Copper Impurity Effects on LiNi(1/3)Mn(1/3)Co(1/3)O2 Cathode Material

Area of Science:

• Materials Science
• Electrochemistry
• Recycling and Sustainability

Background:

• Lithium nickel manganese cobalt oxide (NMC) is a key cathode material for lithium ion batteries.
• Recycling NMC from spent batteries is crucial for sustainability.
• Understanding impurity effects is vital for optimizing recovered materials.

Purpose of the Study:

• To investigate the detailed effects of copper (Cu) impurity on the crystal structure and electrochemical properties of NMC.
• To compare the performance of pure NMC with NMC containing Cu impurities synthesized from a battery recovery stream.

Main Methods:

• Synthesis of pure NMC and Cu-impurity-containing NMC from a lithium ion battery recovery stream.
• Characterization using Scanning Electron Microscopy (SEM) to observe particle morphology.
• Analysis of crystal structure and lattice parameters using X-ray Diffraction (XRD) refinements.
• Electrochemical testing, including 150 cycles at 2C rate, to evaluate capacity retention.

Main Results:

• SEM revealed slightly larger precursor particles for pure NMC compared to Cu-impurity-containing NMC.
• XRD refinements indicated different extents of lattice parameter changes after cycling for pure and Cu-containing NMC.
• Copper-containing NMC demonstrated more stable capacity retention than pure NMC after 150 cycles.

Conclusions:

• Copper impurities, even minor ones, can significantly influence the structural stability of NMC cathode materials.
• The presence of Cu impurity leads to a more stable capacity retention in recycled NMC, likely due to minor changes in lattice parameters.
• This finding has implications for improving the quality and performance of recycled cathode materials.