Nonaqueous liquid electrolytes, double-layer

For commercial double-layer capacitors using activated carbon electrodes, a nonaqueous solution such as 0.5 to 1 mol dm (=M) Et4NBp4 in propylene carbonate (PC) or an aqueous solution such as 3.7 to 4.5 M (30 35 wt%) H2SO4 is used. The advantages of the nonaqueous liquid electrolytes are as follows ... 

Based on these properties, the double-layer capacitor comprising from a pair of the activated carbon electrodes and the nonaqueous liquid electrolyte is the most favorable one from the viewpoint of energy density. Ionic liquids are a kind of nonaqueous liquid electrolytes. 

The discussion of the relative stability of solutions with inverse micelles and of liquid crystals containing electrolytes may be limited to the enthalpic contributions to the total free energy. The experimentally determined entropy differences between an inverse micellar phase and a lamellar liquid crystalline phase are small (12). The interparticle interaction from the Van der Waals forces is small (5) it is obvious that changes in them owing to added electrolyte may be neglected. The contribution from the compression of the diffuse electric double layer is also small in a nonaqueous medium (II) and their modification owing to added electrolyte may be considered less important. It appears justified to limit the discussion to modifications of the intramicellar forces. 

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