Recycling of graphite from end-of-life lithium-ion batteries as efficient sulfur host for lithium-sulfur batteries

The recycling of spent graphite from lithium-ion batteries (LIBs) is gaining significant importance, emphasizing the urgent need for effective treatment and recycling methods. This work focuses on the recovery of graphite from waste lithium-ion batteries and the exploitation of feasibility of utilizing the upgraded graphite as the sulfur (S) hosts in lithium-sulfur batteries (LSBs). The recovered graphite (RG) from end-of-life LIBs is etched with potassium hydroxide (KOH) to obtain layered graphite (LG). The results show that the successful implementation of this etching process leads to the formation of LG with enlarged layer spacing. Then, the LG/S cathode material is obtained by melting and diffusing sulfur. Thanks to the synergistic effect between micropores and mesopores, as well as the increased degree of graphitization in LG, the LG/S cathode with up to 74 % sulfur has an initial discharge specific capacity of 1312 mA h g(-1) at a current density of 0.1C. Its reversible capacity stabilizes at 700 mA h g(-1) after 500 cycles, with a low-capacity decay rate of 0.093 % for each cycle. This study presents a novel approach to design cost-effective sulfur-carbon composite cathodes for LSBs by utilizing spent graphite from endof-life LIBs.