A novel “plane-line-plane” nanostructure of the sandwich-like CNTs@SnO2/Ti3C2Tx 3D nanocomposite as a promising anode for lithium-ion batteries

As one of the novel two-dimensional metal carbides, Ti3C2Tx has received intense attention for lithium-ion batteries. However, Ti3C2Tx has low intrinsic capacity due to the fact that the surface functionalization of F and OH blocks Li ion transport. Herein a novel “plane-line-plane” three-dimensional (3D) nanostructure is designed and created by introducing the carbon nanotubes (CNTs) and SnO2 nanoparticles to Ti3C2Tx via a simple hydrothermal method. Due to the capacitance contribution of SnO2 as well as the buffer role of CNTs, the as-fabricated sandwich-like CNTs@SnO2/Ti3C2Tx nanocomposite shows high lithium ion storage capabilities, excellent rate capability and superior cyclic stability. The galvanostatic electrochemical measurements indicate that the nanocomposite exhibits a superior capacity of 604.1 mAh g−1 at 0.05 A g−1, which is higher than that of raw Ti3C2Tx (404.9 mAh g−1). Even at 3 A g−1, it retains a stable capacity (91.7 mAh g−1). This capacity is almost 5.6 times higher than that of Ti3C2Tx (16.6 mAh g−1) and 58 times higher than that of SnO2/Ti3C2Tx (1.6 mAh g−1). Additionally, the capacity of CNTs@SnO2/Ti3C2Tx for the 50th cycle is 180.1 mAh g−1 at 0.5 A g−1, also higher than that of Ti3C2Tx (117.2 mAh g−1) and SnO2/Ti3C2Tx (65.8 mAh g−1), respectively.