Binder-free Co(OH)2 nanoflake-ITO nanowire heterostructured electrodes for electrochemical energy storage with improved high-rate capabilities

Abstract

We present the fabrication of binder-free Co(OH)2 nanoflake-ITO nanowire heterostructured electrodes via a combination of chemical vapor deposition and electrodeposition methods for electrochemical energy storage applications. Detailed studies showed that the specific capacitance retention capabilities of these hybrid electrodes were greatly enhanced in comparison to electrodes without nanowire augmentation. The improvement was further verified by our statistical studies of electrodes with loading masses in the range of 0-500 μg cm-2. The highly conductive ITO nanowires can serve as direct electron paths during the charge/discharge process, facilitating the full utilization of electroactive materials. These rigid oxide nanowire supports enable facile and uniform surface coating and are expected to be more stable than previous composite electrodes based on carbon nanotubes. This study provides a promising architecture for binder-free electrochemical capacitors with excellent capacitance retention capabilities. © 2011 The Royal Society of Chemistry.