Cation Intercalation and High Volumetric Capacitance of Two-Dimensional Titanium Carbide

摘要: The intercalation of ions into layered compounds has long been exploited in energy storage devices such as batteries and electrochemical capacitors. However, few host materials are known for much larger than lithium. We demonstrate the spontaneous cations from aqueous salt solutions between two-dimensional (2D) Ti3C2 MXene layers. MXenes combine 2D conductive carbide layers with a hydrophilic, primarily hydroxyl-terminated surface. A variety cations, including Na+, K+, NH4+, Mg2+, Al3+, can also be intercalated electrochemically, offering capacitance excess 300 farads per cubic centimeter (much higher that porous carbons). This study provides basis exploring large family carbides carbonitrides applications using single- multivalent ions.