Ti3C2TX/ CMK-5 Nanocomposite as Sheet-like Anode ForLlithium Batteries

Lithium ion batteries have great importance for portable electronic devices and stationary energy storage because they are rechargeable power sources, with high power, high energy density and long cycling life [1-3]. Ti3C2TX nanosheets were prepared according to their related Ti3SiC2 MAX phase. Ten grams of Ti3SiC2 sample, was immersed in 50 wt.% HF solution under magnetic stirring. After washing, the powders were dried. The as-obtained d-MXene powder mixed with CMK-5 in equal weight and disperse in water/ethanol (1and was subjected to high energy ball milling. Cells were assembled in an Argon filled glove box using Ti3C2TX, Ti3C2TX/CMK-5 nanocomposite and lithium foil as reference electrode. It can be seen from Figure 1a that completely exfoliation performed and two-dimensional layered MXene was created. As seen in Figure 1b, when the Ti3C2TX and CMK-5 nanoparticles were milled, CMK-5 can effectively hinder the aggregation of the individual Ti3C2TX sheet by the shear force of zirconia balls and CMK-5 nanoparticles. Figure 1 . SEM images a) Ti3C2TX and b) Ti3C2TX/CMK-5 13th Annual Electrochemistry Seminar of Iran Materials and Energy Research Center (MERC), 22- 23 Nov, 2017 127 Figure 2a shows voltage- capacity dependence profiles for Ti3C2TX and Ti3C2TX/CMK-5 nanocomposite at 0.1C. For the Ti3C2TX/CMK-5 electrode, the initial discharge and charge capacities were 1035.9 mAh g-1 and 576.6 mAh g-1, respectively. The first cycle irreversibility and initial capacity drop can be ascribed as SEI layer formation and irreversible reduction of electrochemically active surface groups. Figure 2b displays cycling performance of Ti3C2TX/CMK-5 and Ti3C2TX electrodes at 1C. The Ti3C2TX/CMK-5 electrode shows the capacity of 342 mAh g−1 after 100 cycles with a coulombic efficiency of 98.6%. The voltage- capacity dependence profiles of Ti3C2TX /CMK-5 nanocomposite as an anode in Li- ion cell at different C rates are shown in Figure 2c. As seen, by increasing current rates, the capacity decreased, however gradually. Figure 2. a) Voltage profiles of the Ti3C2TX /CMK-5 composite and pristine Ti3C2TX at 0.1 C b) Cycling stability of pristine Ti3C2TX and Ti3C2TX /CMK-5 composite at 1C and (c) voltage profiles of Ti3C2TX /CMK-5 electrode at different cycling rates. Our results revealed that Ti3C2TX/CMK-5 nanocomposite with fast and simple method production, by improving in all MXene- based materials, can show high capacity and excellent rate capability and make it a suitable candidate for energy storage devices or other applications.