پديدآورندگان :
Sovizi Mohammad Reza mrsovizi@mut.ac.ir Malek Ashtar University of Technology , Pourali Zeinab mrsovizi@mut.ac.ir University of Zanjan , Yaftian Mohammad Reza mrsovizi@mut.ac.ir University of Zanjan
كليدواژه :
Lithium Batteries , Mxenes , Nanocomposite , Cycle Performance
چكيده فارسي :
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
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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.
