The electrolyte system of LiPF6 in propylene carbonate (PC) + diethyl carbonate (DEC) was measured for its electrolytic conductivity K at salt molalities in, solvent compositions w, and temperatures 0 in the ranges of (0.2, 2.4) mol kg(-1), (0, 0.7) mass fraction of DEC, and (-80, 60) degreesC, respectively, and for its glass transition temperatures T-g in the same ranges of in and w. The measured k-(m, w) data at different 0 were further fitted with an extended version of the Casteel-Amis equation in order to observe the change of K with simultaneous changes of in and w and with theta. The K surfaces according to these fitted equations all assumed a "dome" shape as a result of K peaking in both in and w. Furthermore, as theta lowered, these domes fell in height and shifted in the direction of low in and high w, the direction of lower viscosity eta. The Tg was found to rise with in and fall with w, indicating a concurrent change in the 71 of the solution. The measured K-T data were fitted with the Vogel-Fulcher-Tammann equation for an evaluation of the vanishing mobility temperature T-0 and the apparent activation energy E, for the electrolytes, both shown to form simple surfaces in the mw-coordinates slanting up in the direction of higher eta. Furthermore, when compared to the surface of T-g that of T-0 was oriented similarly but lower in value by more than 10 K.
