Destroying the Chemical Potential of Spent Lithium-Ion Batteries in Green Soaking Media

Abstract

The recovery of spent lithium-ion batteries is a key link of sustainability. The destruction of the chemical potential of batteries is an important prerequisite for a safe dissociation process and high-value recovery products. NaCl aqueous solution soaking is commonly employed for destroying chemical potential, and the release of pollutants is generally ignored. In this study, NaCl and Na2SO4 aqueous solutions are employed as media for the process of destroying the chemical potential, and the released pollutants are investigated. The galvanic and redox reaction paths are clarified according to the detection of the Cl2 emission, the pH value in the medium, and the phase composition of sediments. For destroying the chemical potential of 1 t of spent LIBs, about 0.52 kg of organic electrolyte solvent is leaked out to the medium; about 4.76 kg of lepodocrocite and magnetite sediment is generated in the Na2SO4 aqueous solution; and 5.49 kg of Al(OH)3 and Fe+3O(OH)-goethite sediment accompanied by 24 L of hazardous Cl2 is generated in the NaCl aqueous solution, causing an about 1 km2 zone seriously polluted by Cl2. A semiquantitative method is used to evaluate the comprehensive effect of commonly used media, and Na2SO4 and FeSO4 are found to be green media. This study aims to provide the pollution information and green suggestions about destroying the chemical potential of spent lithium-ion batteries during their recovery.