• FeOOH exhibits strong affinity for sulfur and LiPSs, acting as an effective chemical anchor.
• The FeOOH interlayer significantly accelerates LiPSs conversion kinetics and improves Li2S oxidation.
• LSBs with FeOOH demonstrated a high discharge capacity (1449 mAh g-1 at 0.05 C), low decay (0.05% per cycle at 1 C), and excellent rate capability (449 mAh g-1 at 2 C).

Conclusions:

• The multifunctional FeOOH interlayer effectively mitigates key issues in LSBs by chemisorbing LiPSs and enhancing redox kinetics.
• This approach offers a promising strategy for developing high-performance and stable lithium-sulfur batteries.