Tin-Based Metal-Organic Framework Derived Sn-SnO2/Sn2O3@C With a Heterogeneous Structure as an Advanced Anode for High-Performance Lithium-Ion Batteries.

Abstract

Tin-based oxides are recognized as promising high-capacity anode materials for lithium-ion batteries owing to their high theoretical specific capacity and favorable operating voltage. Nevertheless, their widespread practical implementation has been hindered by substantial volume fluctuations during lithiation/delithiation processes, as well as inferior rate capability. In this work, we synthesized a tin-based metal-organic framework (Sn-MOF) precursor at room temperature and subsequently transformed it via annealing treatment into a heterostructure Sn-SnO₂/Sn₂O₃@C composites. This self-sacrificing MOF-derived strategy yields a material featuring both a conductive carbon coating and an integrated SnO₂/Sn₂O₃ heterostructure, which collectively enhance electronic conductivity and mitigate volume expansion. Benefiting from the synergistic effect between the carbon matrix and the heterointerface, the anode material exhibits excellent electrochemical performance. Electrochemical tests demonstrate that the anode material presents a high reversible capacity (1242 mAh g^-1 at 0.1C), and its first-cycle coulombic efficiency reached 80.4%, a remarkable rate capability (501 mAh g^-1 at 5C), and a high lithium-ion diffusion coefficient. Furthermore, the electrode retains a capacity of 800 mAh g^-1 after 800 cycles at 500 mA g^-1. This work establishes an effective heterointerface engineering approach and offers a viable design strategy for fabricating Sn-based anode materials that combine long-term cycling stability with high-rate capability.