Recycling of End‐of‐Life Lithium–Sulfur Battery Cathodes for CO2 Capture

Polysulfides promoted the exfoliation of carbon nanotube (CNT) walls and increased the surface area of recycled cathode powder, thereby enhancing CO₂ capture. Concentrated acid treatment in recycling further improved the CO₂ uptake by reducing sulfur content and introducing oxygen-containing functional groups. This work demonstrates that sulfur-carbon composites recycled from end-of-life Li–S batteries can be reused to capture CO₂.

Abstract

Landfilling of end-of-life lithium–sulfur (Li–S) batteries results in the loss of valuable materials, soil contamination from hazardous electrolytes, and risks of explosions caused by reactive lithium metals. Recycling Li–S batteries is crucial for battery sustainability and circularity. However, recycling of Li–S battery cathodes imposes a challenge because sulfur removal is cumbersome and costly. This study demonstrates that sulfur-carbon composites recycled from end-of-life Li–S batteries can be reused to capture CO₂. Specifically, battery charge/discharge cycling expands the lattices of carbons, causing exfoliation to enlarge the surface areas that enhance CO₂ adsorption. The acid treatment inserts oxygen-functional groups into the sulfur-carbon composite, further promoting CO₂ capture. The findings unveil that battery charge/discharge cycling increases the CO₂ uptake efficiency of recycled sulfur-carbon composite, highlighting a cost-effective recycling strategy and a promising reuse pathway for end-of-life sulfur-based batteries to achieve deeper decarbonization.