Thieno[3,4-b]-1,4-oxathiane (EOTT), one asymmetrical analog of 3,4-ethylenedioxythiophene (EDOT), was synthesized and its chemical oxidative polymerization was carried out in different solvents (dichloromethane, water, and acetonitrile (CH2Cl2, H2O, and ACN)). The effect of the solvent on the structure, crystalline characteristic, morphology, and thermal stability of poly(thieno[3,4-b]-1,4-oxathiane) (PEOTT) were investigated by fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetry, respectively. PEOTT prepared from H2O exhibited higher electrical conductivity (similar to 10(0) S/cm) and more robust thermal stability. The electrochemical capacitance performance of PEOTT electrode in ACN-LiClO4 was initially found dissatisfactory. Furthermore, the electrochemical properties of this electrode in another three aqueous electrolytes (H2SO4, HClO4, and LiClO4) were also investigated comparatively by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy (EIS). It revealed the enhanced specific capacitance (208 F/g at 1 A/g) and improved capacitance retention (80.4% after 1000 cycles at 10 A/g) of PEOTT electrode in H2O-HClO4 compared to those of the electrode in ACN-LiClO4. These results implied that PEOTT employing aqueous HClO4 electrolyte should be a promising electrode material for supercapacitor applications. (C) 2015 Elsevier Ltd. All rights reserved.