The electrochemistry of lead dioxide formed on lead and lead alloys in sulphuric acid
Sheila K.M. Kelly
2134/7376
https://repository.lboro.ac.uk/articles/thesis/The_electrochemistry_of_lead_dioxide_formed_on_lead_and_lead_alloys_in_sulphuric_acid/9398270
The electrochemistry of lead dioxide has been studied using
the techniques of linear sweep voltammetry, potentiostatic pulse
experiments and a.c. impedance measurements. A morphological
examination was also carried out using the technique of scanning
electron microscopy. The formation of lead dioxide was investigated
on both the flat lead/lead alloy electrode and the porous electrode
which was produced by oxidation of a standard automotive positive
paste on a lead/lead alloy base. The electrochemistry of the pure
lead electrode (both flat and porous) was investigated and the
effect on this of various alloy additions was observed. The alloys
used, all of potential industrial importance, were lead-antimony,
lead-bismuth, lead-calcium-tin and lead-calcium-tin-bismuth at
various levels of bismuth addition. An a. c. study of Pb-Ca-Sn-Mg-Al
is also included.
The effect of antimony addition to lead has been isolated
as the production of a secondary oxidation layer. This provides
an explanation for the superior active material retention of antimony
containing grids in the lead-acid battery, the relatively large
material development with the antimonial alloy giving rise to a more
mechanically sound function between grid and paste. The formation
of this extra corrosion layer on antimonial lead may also explain
the high degree of top bar corrosion which occurs in the oxygen region
of the battery. The commercial significance of bismuth as a grid alloying
ingredient has been highlighted and'a useful bismuth concentration
range determined for both lead and lead-calcium-tin alloys.
2010-11-26 10:11:48
untagged
Chemical Sciences not elsewhere classified