Patent ID: 11802244

Abstract:
The gemini surfactant for use in recycling lithium batteries is an anionic surfactant having the generic formula CxH2x+1(CyH2y+1) PO4CzH2zPO4CxH2x+1(CyH2y+1). An example of the surfactant is shown as compound 1 below where (x=5, y=2, z=4). Current solvents used to remove polymer binders include Nmethyl-2-pyrrolidone (NMP), N—N-dimethylformamide (DMF), N—N-dimethylacetamide (DMAC), N—N-dimethylsulfoxide (DMSA), and ethanol. The benchmark solvent often used to dissolve polymer binders is NMP. However, the present surfactants are phosphate-based surfactants and are used with a phosphate-based solvent, namely, triethyl phosphate (TEP), which is cheaper and more environmentally friendly than NMP. However, TEP has weaker binder solubility than NMP. Thus, the present surfactants are used with sonication to remove polymer binders.