Flexible and Conductive MXene Films and Nanocomposites with High Capacitance

Two-dimensional transition metal carbides (MXenes) offer a quite unique combination of excellent mechanical properties, hydrophilic surfaces, and metallic conductivity. MXenes, a new family of 2D materials, combine hydrophilic surfaces with metallic conductivity. Delamination of MXene produces single-layer nanosheets with thickness of about a nanometer and lateral size of the order of micrometers. With the exception of graphene, to date, few 2D materials have been made into highly flexible free-standing films with good electrical conductivities. Other 2D materials have been made into free-standing hybrids by the addition of conductive carbon nanotubes or graphene. Ab initio simulations predict elastic moduli along the basal plane to be over 500 GPa for various MXenes, suggesting that they could be useful reinforcements for polymer composites. Their excellent intrinsic conductivity, in combination with their reactive and hydrophilic surfaces, also renders them attractive as fillers in a number of polymers.