Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (03): 525-532.doi: 10.3866/PKU.WHXB201301091

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Application of Ionic Liquids with Carboxyl and Aromatic Ring Conjugated Anions in Dye-Sensitized Solar Cells

WANG Hai1,2,3, XU Xue-Qing1,2, SHI Ji-Fu1,2, XU Gang1,2   

  1. 1 Guangzhou Institute of Energy Conversion 510640, P. R. China;
    2 Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Science, Guangzhou 510640, P. R. China;
    3 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2012-10-25 Revised:2013-01-08 Published:2013-02-25
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21103194, 21273241), Pearl River Science and Technology New Star of Guangzhou, China (2012061), and Director Innovation Foundation of Guangzhou Institute of Energy Conversion of Chinese Academy of Sciences (y007r71001).


A method of utilizing p-π conjugation effects for obtaining low-viscosity ionic liquids is presented. p-π conjugation effectively disperses anionic charge and reduces Coulombic interactions. Ionic liquids prepared in this study were 1-ethyl-3-methylimidazolium benzoate (EMIB) and 1-ethyl-3- methylimidazolium isonicotinate (EMIIN). They have carboxyl and aromatic ring p-π conjugated anions, and achieve low viscosities of 42 and 27 mPa·s, respectively. EMIB and EMIIN were employed as electrolytes, which were used to construct dye-sensitized solar cells (DSCs). After optimizing the composition, the ionic conductivity and triiodide ionic diffusion constant for the EMIB-based electrolyte were 1.43 mS·cm-1 and 1.45 × 10-7 cm2·s-1, respectively. For the EMIIN-based electrolyte, the ionic conductivity and triiodide ionic diffusion constant were 1.63 mS·cm-1 and 2.01×10-7 cm2·s-1, respectively. These were higher than the corresponding values for the EMIB-based electrolyte because of EMIIN's lower viscosity. DSCs based on these two electrolytes attained satisfactory energy conversion efficiencies of 2.85% and 4.30% for EMIB and EMIIN, respectively, under an illumination intensity of 300 W·m-2.

Key words: Ionic liquid, Viscosity, Electrolyte, Conductivity, Dye-sensitized solar cell