  Ionic Liquids (ILs) are organic molten salts characterized by the total
absence of solvent. They show remarkable properties: low vapor pressure, high
ionic conductivity, high chemical, thermal and electrochemical stability. These
electrolytes meet therefore key criteria for the development of safe energy
storage systems. Due to a competition between electrostatic and van der Walls
interactions, ILs show an uncommon property for neat bulk liquids: they
self-organize in transient nanometric domains. In ILs-based electrochemical
devices, this fluctuating nano-segregation acts as energy barriers to the long
range diffusional processes and hence to the ionic conductivity. Here, we show
how the ionic conductivity of ILs can be increased by more than one order of
magnitude by exploiting one dimensional (1D) confinement effects in
macroscopically oriented carbon nanotube (CNT) membranes. We identify 1D CNT
membranes as promising separators for high instant power batteries.
