CO2 capture utilizing Li4SiO4 from spent lithium-ion batteries and iron tailings offers eco-friendly benefits

Carbon capture and storage stand as a pivotal technology in the battle against global climate change. The development of economically viable CO2 capture materials, coupled with the recycling of solid wastes, poses a significant challenge in the pursuit of carbon neutrality. Herein, we propose a process to synthesize a promising high-temperature sorbent, Li4SiO4, using spent lithium-ion batteries and iron tailings. Li4SiO4 synthesized under optimal process conditions demonstrates exceptional CO2 capacity and cycle stability (0.25 g/g, 100 cycles), with a preparation cost merely amounting to 1/7 of traditional methods, rendering it industrially feasible. Moreover, elucidating the intricate relationship between impurity elements in the feedstock and the CO2 capture capacity of the adsorbent holds considerable significance in guiding material synthesis strategies. A systematic evaluation of solid waste purity and impurity elements on CO2 capture capacity, through a combination of experiments and theoretical calculations, reveals that lower purity solid waste containing favorable impurities (96.78 % Li2CO3 and 90.35 % SiO2) enhances the CO2 capture efficiency of the synthesized Li4SiO4. This innovative work establishes a direct link between trace impurities and macroscopic properties, providing a viable decarbonization pathway and fostering high-value secondary utilization of solid waste under short and economical processes.