Integrated process of CO2 sequestration and recycling spent LiFePO4 batteries

Abstract

Sequestration of CO2 and recycling spent Li-ion batteries (LIBs) are essential for our society owing to the increased demands for decarbonization and energy/resources conservation. However, conventional CO2 fixation and LIBs recovery strategy are always accompanied with harsh reaction conditions or complex process. Herein, as an integrated process, CO2 was designed as a leaching agent to recycle the spent LiFePO4 at the mild room temperature. Thanks to the weak acidity of H2CO3, low leaching of Fe and P elements can guarantee the high extraction selectivity of lithium. Besides as the leaching agent, CO2 also chemically precipitates the leached Li+to produce the value-added Li2CO3 product. Further utilizing FePO4 residue as precursor to synthesize Na4Fe3(PO4)2P2O7 cathodes for Na-ion batteries could achieve a decent electrochemical performance. Life-cycle analysis reveals the currently developed CO2-leatching strategy enables low energy consumption, reduced greenhouse gas emission and considerable economic profit, showing great application potential.