High Performance Cathode Recovery from Different Electric Vehicle Recycling Streams

For environmental and sustainability reasons, spent Li-ion batteries must be recovered and recycled so that the full promise of an electrified future is realized. Li-ion battery recycling streams pose a serious challenge to all existing recycling technologies because of their unknown and diverse chemistry. In the work described in this paper, four representative recycling streams were used to demonstrate the flexibility of the recycling process developed at Worcester Polytechnic Institute (WPI) to accommodate a variable feed and to generate consistent quality cathode material, LiNi_1/3Mn_1/3Co_1/3O₂ (NMC111). Ni_1/3Mn_1/3CO_1/3(OH)₂ precursors derived from four recycling streams were produced by a hydroxide coprecipitation method in a continuous stirred tank reactor. It took 2 days for the coprecipitation reaction to reach steady state. A possible evolution of the precursor particles up to the steady state was proposed. Both the precursors and the cathodes from these four different recycling streams exhibit similar morphology, particle size distribution, and tap density. Moreover, these recovered cathode materials display similar electrochemical properties. Surprisingly, these recovered NMC111s have better rate capability than a commercial NMC111 prepared from virgin materials. The different chemical compositions of the incoming recycling streams were shown to have little observed effect on the recovered precursor and resultant cathode material generated by the WPI-developed recycling process with advantages including no sorting, low temperature, and high quality recovered battery materials. Therefore, the WPI-developed process applies to different spent Li-ion battery waste streams and is, therefore, general.