Orientation Site-Induced Antiferromagnetic Coupling Stabilizes Reconstructed Cathode From Spent Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Manufacturing

Background:

• Direct regeneration of spent layered ternary oxide cathodes is crucial for resource recovery and circular battery production.
• Long-term stability of these cathodes is limited by intrinsic electronic interactions, particularly Ni migration and rock-salt phase formation, leading to capacity degradation.

Purpose of the Study:

• To stabilize regenerated LiNi0.5Co0.2Mn0.3O2 (NCM) cathodes by controlling Ni-O orbital hybridization.
• To investigate the role of Li vacancies in inducing lattice stress and modulating electronic interactions during regeneration.
• To enhance the cycling durability of regenerated NCM cathode materials.

Main Methods:

• Leveraging pre-existing Li vacancies in spent NCM to create localized lattice stress fields during regeneration.
• Modulating the spin configuration of bridging O anions to induce antiferromagnetic coupling between Ni cations and O anions.
• Analyzing the transition of Ni-O orbital hybridization from π-dominated to σ-dominated interactions.

Main Results:

• Regenerated NCM cathodes exhibited a transition to robust σ-dominated Ni-O orbital hybridization with enhanced covalent character.
• The reinforced bonding framework effectively suppressed Ni migration and defect propagation during cycling.
• The regenerated NCM cathode retained approximately 60% of its initial capacity after 750 cycles.

Conclusions:

• Direct regeneration of spent NCM cathodes can be stabilized by controlling local valence bond evolution.
• The findings offer new design principles for stabilizing regenerated cathode materials and improving cycling reversibility.
• This approach contributes to sustainable resource recovery and circular battery manufacturing.