Synergistic confinement by MOF-derived carbon and MXene in silicon-based anodes enables stable lithium storage

Silicon-based anodes offer high theoretical capacity for lithium-ion batteries but suffer from severe volume expansion during cycling, leading to structural degradation and capacity fade. This study presents a novel Si/SiO_x@C@MXene composite to overcome these limitations through the synergistic confinement by the metal-organic-framework (MOF) derived carbon and MXene. The resulted Si/SiO_x@C@MXene composite features a unique architecture where MOF-derived carbon-coated Si/SiO_x nanospheres are embedded within or anchored onto the conductive MXene sheets, forming a robust three-dimensional sandwich-like structure. Electrochemical test reveal that Si/SiO_x@C@MXene delivers a high initial discharge capacity of 1158.0 mAh g⁻¹ at 100 mA g⁻¹, maintains 953.5 mAh g⁻¹ after 1000 cycles at 1000 mA g⁻¹ (84.9 % capacity retention), and exhibits excellent rate capability (543.9 mAh g⁻¹ at 5000 mA g⁻¹). This work highlights the effectiveness approach for developing high-performance, stable silicon-based anodes.