Ti2SnC MAX phase with in-situ generated Sn nanoparticles for lithium-ion storage

Tin-based anode materials, while notable for their high volumetric capacity, often experience rapid capacity decay during cycling due to volume expansion, pulverization, and agglomeration. Herein, we synthesized a nanoscale composite through a thermo-mechanochemical process utilizing the mechanical anisotropy of Ti 2 SnC MAX phase. This composite incorporates in-situ generated nano-Sn particles within a Ti 2 SnC matrix characterized by Sn vacancies. The strategic integration of uniformly nano-Sn particles and the refined granularity of the Ti 2 SnC matrix markedly enhance the electrochemical properties of the anode. Impressively, it maintains a volumetric capacity of 1430 mAh cm −3 after 400 cycles, equivalent to approximately 3370 h, at a current density of 0.1 A g −1 . Post-cycling analysis reveals the transformation of Sn into a nanocrystalline state and the gradual exposure of more Sn active sites within the Ti 2 SnC matrix, significantly enhancing lithium-ion storage performance. This study highlights the crucial role of the A-site atomic layer in MAX phases and, considering the compositional diversity of MAX phases, offers new insights and broad applicability in lithium-ion battery technologies.