Delamination of lithium iron phosphate from aluminum foil using electrical pulsed discharge without heat, water, or chemicals

Heat-, water-, and chemical-free delamination of lithium iron phosphate (LFP) cathodes from Al foil was achieved using electrical pulsed discharge. Three feedstocks were tested: production scrap lacking electrolytes, freshness-equivalent spent cells (SOH100), and degraded cells (SOH83). Energy inputs of 0.56–0.59 J mg–1 were supplied. Scrap without LiPF₆ required 0.59 J mg–1 to exceed 98% delamination, indicating that interfacial failure depended on Joule heating and thermal stress. Residual LiPF₆ generated HF in situ, weakening the PVDF bond and delivering ≥ 97% delamination across the energy window in SOH100. The spot-like interfacial degradation in SOH83 disrupted current pathways, requiring higher energy and reducing delamination ratio. Thermal modelling showed concentrating current within Al foil raised the interface to 536–554 K, sufficient to melt PVDF and induce through-thickness stress while avoiding bulk heating. The recovered powders from all runs were free of Al-foil contamination (< 0.1 wt.%). X-ray diffraction before and after discharge showed identical LFP peak positions and intensities, confirming no chemical conversion or crystallinity loss occurred, enabling direct recycling. A new electrode with 10 wt.% recovered LFP delivered 148 mAh g–1 at 0.1 C without increased impedance. Pulsed discharge provides high-yield, contamination-free pretreatment for phosphate-cathode direct recycling.