Multifunctional Spinel Structure for Efficient Direct Recycling of Spent Layered Cathodes into Fast-Charging...

Direct recycling is increasingly recognized as a promising solution to alleviate the burgeoning contradiction between the growing demand for lithium-ion batteries (LIBs) and amidst resource shortages. A critical challenge in this process is achieving efficient lithium compensation, which is vital for replenishing lost elements and promoting the reconstruction of degraded structures. Herein, inspired by the concept of "recycle waste with waste," a channel-assisted regeneration strategy is proposed that utilizes waste spinel materials to reconstruct the surface of the spent layered cathode, clearing blocked channels and transforming them into a 3D structure that facilitates rapid lithium-ion transmission. This approach enhances the efficient replenishment of exogenous lithium salts into the particle lattice and prevents intrinsic thermal decomposition during heat treatment due to element deficiencies. The presence of the 3D ion channels can also improve the fast-charging performance of the regenerated cathode material, achieving a capacity retention rate of 87.9% after 500 cycles at 10 C. Additionally, its overall electrochemical performance significantly outperforms that of commercial materials. This work addresses critical challenges in the direct solid-phase regeneration of cathode materials and offers valuable insights for optimizing next-generation LIB recycling technologies.