Researchers uncover atomic flaw blocking lithium battery recycling

Researchers at the Hong Kong University of Science and Technology (HKUST) have identified a critical atomic-level flaw that hinders lithium battery recycling: trace amounts of aluminum contamination within cathode materials. Their study reveals that aluminum atoms infiltrate nickel–cobalt–manganese (NCM) cathodes by substituting cobalt atoms, forming ultra-stable aluminum–oxygen bonds. This atomic substitution effectively locks key metals like nickel, cobalt, and manganese in place, making them significantly harder to extract using the acidic solvents commonly employed in recycling processes. Advanced imaging techniques and quantum modeling confirmed that even minimal aluminum presence fundamentally alters the chemical behavior of cathode materials, posing a substantial obstacle to efficient metal recovery. The research also highlights that aluminum’s impact varies with different solvents—slowing metal release in formic acid, accelerating it in ammonia, and producing unpredictable results in deep eutectic solvents—underscoring the complexity of recycling chemistry. Moreover, common mechanical shredding methods may exacerbate aluminum contamination through friction