40 u03bcm thick separator membrane this two cell single packaged device has a volume in the order of 1 14 u00d7 10 u2212 6 m 3 and a weight of 1 09 g the conductivity of 1m mteatfb in pn was measured at a range of temperatures and compared with corresponding values for 1m teatfb in an the results are shown in fig1 where it can be seen that the conductivity of the electrolyte mteatfb in pn is lower than that for teatfb in an across a wide range of temperatures the conductivity of mteatfb in pn at 23 u00b0 c was measured at a variety of concentrations and again compared with corresponding values for teatfb in an at 23 u00b0 c the results are shown in fig2 where it can be seen that the conductivity of mteatfb pn is dependent upon mteatfb concentration for any given salt concentration mteatfb pn is lower than teatfb in an supercapacitors were prepared as described in the experimental section above one group of supercapacitors was filled with the state of the art electrolyte solution a solution of 1m teatfb in acetonitrile another group of supercapacitors was filled with 1m mteatfb in propionitrile effective capacitance ce for two identical dual cell devices discharged from 4 5v at 100 ma was determined where the only difference was the electrolyte the results are shown in fig3 the figure is limited to the time range 0 001 to 10 seconds but it can be appreciated that data extends to both shorter and longer time scales an initial voltage of 4 5v was chosen to allow direct comparison of the mteatfb pn device with the less voltage stable teatfb an device the esr rise rates of a mteatfb pn supercapacitor was compared with that of.