Porous silica-sulfur composite and lithium-sulfur battery containing the same

Polysulfide-inhibiting lithium-sulfur cathode material using sulfur-loaded hexagonal plate-like mesoporous silica

This technology is a cathode material that suppresses sulfur loss and enhances electrochemical reversibility by loading sulfur into the pores of non-conductive mesoporous silica with a hexagonal plate-like structure.

Lithium-sulfur batteries have historically faced issues where lithium polysulfides generated during charge-discharge cycles dissolve into the electrolyte and migrate out of the cathode reaction zone. This leads to capacity degradation and a shortened lifespan.

This technology utilizes hexagonal plate-like mesoporous silica with a thickness of 150–400 nm as a host, employing a two-step melt-diffusion method to fill the pores with a high concentration of sulfur. Despite being non-conductive, the silica's pore structure and surface properties are engineered to strongly trap polysulfides. It can be applied to lightweight batteries for drones and air mobility, high-volumetric-capacity lithium-sulfur cells, and interlayer materials between separators and cathodes, allowing for the use of cost-effective silica to suppress the shuttle effect and increase sulfur utilization.

‍

‍

Key Features:

• Hexagonal plate-like mesoporous silica with a thickness of 150 to 400 nm and a ratio of surface width to thickness of 0.01 to 0.2
• Sulfur loaded within the pores of the non-conductive mesoporous silica at a level of 0.9 to 25 mg/m2
• Cathode composite layer formed by physically mixing a carbon-based conductor, the mesoporous silica-sulfur composite, and a binder
• Interlayer containing the silica-sulfur composite, positioned between the cathode and the separator in the electrolyte region between the cathode and anode

‍