Using strategies employed in synthetic chemistry, we investigated the chemicals found in lithium iron phosphate (LFP) spent battery via an initial dichloromethane (DCM) extraction of the individual cathode and anode. The pre- and post-treated electrodes and DCM extracts were examined using a range of analytical techniques. A total of 26 compounds were identified, which included the following: (1) some of the benchmark materials, LFP, lithium hexafluorophosphate (LIPF6), polyvinylidene fluoride (PVDF), graphite and carbon black; (2) NMR spectroscopy of DCM extract revealed five main chemicals, which were ethylene and propylene carbonate solvents, LiPF6, lithium tetrafluoroborate (LiBF4), and an unknown fluorochemical; (3) analysis of the water-treated DCM extract revealed 21 chemicals by GCMS, several fluorochemicals; (4) 12 chemicals were found in both cathode and anode and three only in the anode; (5) only 13 of the 21 chemicals could be properly named, whilst four had some notable functionality and three could not be identified; and (6) ICP analysis revealed high levels of Al, Cu, Fe, V, and Zn in both electrodes and spent electrolyte. The high number of chemicals present in the spent electrolyte and electrodes suggest battery manufacturers use many proprietary chemicals to enhance battery properties. This procedure allows insight and identification of chemicals present in waste LIBs which will require advanced chemical techniques to recover high yields and purity of recycled materials and the need to dispose of hazardous waste.
Collis et al. (Wed,) studied this question.