Effect of Residual Trace Amounts of Fe and Al in Li[Ni1/3Mn1/3Co1/3]O2 Cathode Active Material for the Sustainable Recycling of Lithium-Ion Batteries

Abstract

As the explosive growth of the electric vehicle market leads to an increase in spent lithium-ion batteries (LIBs), the disposal of LIBs has also made headlines. In this study, we synthesized the cathode active materials Li[Ni1/3Mn1/3Co1/3]O2 (NMC) and Li[Ni1/3Mn1/3Co1/3Fe0.0005Al0.0005]O2 (NMCFA) via hydroxide co-precipitation and calcination processes, which simulate the resynthesis of NMC in leachate containing trace amounts of iron and aluminum from spent LIBs. The effects of iron and aluminum on the physicochemical and electrochemical properties were investigated and compared with NMC. Trace amounts of iron and aluminum do not affect the morphology, the formation of O3-type layered structures, or the redox peak. On the other hand, the rate capability of NMCFA shows high discharge capacities at 7 C (110 mAh g−1) and 10 C (74 mAh g−1), comparable to the values for NMC at 5 C (111 mAh g−1) and 7 C (79 mAh g−1), respectively, due to the widened interslab thickness of NMCFA which facilitates the movement of lithium ions in a 2D channel. Therefore, iron and aluminum, which are usually considered as impurities in the recycling of LIBs, could be used as doping elements for enhancing the electrochemical performance of resynthesized cathode active materials.

Utilizing the Intrinsic Thermal Instability of Swedenborgite Structured YBaCo4O7+δ as an Opportunity for Material Engineering in Lithium-Ion Batteries by Er and Ga Co-Doping Processes

“…Noticeably, the first semicircles in a high frequency region that are related to the film resistance induced by the formation of solid electrolyte interphase (SEI) between electrodes and electrolytes gradually shrank with an increased cycle number from 10 to 50 in both samples (see the insets in the figures). It is hard to intuitively interpret the abnormal phenomenon about the gradual decrease of film resistance, which is contrary to other relevant research [30,31]. In the meantime, the second semicircles in a low frequency region regarding charge transfer resistance (R ct ) indicated incremental trends in both samples during cycling due to the structural degradation of the cathode active materials.…”

One-pot synthesis of LiAlO2-coated LiNi0.6Mn0.2Co0.2O2 cathode material

“…It is therefore possible that Al 3+ substitutes Ni 3+ and Co 3+ . Also, since the ionic radii of Ni 3+ (0.56 Å), Co 3+ (0.545 Å), and Mn 4+ (0.54 Å) are close to that of Al 3+ (0.53 Å), substitution may occur [36,37]. Due to a large difference in ionic radii between Al 3+ (0.53 Å), Li + (0.76 Å, 3a) and Ni 2+ (0.69 Å), the substitution in these cases cannot occur.…”

“…Also, since the ionic radii of Ni 3+ (0.56 Å), Co 3+ (0.545 Å), and Mn 4+ (0.54 Å) are close to that of Al 3+ (0.53 Å), substitution may occur. 36,37 Due to a large difference in ionic radii between Al 3+ (0.53 Å), Li + (0.76 Å, 3a) and Ni 2+ (0.69 Å), the substitution in these cases cannot occur. Refinement of the occupancy factor also confirms this hypothesis since the occupation of Co, Mn, and Ni is reduced, which means that they have been substituted by another element, in this case Al 3+ .…”

“…It has been reported that an increased T Li could enable Li + intercalation/deintercalation kinetics. 37 This property is obviously beneficial for the electrochemical behaviour observed in NMC-B, leading to expected better performances in NMC-B compared to NMC-A and NMC-P.…”

The enhancement of cyclability of Ni‐rich LiNi 0 . 9 Co 0 . 05−x Mn 0 . 05 Zn x

“…16 In our previous study, it was confirmed that various metal and nonmetal impurities are present in the regenerated cathode active materials after the purification process. 17 In addition, the effects of relatively high concentrations of impurities such as Fe, 18,19 Al 20,21 Cu, 22 and Na 23 on the resynthesized cathode active materials were investigated individually at impurity levels. However, Zn and Ca have been overlooked in related studies on impurity effects because of their negligible concentration.…”