Porous Activated Carbons Derived from Coffee Waste for Use as Functional Separators in Lithium-Sulfur Batteries

A novel approach has been proposed for improving the performance of lithium-sulfur batteries (LSBs) with a carbon-based material as an interlayer between the cathode and separator. With this method, the cross-over of lithium polysulfides (LiPS) to the anode is suppressed, increasing reutilization of the sulfur cathode. In this study, activated carbons (ACs) were prepared using coffee waste as a carbon source and potassium hydroxide (KOH) as an activation agent at various reaction temperatures ranging from 500 to 800 degrees C. With the rise in heating temperature, the specific surface areas, micro-surface areas, and micro-pore volumes of the AC samples gradually increased. In particular, the AC sample prepared at 800 degrees C and used as a functional separator for LSB exhibited improved capacity and cycling performance while suppressing the LiPS shuttle effect.

Automated summary

A novel approach using a carbon-based material as an interlayer in lithium-sulfur batteries (LSBs) has been proposed to enhance their performance. By suppressing the crossover of lithium polysulfides to the anode, the reutilization of the sulfur cathode is increased. Activated carbons (ACs) were prepared using coffee waste and potassium hydroxide as an activation agent at different reaction temperatures, showing improved surface areas and pore volumes. The AC sample prepared at 800 degrees C exhibited enhanced capacity and cycling performance as a functional separator for LSB while suppressing the shuttle effect of lithium polysulfides.