Acta Phys. -Chim. Sin. ›› 2013, Vol. 29 ›› Issue (05): 1013-1020.doi: 10.3866/PKU.WHXB201303122

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

Fabrication and Performance of Electrolytic-Electrochemical Hybrid Capacitors

YANG Bin, WU Hui, HU Song-Wei, LÜ Hui-Ling, SONG Ye, ZHU Xu-Fei   

  1. Key Laboratory of Soft Chemistry and Functional Materials of Education Ministry, Nanjing University of Science and Technology, Nanjing 210094, P. R. China
  • Received:2013-01-21 Revised:2013-03-11 Published:2013-04-24
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51077072, 61171043).

Abstract:

To solve the issue of comparatively low operation voltage of electrochemical capacitors, a hybrid capacitor consisting of the anode electrode of tantalum electrolytic capacitor and the cathode electrode of polyaniline (PANI)/TiO2 with high energy density and high working voltage was developed. The PANI/TiO2 composite electrode for use as the capacitor cathode was prepared by in situ electrochemical polymerization of aniline in porous anodic titania nanotube arrays on titanium foil substrates. The composite electrode showed good rate capability with a specific capacitance of 10.0 mF·cm-2 and a high power density of 0.55 mW·cm-2. Using a dielectric coated anode electrode, the single-cell hybrid capacitor could withstand working voltages as high as 100 V. As the PANI/TiO2 composite cathode only requires a small volume because of its high specific capacitance, available space can be used to enlarge the anode electrode, leading to an increase in specific capacitance of the hybrid capacitor. The hybrid capacitor had high volumetric and gravimetric energy densities, which were about four times and three times higher than those of a tantalum electrolytic capacitor. The short circuit charge-discharge cycle test for the hybrid capacitor at 100 V showed that its capacitance did not decrease, and the equivalent series resistance did not increase after 10000 cycles, indicating excellent cycle stability and power performance. The peak power density was estimated to be 847.5 W·g-1. In addition, electrochemical impedance spectroscopy data indicated that the hybrid capacitor had good impedance and frequency characteristics.

Key words: Hybrid capacitor, Electrochemical capacitor, TiO2, Polyaniline, Tantalum electrolytic capacitor

MSC2000: 

  • O646