Facile synthesis and capacitive characteristics of Co(OH)2 nanoflakes via a solid-reaction route at room temperature

Flake-like beta-Co(OH)(2) with dimension around 20-50 nm was conveniently synthesized via a simple, low cost and practical room-temperature solid-state reaction with the assistance of polyethylene glycol (PEG) 400 and its electrochemical properties were evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge technology. A high specific capacitance of 658.4 F g(-1) at 5 mA was observed for the beta-Co(OH)(2) nanoflakes, compared to 302.7 F g(-1) for the block-like beta-Co(OH)(2) obtained without the PEG-400, showing the morphological function of nanoflakes for improving the capacitive performance. Furthermore, the beta-Co (OH)(2) nanoflakes can offer a good specific capacitance retention of ca. 80% after 1000 cycles, suggesting its potential application in supercapacitors. (C) 2011 Elsevier B.V. All rights reserved.