Si@Ti₃C₂T_x with Si nanoparticles embedded in a 3D conductive network of crumpled Ti₃C₂T_x nanosheets for the anode of lithium-ion batteries with enhanced cycling performance

Silicon-based materials are considered the most promising anode materials for lithium-ion batteries (LIBs). However, due to the huge volume effect of Si powder during charging and discharging, the pulverization and peeling of silicon nanoparticles results in a certain amount of active material loss, which significantly affects the stability and coulombic efficiency of the battery. In this paper, a simple suspension mixing-freeze drying process was used to prepare a Si@Ti₃C₂T_x composite with a fluffy and porous structure, in which Si nanoparticles (SiNPs) are wrapped in a 3D conductive network of wrinkled and curled Ti₃C₂T_x nanosheets. Thus, both Si nanoparticle agglomeration and restacking of Ti₃C₂T_x nanosheets are inhibited, electrolyte penetration and charge transfer are facilitated, and Si nanoparticle volume expansion is effectively buffered. When used as an LIB anode, after 500 cycles and at a density of 1 A g⁻¹, a high specific capacity of 1729 mAh g⁻¹ and coulombic efficiency of ≥ 98.5% were achieved for Si@Ti₃C₂T_x, showing excellent electrochemical performance.