Organogel Electrolytes Based on a Low Molecular Weight Gelator: 2,3-Bis(<i>n</i>-decyloxy)anthracene

Abstract

Since 2,3-bis(n-decyloxy)anthracene (DDOA) is a good gelling agent for a large number of solvents including propylene carbonate (PC), the electrochemical properties of organogel electrolytes based on DDOA have been investigated. The presence of tetraalkylammonium salts in DDOA/PC gels is shown to preserve the three-dimensional network of DDOA fibers. In addition, at a given temperature, the conductivity is practically the same in the gel as in the corresponding solution with or without DDOA. The gelation temperature, Tgel, is slightly affected by the presence and nature of the salt. Thus, at 1M salt concentration, Tgel is increased by 9 °C with Et4NBF4 and decreased by 7 °C with Bu4NBF4, presumably because of a surfactant effect of the Bu4N+ cation. The electrochemical stability window of the liquid electrolyte is limited by the stability of DDOA, which displays the typical redox behavior of anthracene. However, in the gel state, DDOA is apparently protected within the fibers and the electrochemical stability extends up to 3 V. The performances of a DDOA gel electrolyte have been tested in a carbon double-layer capacitor.