First Electrodeposition of Silicon on Crumbled MXene (c-Ti3C2Tx) for High-Performance Lithium-Ion Battery Negative Electrode

The demand for high energy density Li-ion batteries requires electrode materials with high capacity and long cycling stability. Silicon is among the most promising negative electrode materials due to its high theoretical capacity, abundant resources, and low working potential. However, its poor conductivity and significant volume expansion during cycling limit its practical application. To overcome these issues, this study develops a two-step synthesis method for a nanostructured composite based on silicon as the active material. First, a crumbled Ti₃C₂T_x (c-Ti₃C₂T_x) structure formed through electrostatic interaction between a Ti₃C₂T_x suspension and 1 M KOH. Then, an amorphous silicon layer is electrodeposited onto the c-Ti₃C₂T_x flakes in a room-temperature ionic liquid, creating the Si/c-Ti₃C₂T_x composite for the negative electrode of Li-ion batteries. The c-Ti₃C₂T_x structure enhances conductivity, provides mechanical stability to accommodate silicon's expansion, and offers nanostructured porosity for lithium-ion diffusion. The composite material demonstrates exceptional cycling stability, achieving a capacity of 1300 mAh g⁻¹ at C/5 with 91 % capacity retention after 100 cycles.