Rapid reductive separation and simultaneous regeneration for direct recycling of spent lithium-ion batteries

The accelerating global adoption of lithium-ion batteries (LIBs) has intensified the need for sustainable and economically attractive recycling technologies that can directly restore the structure and electrochemical performance of degraded cathode materials. A key barrier to practical direct regeneration is achieving clean detachment of active materials from aluminum current collectors while avoiding structural damage or lithium loss, which makes existing mechanical, chemical, and thermal separation methods unsuitable for scalable applications. Here, we report a microwave-assisted reductive separation-regeneration strategy that enables complete polymeric binder decomposition and clean liberation of active materials within 10 min, while simultaneously restoring the cathode structure through lattice-level lithium reintegration via the addition of a small amount of lithium precursor. Under microwave activation, naturally derived tea polyphenols generate reductive radicals that rapidly decompose polyvinylidene difluoride (PVDF) polymeric binders and create a favorable chemical environment for lithium reincorporation into the LiFePO 4 cathode active material lattice. As a result, the regenerated LiFePO 4 cathodes deliver a recovered capacity of 161.6 mAh g −1 at 0.1 C and exhibit excellent long-term cycling stability, retaining 90.8% of the initial capacity (141.6 mAh g −1 ) after 500 cycles at 1 C. This rapid, low-temperature, and energy-efficient microwave-assisted reductive separation-regeneration process is also applicable to spent LiNi x Co y Mn 1-x-y O 2 cathode materials, highlighting its strong potential for scalable and environmentally sustainable battery-recycling applications.