Stabilizing cathode structure via the binder material with high resilience for lithium-sulfur batteries

Area of Science:

• Energy Storage
• Materials Science
• Electrochemistry

Background:

• Lithium-sulfur (Li-S) batteries offer high energy density but face challenges with sulfur cathode volumetric changes.
• Binder selection is crucial for maintaining cathode structural integrity and battery performance.

Purpose of the Study:

• To synthesize and evaluate a self-crosslinking polyacrylate latex (PAL) as a binder for Li-S battery sulfur cathodes.
• To improve the cycling stability and rate performance of Li-S batteries by addressing cathode structural degradation.

Main Methods:

• Synthesis of nano-sized self-crosslinking polyacrylate latex (PAL) with a low glass transition temperature.
• Incorporation of PAL as a binder in sulfur cathodes for Li-S battery fabrication.
• Electrochemical testing to assess cycling stability and C-rate performance.

Main Results:

• The synthesized PAL binder demonstrated nano-sized particles and a low glass transition temperature, ensuring uniform dispersion and good adhesion.
• The crosslinking structure of PAL provided elasticity, effectively accommodating the 80% volumetric change of sulfur during discharge.
• Li-S batteries utilizing the PAL binder exhibited enhanced cycling stability and superior C-rate performance due to a stable cathode structure and reduced polarization.

Conclusions:

• Self-crosslinking polyacrylate latex is an effective binder for stabilizing sulfur cathodes in Li-S batteries.
• The elastic properties of PAL mitigate performance degradation caused by sulfur volume expansion.
• This binder technology contributes to the advancement of high-performance Li-S batteries for next-generation energy storage.