A novel water-soluble recyclable binder for green regeneration of active materials in lithium-ion batteries

The binder plays a crucial role in the mechanical stability, ionic conductivity, and cycle life of the electrode. Herein, a novel water-soluble green binder LALi is prepared through a simple heating process to copolymerize deprotonated α-lipoic acid with acrylamide. Compared with conventional PVDF binders, lithium iron phosphate batteries assembled based on LALi exhibit excellent long-term cycling stability and higher apparent Li + diffusion coefficients D Li + A = 5.93 × 10 − 8 . At a 2.0C rate, LALi displays an initial discharge capacity of 122.4 mAh g −1 and achieves a high coulombic efficiency of 99.9%. After 2100 cycles, the capacity steadily decays to 57.6 mAh g −1 , which is significantly higher than that of batteries assembled with conventional PVDF binders (45.4 mAh g −1 ). Most importantly, the green, low-cost, and highly efficient regeneration and recycling of active materials and binders can be achieved through a simple water-soluble method. This strategy offers a new pathway for the large-scale green direct regeneration of lithium-ion battery active materials in the future.