Enhancement in exfoliation and recycling of lithium-ion batteries materials based on supercritical CO2 system
The supercritical(SC) CO2 was innovatively adapted to achieve efficient multi-component exfoliation and valuable component resource recovery from spent LIBs,based on improving the flow characteristics of high-viscosity solvent fluids through the use of the preferable dissolution and permeability properties of SC fluids.Based on surface group properties,particle aggregation morphology,and particle size distribution characteristics,the mechanism of electrode material detachment and organic binder transport was studied. The results indicate that the optimum experimental conditions for SC CO2 are a temperature of 70 ℃,a pressure of 8 MPa,and a duration of 20 min,with dimethyl sulfoxide(DMSO) as a cosolvent. Consequently,the liberation efficiency of the cathode increased to 96.7％. It is concluded that the binder is dissolved and removed from the surface of the electrode material,and is separated from the electrode material under the synergistic transport of CO2 fluid. Thus,after removing the organic binder,the agglomeration of the cathode decreased,and the cathode particles were dispersed into smaller fragments. The waste electrode materials recycling process in this article has the characteristics of high efficiency and environmental protection,which meets the requirements of green and sustainable development in the field of electronic waste recycling.
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