Valorization of hazardous graphite from black mass (NMC 111) of lithium-ion battery recycling via KOH activation for functional carbon design

• Hazardous graphite from spent LiBs was converted into activated carbons. • Optimized conditions yielded ACs with a surface area up to 678 m 2 /g. • XRD confirmed graphitic crystallinity, while Raman showed increased defect density. • XPS revealed enhanced oxygen functionalities, including C–O, C=O, and CO 3 2− groups. • The process supports waste prevention and cleaner production in a circular economy. The rapid adoption of lithium-ion batteries (LiBs) in energy storage has driven research into resource recovery. This study converts hazardous graphite from the black mass (NMC 111) of spent LiBs into functional activated carbons (ACs) via KOH activation. Tailoring the synthesis at 800 °C and a graphite-to-KOH ratio of 1:6 produced AC with a surface area of 678 m 2 /g and a total pore volume of 0.442 cm 3 /g. The material showed a balanced micropore–mesopore structure, with micropores contributing 53 % of the total pore volume. The material showed a balanced micropore–mesopore structure, with micropores contributing 53 % of the total volume. XRD confirmed preserved graphitic crystallinity with a dominant (002) peak at 26.52°. Raman spectroscopy indicated increased defect density (I D /I G = 1.053), facilitating porosity formation. SEM and TEM revealed a transition from smooth graphite layers to a porous, defect-rich structure, with TEM highlighting mesopore-like voids and distorted graphitic domains featuring edge defects. XPS identified surface modifications, including a higher proportion of sp 2 carbon and oxygen-containing groups (C–O, C=O, C-OH, CO 3 2− ). TGA demonstrated stability (∼900 °C) under inert conditions and enhanced reactivity in oxidative environments. This work valorizes LiB-derived graphite waste into ACs, supporting circular economy strategies and demonstrating potential for industrial scalability.