Co/Mon Invigorated Bilateral Kinetics Modulation for Advanced Lithium-Sulfur Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-sulfur (Li-S) batteries face challenges from sluggish sulfur redox kinetics and lithium dendrite growth.
• Separator modification offers a dual approach to mitigate these issues.

Purpose of the Study:

• To design and apply a Co/MoN composite as a separator modifier for Li-S batteries.
• To address electrochemical kinetics at both the sulfur cathode and lithium anode.

Main Methods:

• Rational design of a Co/MoN composite for separator decoration (Co/MoN@PP).
• Investigation of adsorption-catalysis function for polysulfide inhibition and Li+ flux enhancement.
• Performance evaluation including discharge capacity, decay rate, and cycling stability.
• In-situ Raman spectroscopy and theoretical calculations to evidence kinetics.

Main Results:

• Co/MoN@PP separators effectively inhibited polysulfide shuttle and accelerated electrochemical conversion.
• Enhanced Li+ flux facilitated uniform lithium plating and stripping.
• Achieved high initial discharge capacity (1570 mAh g-1 at 0.2 C) with a low decay rate (0.39%).
• Demonstrated stable cycling over 800 h with uniform Li+ transportation and high areal capacity (4.62 mAh cm-2) at high mass loadings.

Conclusions:

• The Co/MoN composite separator provides a synergistic effect for multifunctional microdomains.
• This strategy effectively solves issues with Li anodes and S cathodes for long-cycling Li-S batteries.