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Electrolytes are an important component in determining the performance and cycle life of ultracapacitors. Good electrolytes should have high ionic conductivity, large electrochemical windows, and excellent thermal and chemical stability. Ionic liquids are possibly ideal electrolytes to satisfy these requirements. In the present work, we developed easy-to-use methods to incorporate ionic liquids into a polymer matrix to synthesize gel polymer electrolytes ͑GPEs͒. Combining the advantages of both the ionic liquids and the conventional GPEs, the resultant solid-state ionic liquid-incorporated gel polymer electrolytes ͑ILGPEs͒ possess better properties than these two components considered individually. Our synthesized ILGPE films are flexible and mechanically strong and have a wide electrochemical window of 4 V, a high ionic conductivity up to 3.5 mS/cm ͑at room temperature͒, and a high thermal stability up to 350°C. These ILGPEs have been used to fabricate solid-state ultracapacitors that demonstrate improved performance and cycle life.

A new experimental technique has been developed for the study of the dynamic tensile strength of liquids, The liquid is confined between a solid plate and a stretched aluminized Mylar film, Pulsed electron beam deposition in the plate generates a stress wave which traverses the liquid and gives a high tensile stress during reflection at the Mylar-covered free surface, Interferometric analysis of the motion of the Mylar film provides a sensitive measure of the stress-wave-liquid interaction, The technique has been used to determine a dynamic tensile strength for glycerol at room temperature of O.6±O.1 kbar from 5 to 23 kbar//Lsec. No variation of tensile strength with stress rate was found.

This paper presents a method for overcoming temperature and pressure limitations inherent in conventional techniques for measuring equilibrium thermodynamic data. The method can be applied to conducting materials that can be resistively heated and that do not dissociate in the liquid phase; and it is thus particularly suitable for investigating pure liquid-metal thermodynamic data. The technique has been applied extensively to lead at temperatures exceeding 5000 K and at pressures up to 2 kilobars. A cylindrical material specimen 1 mm in diameter and 25 mm long is interposed between two current leads and mounted axially concentric with a high-pressure cell. After the cell is pressurized with helium, a current pulse from the overdamped discharge of a high-voltage capacitor bank heats the wire at such a rate that its expansion is nearly isobaric. The energy deposited in a central segment of the sample is computed by integrating the product of the current flowing in the segment with the resistive voltage developed across it. With these data, sample resistance can also be calculated during a major portion of the time that current flows. Because mounting constraints limit sample expansion to the radial dimension, the equilibrium volume is calculated from the expanded diameter, which is measured by means of pulsed x-radiography.

Electrodes and electrolytes are two essential components of a supercapacitor and play important roles in determining the performance for the supercapacitor. In the present work, we investigated the electrochemical and capacitive behavior of aligned carbon nanotube electrodes in ionic liquid electrolytes to study the feasibility to develop high performance supercapacitors from these two components. Synthesis procedure of the carbon nanotubes and composition of the ionic liquids have been studied to achieve a high capacitance and fast charge/discharge process for the carbon nanotube electrode in the ionic liquid electrolyte.