Etude du mécanisme de réduction de PbO2 : Application de l’électrode à microcavité.

Abstract

The storage of the electrical energy involves the use of electrochemical generators, although great efforts were made to find new electrochemical systems. Lead-acid battery which isdiscovered in 1860 by Planté still remains the most available and efficient generator, its mechanism is mainly based on PbO2 reduction into PbSO4. The investigation of the reduction of PbO2 using microcavity electrode confirms that the mechanism is a semi rapid diffusional system, the heating of the active positive mass(PAM) affects unfavorably the reduction capacity which supports the concept of gel-crystal system with electron-proton conductivity of hydrated gel zones. Doping PbO2 with metallic ions affects both composition and structural properties of the PAM. The results showed that the water amount present in gel zones and the discharge capacity depend mainly on the nature of the dopant. Enhanced capacity is observed with both tin and antimony doped samples.