High Performance Cathode Recovery from Different Electric Vehicle Recycling Streams

Abstract

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, LiNi1/3Mn1/3Co1/3O2 (NMC111). Ni1/3Mn1/3CO1/3(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.

Progress and Status of Hydrometallurgical and Direct Recycling of Li-Ion Batteries and Beyond

“…In the process patented by Rockwood Lithium, Li is recovered from the mother liquor via electrodialysis or membrane separation [125]. Starting from sulfuric acid leaching liquor obtained similar to Zou et al [43], Gratz et al [85] and Zheng et al [126] applied purification process and element doping to obtain enhanced performance NMC (111). Zheng et al's process flowchart is shown in Figure 10.…”

“…After adjusting the Co:Ni:Mn molar ratio to be 1:1:1, Ni 1/3 Mn 1/3 Co 1/3 (OH) 2 was co-precipitated using NaOH and NH 4 OH as alkaline/complexing agent for 48 h at pH 11 and a controlled temperature of 60 • C. Zheng et al reported the results of four 7-day campaigns, where four 30 kg samples of blended spent LIBs with different proportions of LIBs types (LCO, NMC, LMO, LCO, LFP) were processed in a pilot-scale laboratory set-up [126]. The resulted solid Ni 1/3 Mn 1/3 Co 1/3 (OH) 2 products served as precursor for resynthesizing NMC after mixing with 5% excess Li 2 CO 3 and sintering at 450 • C and 900 • C. The obtained active material presented a d 50 from 10 to 14 µm and an electrochemical capacity ranging from slightly over 140 mAh/g to 152 mAh/g at C/5 [126]. These publications are part of process development and commercialization of a LIB recycling pilot plant for Battery Resourcers Inc (Worcester, MA, USA).…”

Challenges in Ecofriendly Battery Recycling and Closed Material Cycles: A Perspective on Future Lithium Battery Generations

“…Hydrometallurgical process steps are capable of producing high product purities. However, plants for counter-flow are larger than those used in pyrometallurgy and require a larger financial investment volume for their construction [21,48,49]. In general, important challenges are to achieve the demanded high recovery rates and, at the same time, high material purities.…”

“…Among other things, a process was developed in which, depending on the active material, 85 to potentially over 95% of the lithium can be recovered by mechanical (includes drying step) and hydrometallurgical means (leaching and subsequent precipitation of the lithium). pyrometallurgy and require a larger financial investment volume for their construction [21,48,49]. In general, important challenges are to achieve the demanded high recovery rates and, at the same time, high material purities.…”

Automated mineralogy as a novel approach for the compositional and textural characterization of spent lithium-ion batteries

“…Accordingly, the anode chemistry in this black mass contains 66.4% LCO and 33.6% NMC. Most of the current recycling processes are selective for one battery chemistry type, however a significant number of processes under development aim to handle cathode chemistry mixtures (Barik et al, 2017;Li et al, 2018;Zheng et al, 2018;Zou et al, 2013). This characterization technique successfully identified the NMC and LCO battery chemistries, and would also be able to detect NCA, LMO and LFP chemistries.…”