Integrating High-Efficient Delamination and Structural Reconstruction Boosting Direct Regeneration of Spent Cathode Materials.

Abstract

Direct regeneration presents a promising solution for tackling spent lithium-ion batteries due to its environmental and economic advantages. Nonetheless, the effectiveness of direct regeneration hinges on the efficient and precise separation of cathode materials from current collectors. Current separation methods not only suffer from incomplete separation and low delamination efficiency but also risk inflicting damage to the already degraded surface structure of cathode materials, which further renders the direct regeneration less effective. Herein, an approach is introduced that synergistically achieves high-efficient delamination and surface reconstruction of spent LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) by catalytically activating potassium peroxymonosulfate. This approach achieves delamination of cathode materials from current collectors with a separation efficiency over 99% within only 2 min. Moreover, the surface reconstruction is simultaneously accomplished during the delamination process, building fast lithium-ion diffusion pathway, greatly reducing the lithium-ion migration barrier. Consequently, the NCM523 regenerated through this method successfully restores its capacity to commercial level at 152 mAh·g^-1 and maintains outstanding cycling stability, retaining 75% of its capacity after 1000 cycles. The findings underscore the necessity of complete separation of cathode materials from current collectors and surface structural reconstruction in direct regeneration and offer critical insights into optimizing sustainable recycling processes for spent lithium-ion batteries.