Enhancement in liberation of electrode materials derived from spent lithium-ion battery by pyrolysis

In this study, pyrolysis was utilized to enhance the liberation of electrode particles in the recycling process of spent lithium-ion batteries. Pyrolysis characteristics of cathode and anode materials and the effects of pyrolysis on the liberation of electrode materials were fully investigated. Afterwards, scanning electron microscope coupled with an energy dispersive spectrometer and X-ray photoelectron spectroscopy were used to reveal the changes of mineralogical characteristics of electrode materials before and after pyrolysis. The results indicate that organic binder wrapped on electrode particles is the main reason that electrode materials are hard to liberate from foils and difficult to liberate each other. The optimum pyrolysis temperature of organic binders in electrode materials is 500 °C and the main pyrolysis products are fluorine-containing benzene and ester electrolyte. The liberation efficiency of cathode increases from 82.88% to 99.78% by pyrolysis, while that of anode increases from 88.08% to 99.60%. Meanwhile, adequate liberation of pyrolytic electrode materials requires a shorter period of time. Electrode materials from pyrolytic electrode are mainly concentrated in −0.045 mm size fraction, and they are up to 82.49% and 78.91% respectively for cathode and anode materials. 5106.