• Almeida, A.
• Pocrifka, La
• Passos, Rr
• Ruiz, Yl
• Aguilera, L.
• Moreira, Ja
• Aguiar, Pcm

Abstract

In this work, gamma-CoOOH was successfully synthesized from alpha-Co(OH)(2), as a precursor, by electrochemical oxidation, without the use of any additives or high temperatures. The films were morphologically and structurally characterized using X-Ray Diffraction and Scanning Electronic Microscopy techniques. Cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy techniques were used for the electrochemical characterization. The XRD and Raman techniques allowed confirming the effective conversion of alpha-Co(OH)(2) to gamma-CoOOH. The gamma-CoOOH films are composed of hexagonal platelets on a steel plate substrate. The deposited films exhibit excellent electrochemical performance at different current densities, and good cycling stability of 95.1% after 2000 cycles of charge/discharge. The maximum specific capacity of 89.3 mA h g(-1) was achieved at a current density of 1 mA g(-1). The results suggest a simple route to synthesize gamma-CoOOH films, which are promising as an electrode material for application in energy storage devices.

Topics

• density
• impedance spectroscopy
• x-ray diffraction
• steel
• current density
• cyclic voltammetry
• microscopy