Here, we investigate the recovery and reuse of polyvinylidene fluoride (PVDF) binders from both homemade and commercial cathode films in Li ion batteries. We find that PVDF solubility depends on whether the polymer is an isolated powder or cast into a composite film. A mixture of tetrahydrofuran:N‐methyl‐2‐pyrrolidone (THF : NMP, 50 : 50 v/v) at 90 °C delaminates composite cathodes from Al current collectors and yields pure PVDF as characterized by ¹H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), wide‐angle X‐ray scattering (WAXS), and scanning electron microscopy (SEM). PVDF recovered from Li ion cells post‐cycling exhibits similar performance to pristine PVDF. These data suggest that PVDF can be extracted and reused during Li ion battery recycling while simultaneously eliminating the formation of HF etchants, providing an incentive for use in direct cathode recycling.

中文翻译：

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锂离子电池复合正极粘合剂的回收与再利用

在这里，我们研究了从锂离子电池中的自制和商用正极膜中回收和再利用聚偏二氟乙烯 (PVDF) 粘合剂。我们发现 PVDF 溶解度取决于聚合物是孤立的粉末还是浇铸成复合薄膜。四氢呋喃：N-甲基-2-吡咯烷酮（THF：NMP，50：50 v/v）的混合物在 90 °C 下将复合正极与 Al 集流体分层，并产生纯 PVDF，其特征为¹H核磁共振（NMR）、凝胶渗透色谱（GPC）、广角X射线散射（WAXS）和扫描电子显微镜（SEM）。从锂离子电池循环后回收的 PVDF 表现出与原始 PVDF 相似的性能。这些数据表明，PVDF 可以在锂离子电池回收过程中被提取和重复使用，同时消除 HF 蚀刻剂的形成，从而为直接阴极回收的使用提供了动力。