Amorphous Lithium Iron Phosphate Glass-Driven Regeneration of Spent LiCoO₂ Cathodes: Synergistic Structural Effects...

Amidst global sustainability imperatives, this study pioneers a solid-state regeneration strategy that transforms spent LiCoO₂ (LCO) cathodes into high-performance materials via amorphous lithium iron phosphate glass (LFPg)-driven structural reconfiguration. Unlike conventional recycling that decomposes cathodes, our approach leverages LFPg's defect-rich framework, high ionic conductivity, and dynamic interfacial activity to directly reconstruct degraded LCO crystals. The LFPg acts as a multifunctional repair agent: creating Li⁺ diffusion channels through disorder engineering, eliminating oxygen vacancies via atomic oxygen transfer, scavenging impurities (e.g., F-, C-F), and homogenizing Co³⁺/Co²⁺ redox states. Regenerated cathodes (LCO:LFPg = 8:2) achieve a record 214.6 mAh/g at 0.5C─surpassing commercial LCO─and retain 86.1% capacity after 100 cycles (163.9 mAh/g) with near-100% Coulombic efficiency, while charge-transfer resistance plummets 78.2%. This energy-efficient, atom-economic process establishes a paradigm for battery circularity, positioning amorphous-phase engineering as the key to sustainable high-value resource recovery.