CO2-mediated carbothermal reduction coupled with CO2-saturated leaching for selective lithium recovery from spent lithium-ion batteries

Recovering Li from spent battery cathodes is crucial for mitigating scarcity and promoting sustainability. Conventional pyro-hydrometallurgical methods face challenges in Li selectivity due to volatilization losses and inadequate phase control. This study proposes a green approach for sustainable battery recycling. It combines CO 2 -mediated carbothermal reduction with CO 2 -saturated leaching to selectively recover Li from spent lithium-ion batteries. By utilizing graphite-mediated carbothermal reduction under precisely controlled CO 2 atmospheres at 800 °C, Li 2 O are converted into stable Li 2 CO 3 , effectively suppressing Li volatilization. Coupled with CO 2 -saturated leaching at 30 °C, the process achieves 99.8 % Li recovery and 99.9 % Li 2 CO 3 purity. A CO 2 -controlled “Li 2 O-Li 2 CO 3 ″ dual-phase dynamic equilibrium model was established, effectively restricting the migration path of Li. This study enhances understanding of gas–solid equilibrium in carbothermal processes and advances sustainable, efficient battery recycling.