Separation of Lithium-Ion Battery Cathode Active Materials by Vaporizing the Current Collector With Pulsed Current

The cathode active materials in lithium-ion batteries (LIBs) possess significant recycling value. However, separating these materials from the binder and the cathode current collector (Al foil) is challenging. This study proposes a method for separating cathode active materials by vaporizing the current collector by underwater pulsed discharge. Discharge experiments were conducted with voltages spanning from 3 to 6 kV and using the cathode sheet as the load. The simulation indicated that the temperatures of the current collector and the binder surpassed their vaporization and pyrolysis temperatures respectively. The separate effects of the experimental products are as follows: the current collector was almost completely removed in big-particle products (particle size $>$ 74 $\mu$ m), and partially separated in medium-particle products (25 $\mu$ m $<$ particle size $<$ 74 $\mu$ m). The binder was entirely removed in small-particle products (particle size $<$ 25 $\mu$ m). With the addition of alkali liquor, the concentration of the aluminum in the small-particle products could be further diminished, thus cathode active materials separated from both the binder and the current collector simultaneously. Furthermore, the results of phase detection indicated that there was essentially no alteration in the cathode active materials before and after discharge, and therefore, could potentially be directly reused in LIBs. Thus, this new method enables fast and eco-friendly separation of cathode active materials from both current collectors and binders in LIBs.