Synthesis of sandwich-like structured Sn/SnOx@MXene composite through in-situ growth for highly reversible lithium storage

This study presents a nanostructured Sn/SnOx@Ti3C2 composite by in-situ growth of Sn/SnOx nanoparticles on the interlayer of 2D MXene (Ti3C2Tx) nanosheets through facile electrostatic attraction and liquid phase reduction. X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy results illustrate that Sn/SnOx nanoparticles are uniformly distributed into the MXene (Ti3C2Tx) interlayer, forming a sandwich-like nanostructured composite. MXene (Ti3C2Tx) nanosheets suppress Sn/SnOx nanoparticles’ volume expansion and agglomeration and accelerate the Li-ion and electron transition due to the distinguished confinement effect and excellent graphite-like layered structure. Furthermore, Sn/SnOx nanoparticles are embedded as pillars to enhance the longitudinal structural stability of MXene matrix by preventing the re-stacking of nanosheets during lithium insertion/extraction. The nanosized particles still reduce lithium migration path and increase active areas. Therefore, the Sn/SnOx@Ti3C2 composite maintains 594.2 mAh g−1 after 200 cycles with a capacity recovery after 100 cycles. The synergistic effect of Sn/SnOx on MXene facilitates Sn/SnOx@Ti3C2 nanostructures, thereby exhibiting excellent electrochemical properties for lithium-ion batteries.