PREPARATION OF NICKEL - COBALT SPINEL OXIDES NixCO3-xO4.COMPARISON OF TWO PHYSICAL PROPERTIES STEMMING FROM FOUR DIFFERENT PREPARATION METHODS AND USING CARBON PASTE ELECTRODE

Abstract

A comparative study of two electro-physical properties (porosity and electrical conductivity) of binary nickel cobalt oxides electrodes with spinels mixed oxides Ni_xCo_3-xO₄ as active matter, was carried out. Four different routes were used to prepare spinel-type Ni_xCo_3-xO₄ (0 ≤ x ≤ 2.5) compounds in order to link these properties with the preparation method. The substitution of Ni for Co increases the conductivity and the porosity of the electrode till a certain ratio of nickel. X-ray diffraction patterns showed that the oxides crystallize in a cubic spinel phase. Electrical conductivity as well as porosity depends on the preparation route.

KEY WORDS: Nickel cobalt spinel oxides, Porosity, Electrical conductivity, Mixed oxides electrodes, Carbon paste electrode, Pechini sol-gel method


Bull. Chem. Soc. Ethiop. 2007, 21(2), 255-262.