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6
Lead Oxides

Dietrich Berndt

6.1
Introduction

Lead oxides play an important role in lead–acid batteries.

• Lead dioxide (PbO 2 ) forms the charged state of the active material in the positive
electrode.
• Lead oxide (PbO) (also called litharge) is formed when the lead surface is exposed
to oxygen. Furthermore, it is important as a primary product in the manufacturing
process of the active material for the positive and negative electrodes. It is not
stable in acidic solution but it is formed as an intermediate layer between lead
and lead dioxide at the surface of the corroding grid in the positive electrode. It is
also observed underneath lead sulfate layers at the surface of the positive active
material.
• Minium (Pb 3 O 4 ) represents a more highly oxidized form of lead oxide that
enhances the electrochemical oxidation of lead oxide to lead dioxide.
The history of the lead–acid battery goes back to 1854 when Sinsteden published
performance data on this battery system for the first time (cf. Ref. [1]). The practical
importance of the lead–acid battery system was detected, in 1859, independently
of Sinsteden’s work, by Plant´ e, who produced a rechargeable battery by alternately
charging and discharging lead sheets immersed in sulfuric acid [2]. Lead dioxide
(PbO 2 ) as the ‘active material’ is thereby directly generated from lead that is used as
the conducting substrate. Plant´ e plates are still in use, and are in principle produced
by this method [3]. Separate production of the active material was introduced by
Faur´ e in 1881. It is the basis of the pasted-plate design, mainly used today.
Since those early days, the lead–acid battery has always been the most impor-
tant rechargeable electrochemical storage system, maintaining its prime position
unchallenged now for more than a century. This seems surprising, because the
fundamental data concerning the amount of energy that can be stored are rather
modest on account of the high weight of the reacting substances. One main reason
is the comparatively moderate price of lead–acid batteries. But besides that, there

Handbook of Battery Materials, Second Edition. Edited by Claus Daniel and J¨ urgen O. Besenhard.
 2011 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2011 by Wiley-VCH Verlag GmbH & Co. KGaA.