High performance Li-S batteries using cathodes produced with carbons derived from physically activated recycled surgical masks

Activated carbon derived from recycled, discarded surgical masks has been used as a sulfur host for lithium-sulfur (Li-S) batteries. The activation process was carried out using physical methods, which are simpler and cleaner than chemical approaches. Two activating agents, CO 2 and steam, were employed, with steam resulting in somewhat higher BET surface and pore volume, as well as better electrochemical performance, leading to a greater number of tests being carried out on this material. When mixed with sulfur (∼70%), the steam-activated carbon demonstrated outstanding electrochemical properties, including good rate capability (an average capacity ranging from 970 mAh g − 1 at 0.1C to 360 mAh g − 1 at 2C), high reversible capacity and impressive cycling stability (average capacity ∼850 mAh g − 1 at 0.3C after 400 cycles). It also showed good areal capacity values and high lithium-ion diffusion coefficients ( D Li + ). This study underscores the use of physical activation as a simple, clean, easy, and efficient alternative to improve the performance of carbons in high performance Li-S batteries.