From battery waste to catalytic innovation: upcycling spent lithium-ion battery cathodes into La-Ni based perovskites for synergistic CO2 valorization and low-tar biomass gasification

The development of cost-effective and high-performance composite metal catalysts is a crucial strategy for upgrading syngas in CO2 biomass gasification. With the rapid advancements in new energy technologies, spent lithium-ion batteries (LIBs) present great recycling value owing to their high concentrations of valuable Li and transition metals. By utilizing cathode materials enriched from spent LIBs as a sustainable source of Li and Co, we developed a series of modified La-Ni perovskite catalysts. Among them, LNO/2L2C-L exhibited remarkable catalytic activity, achieving a syngas yield 6.05 times higher than that of non-catalytic gasification while realizing nearly 100% carbon conversion and tar reduction rates. Meanwhile, it demonstrated excellent catalytic stability in the cyclic gasification. Based on the characterization and DFT calculation results, the substitution of Li+ and Co3+ from LIBs at perovskite sites generates abundant surface O−/O2− species, which significantly enhances catalytic gasification efficiency of biomass. Simultaneously, the cracking effects exerted by Ni-Co sites on C-C and C-H bonds in aromatic rings and Li+ on O-H bonds significantly facilitate the removal of tar. This work offers a promising strategy for transforming hazardous battery waste into cost-effective catalysts while advancing carbon-negative biomass conversion.