Pseudocapacitive Properties of Nano-structured Anhydrous Ruthenium Oxide Thin Film Prepared by Electrostatic Spray Deposition and Electrochemical Lithiation/Delithiation
✍ Scribed by S.-H. Park; J.-Y. Kim; K.-B. Kim
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 509 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1615-6846
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✦ Synopsis
Abstract
Nano‐structured anhydrous ruthenium oxide (RuO~2~) thin films were prepared using an electrostatic spray deposition (ESD) technique followed by electrochemical lithiation and delithiation. During the electrochemical lithiation process, RuO~2~ decomposed to nano‐structured metallic ruthenium Ru with the concomitant formation of Li~2~O. Nano‐structured RuO~2~ was formed upon subsequent electrochemical extraction of Li from the Ru/Li~2~O nanocomposite. Electrochemical lithiation/deliathiation at different charge/discharge rates (C‐rate) was used to control the nano‐structure of the anhydrous RuO~2~. Electrochemical lithiation/delithiation of the RuO~2~ thin film electrode at different C‐rates was closely related to the specific capacitance and high rate capability of the nano‐structured anhydrous RuO~2~ thin film. Nano‐structured RuO~2~ thin films prepared by electrochemical lithiation and delithiation at 2__C__ rate showed the highest specific capacitance of 653 F g^–1^ at 20 mV s^–1^, which is more than two times higher than the specific capacitance of 269 F g^–1^ for the as‐prepared RuO~2~. In addition, it showed 14% loss in specific capacitance from 653 F g^–1^ at 20 mV s^–1^ to 559 F g^–1^ at 200 mV s^–1^, indicating significant improvement in the high rate capability compared to the 26% loss of specific capacitance of the as‐prepared RuO~2~ electrode from 269 F g^–1^ at 20 mV s^–1^ to 198 F g^–1^ at 200 mV s^–1^ for the same change in scan rate.