With the wide application of ternary lithium-ion batteries, the increased usage of batteries has resulted in a corresponding rise in the amount of discarded batteries. Here, we propose an efficient and prioritized lithium extraction process with a low environmental impact for the recovery of valuable metal components from spent LiNi0.5Co0.2Mn0.3O2 cathode materials. SO2 calcination–water leaching was used to recover Li, while H2SO4 acid leaching facilitated the recovery of Ni, Co, and Mn, yielding a precursor solution for the treatment of discarded NCM batteries. The effects of calcination temperature, calcination time, water leaching time, water leaching liquid–solid ratio, different battery ratios, acid leaching time, acid leaching liquid–solid ratio, and acid leaching temperature were optimized. The acid leaching process was controlled by surface chemical reactions through kinetic analysis. Under optimal conditions, Li was converted to soluble Li2SO4, achieving an impressive leaching rate of 99.7%. Ni, CO, and Mn were converted to their respective oxides. Furthermore, it was demonstrated that the formation of Li2Mn(SO4)2 from Mn with Li during calcination enhances the leaching efficiency across different battery composition ratios. The activation energies of Ni, Co, and Mn during the acid leaching process were determined by kinetic calculations, yielding values of 130.19, 133.05, and 134.09 kJ mol–1, respectively. This study provides a novel method for recycling spent NCM cathode materials.
Polyacrylate polymer is a promising polymer matrix for gel polymer electrolyte (GPE) in lithium-ion batteries . Herein, in-situ polymerized poly(ethylene glycol phenyl etheracrylate) (PEGPEA) based GPE combined with 1 M LiPF6 in ethylene carbonate/dimethyl carbonate/ethyl methyl carbonate (EC/DMC/EMC, 1:1:1 in volume) solvents was introduced. The maximum recoverable strain of the in-situ polymerized PEGPEA-GPE was up to 99%. The outstanding interfacial compatibility between PEGPEA-GPE and the lithium electrode was also obtained. Surprisingly, lithium dendrite was effectively suppressed in charge-discharge cycling because of polymer-enhanced solid electrolyte interphase (SEI) and excellent contact interface. Furthermore, the PEGPEA-GPE exhibited wide electrochemical stability window up to 4.9 V versus Li + /Li, and achieved an ionic conductivity of 3.35 × 10 −3 S cm −1 at 25 °C. When used as electrolyte, the Li[Ni 0.5 Co 0.2 Mn 0.3 ]O 2 /PEGPEA-GPE/Li batteries showed high discharge capacity retention rate of 97.5% after 70 charge-discharge cycles and considerable discharge rate capability, i.e., 155 mAh g −1 0.2C, 142 mAh g −1 0.5C, 120 mAh g −1 1C, 60 mAh g −1 2C. These results demonstrate that this highly elastic in-situ polymerized PEGPEA-GPE is a potential electrolyte system for high-performance polymer electrolyte lithium-ion batteries and has excellent application prospects in wearable and flexible batteries.