Structural design and investigation of Ti3C2 MXene as a conductive interlayer for improving the lithium-storage performance of PSi@C anode material

Abstract

Silicon stands out as an ideal anode material for the next generation of lithium-ion batteries (LIBs) due to its abundant sources, low lithiation/delithiation potential, and high specific capacity. However, its practical application is impeded by significant volume expansion, leading to electrode structure damage. In this study, the Porous silicon(PSi)@C/Ti₃C₂ MXene composite was developed by dispersing porous micro-silicon@carbon (PSi@C) particles into layered stackable Ti₃C₂ MXene sheets using ultrasonic and freeze drying. The Ti₃C₂ MXene interlayer played a crucial role in enhancing the conductive crosslinking network between PSi@C particles, and providing efficient channels for electron transport/ion diffusion. Additionally, the Ti₃C₂ MXene interlayer served as a buffer to accommodate the substantial volume changes in silicon during electrochemical cycling. Consequently, the PSi@C/Ti₃C₂ MXene composite electrode demonstrated rapid electron/ion conduction and maintained structural stability. Remarkably, the electrode exhibited outstanding long cycle stability with 952 mAh g^-1 at 0.5 A g^-1 after 200 cycles and excellent rate performance with 542 mAh g^-1 at 2 A g^-1.