Shearing‐force‐driven delamination of waste residue into oxidatively stable MXene composites for high‐performance Si anode

Abstract The low yield of MXene is normally related to the delaminating step, contributing to the key technical challenges in moving toward industrial applications. Here, a shearing‐force‐driven strategy is proposed for re‐exfoliating waste MXene residue to prepare oxidatively stable MXene composites in a low‐cost manner, where the strong shear stress in the assisted solvent, such as carbon nanotubes (CNTs), chitosan (CS), and polyacrylamide (PAM) aqueous solutions, acts on the surface of MXene (Ti 3 C 2 T x ) through coordination between hydroxyl and Ti atoms, resulting in a rapid and efficient exfoliation of waste Ti 3 C 2 T x residue under stirring. Furthermore, this formed coordinate bond helps to stabilize the low‐valent Ti atoms on the surface of MXene, thereby enhancing the oxidative stability of Ti 3 C 2 T x . Besides, the CNT@MXene composite is selected to construct a free‐standing membrane to encapsulate Si nanoparticles, achieving a high and reversible capacity after 50 cycles. This work supports the concept of valorizing waste and adopts a fluid shear force‐assisted method to re‐exfoliate waste residues, which greatly reduces the cost of processing and improves the chemical stability of MXene. More importantly, this work has uncovered a new direction for the commercialization of MXene composites and has significantly improved the real‐world applications of MXene‐based materials.