2-dimensional metal carbide and nitride materials (MXene) with controlled Cl-and Osurface terminations (MS-Ti3C2Tx) were prepared from a molten salt etching route and their electrochemical properties were investigated in nitrile-based electrolytes. Results show that the power performance of MS-Ti3C2Tx was greatly improved in acetonitrile (ACN) based non-aqueous organic electrolytes, which are conventional electrolytes for electrochemical capacitors. The addition of lithium salt to reach 2 M LiTFSI in ACN results in the increase of the specific capacitance. Moreover, replacing LiTFSI with LiFSI drastically improves the power performance of MXene at a high scan rate (95 mAh g-1 at 900C). These results highlight the importance of properly matching the electrolyte composition to the electrode material and shed light on MXenes materials as high-rate electrodes for energy storage applications.