Effects of Cyclic Structure of Ammonium Ions on Capacitance in Electrochemical Double Layer Supercapacitors

Abstract

The conductivity of the electrolyte used plays a critical role in the optimization of the performance of electrochemical double layer capacitors. However, when the difference in the conductivities of different electrolytes is not significant (only 10-20%), the conductivity has little effect on the capacitance. On the other, unlike the conductivity and viscosity of the electrolyte, the cation size directly influences the capacitance. Cyclic ions have a smaller effective radius than that of the corresponding acyclic ions because the acyclic alkyl groups have a greater number of conformational degrees of freedom, such as the rotational, bending, and stretching modes. Consequently, because of the smaller effective size of the cyclic ions, cells containing electrolytes with such ions exhibit higher capacitances than do those with their acyclic counterparts.

A New 2-Aminospiropyrazolylammonium Cation with Possible Uses in the Topical Areas of Ionic Liquids

“…A non-aqueous electrolyte consists of an ionic liquid in which the anion is bis((trifluoromethyl)sulfonyl)methanide [N(SO 2 CF 3 ) 2 ] − , and the cation includes Mg 2+ and an organic onium cation-of 5-azoniaspiro- Quaternary ammonium tetrafluoroborate (QA BF4) salts are highly soluble in nonaqueous solvents, conferring high conductivity [104]. Two series of tetrafluoroborates (C80, C6, and C60 and C8, C9, and C10) have been synthesized so that the cations of each series had almost the same molecular weight, with the number of carbon atoms being 6, 8, and 10; however, different structures were achieved in terms of whether it is cyclic or not (Figure 5) [105]. The experiment was performed using acetonitrile on carbon catalysts with a 40 µ thick cellulose separator that was placed between the two electrodes Quaternary ammonium tetrafluoroborate (QA BF 4 ) salts are highly soluble in nonaqueous solvents, conferring high conductivity [104].…”

“…The experiment was performed using acetonitrile on carbon catalysts with a 40 µ thick cellulose separator that was placed between the two electrodes nonaqueous solvents, conferring high conductivity [104]. Two series of tetrafluoroborates (C80, C6, and C60 and C8, C9, and C10) have been synthesized so that the cations of each series had almost the same molecular weight, with the number of carbon atoms being 6, 8, and 10; however, different structures were achieved in terms of whether it is cyclic or not (Figure 5) [105]. The experiment was performed using acetonitrile on carbon catalysts with a 40 µ thick cellulose separator that was placed between the two electrodes The effect of the presence of a cyclic structure and its size on the conductivity of the electrolyte has been tested.…”