Robust MXene Adding Enables the Stable Interface of Silicon Anodes for High-Performance Li-ion Batteries

Silicon (Si)-based materials were considered to be the most promising anodes for next-generation lithium-ion batteries because of their high theoretical specific capacity. However, huge volume expansion during lithiation/de-lithiation processes and low electrical conductivity cause its rapid degradation. Most research has focused on the modification of Si, binders, and electrolytes, however, little attention has been paid to conductive additives, a small but extremely important component of lithium-ion battery materials. Herein, 2D MXene nanosheet owing to excellent electrical conductivity is used as the conductive additive to improve the capacity and cycle performance of Si anodes. As a result, the Si-M1 electrode demonstrates a discharge specific capacity of 2522.6 mAh/g at a current density of 1A/g after 100 cycles and 1867.1 mAh.g(-1) at 5A/g. In this regard, good electrical contact was maintained, along with the inhabiting generation of dead Si attributed to the volume effect that was suppressed by MXene. Besides, the terminal groups of MXene are conducive to the formation of materials with good conductivity in solid electrolyte interphase. This new insight may contribute to promoting the application of Si anodes and promising extended to other anodes living with huge volume expansion.