Preparation And Electrochemical Performance Of Two-dimensional Carbide Crystals MXene

Supercapacitor and lithium ion battery are currently the most commonly used secondary storage device, they have high power density, high energy density, long life, good safety. Their electrochemical properties are related to the electrode materials. Two-dimensional crystal materials compared with its parent material have a lot of specific performances, especially the high specific surface area, make them became the candidates of electrode materials. In this article a novel two- dimensional(2D) carbide MXene was made by hydrofluoric acid etching Ti3AlC2, the influence factors of the preparation and thermal stability of MXene were also reaserched, and the MXene was used to prepared electrodes of supercapacitors or lithium ion battery cathode.Hydrophilic property and relatively low specific surface area of MXene make MXene-based supercapacitors have better electrochemical performance with KOH aqueous electrolyte than organic electrolyte. A high volumetric capacitance 119.8 F/cm3 was achieved at the current density of 2.5 A/g. It was found that carbon black improved the performance of capacitors. This was because carbon black avoided the preferred orientation of MXene, provided fast ion transport channels for the KOH aqueous and in turn, increased electrical conductivity.Electrochemical measurements showed a large lithiation and delithiation potential, which meaning that the charge storage in MXene material is due to the intercalation of Li+ ions and not due to a conversion reaction. It exhibited a stable capacity of 131 mAh g-1 at a 1C rate, this result suggest that MXene is a promising anode material for Li+ intercalation.In addition, High purity Ti2 SnC was synthesized from TiC/Sn /TiH2 or 2TiH2/Sn/C at 1400 °C for 1 h. High purity Ti2 AlC was successful synthesized by pressureless sintering from Ti C/1.1Al/TiH2 or 2Ti H2/1.1Al/C mixture powder at 1400 °C for 1 h. Ti3AlC2 reacted with AlTi to form Ti2 AlC was demonstrated.