Spent NCM111 Cathode Material as a Catalyst for Oxidative Cleavage of β-O-4 Linkage in Lignin

The recovery and reuse of electrode materials of spent lithium-ion batteries (LIBs) are important for the sustainable development of the LIB industry. Herein, NCM111 (LiNi_0.33Co_0.33Mn_0.33O₂) cathode material from spent LIBs is recovered and its catalytic activity for the oxidative cleavage of β-O-4 linkages in model compounds and organosolv lignin is explored. The spent NCM111 is rich in oxygen vacancies (OVs) accumulated during the long-term charge-discharge cycling. The reactive oxygen species trapping experiments and density functional theroy (DFT) calculation indicate that the abundant OVs can adsorb and activate the oxygen molecules, which afford the NCM111 with the catalytic activity. It is found that besides the catalytic activity in oxidative cleavage of the β-O-4 linkage in lignin model compounds, the spent NCM111 can also catalyze the depolymerization of organosolv lignin, yielding 17.5% aromatics, such as vanillin, benzoic acid, and phthalic acid, indicating the potential economic value of spent NCM materials.