Thin Film Supercapacitors Using a Sputtered RuO[sub 2] Electrode

Abstract
An all solid-state thin film supercapacitor (TFSC) was fabricated with an amorphous ruthenium oxide (RuO2)(RuO2) thin film electrode and an amorphous LixPOyNzLixPOyNz (Lipon) thin film electrolyte. The electrochemical behavior of the RuO2/Lipon/RuO2/PtTFSCRuO2/Lipon/RuO2/PtTFSC was characterized by a charge-discharge technique in the potential range of 0-2 V. The RuO2/Lipon/RuO2/PtTFSCRuO2/Lipon/RuO2/PtTFSC exhibited a behavior of a bulk-type supercapacitor, even though the capacity of an as-fabricated TFSC was found to be much lower than the bulk one and showed a rapid decrease in capacity. This can be explained by excess oxygen ions and interfacial structure modification. The discharge yield dropped by 53% after 500 cycles. The capacitance per volume of the RuO2/Lipon/RuO2/PtTFSCRuO2/Lipon/RuO2/PtTFSC at the first cycle is 38 mF/cm2 μm. © 2001 The Electrochemical Society. All rights reserved.
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