Chapter 5 - Leady Oxide

Abstract

This chapter examines the importance of leady oxide in lead–acid batteries. Industrial experience has shown that the effect of leady oxide parameters is much stronger on the performance of positive plates than on the negatives. Thus, the properties of the leady oxide eventually affect battery performance. Leady oxides (PbO) with very fine-grained structure yield high initial capacity, which then declines very soon. PbO exists in two modifications (polymorphs): red tetragonal lead oxide that is stable at low temperatures and low pressures and yellow orthorhombic lead oxide that has a layered structure, built of infinite PbeO chains. Lead for the battery industry is derived from ores mined in different parts of the world or is obtained by recycling of used up batteries that have reached their end of life. When leady oxides with different particle size distribution, specific surface and phase composition are used as starting material for paste preparation, they will require different amounts of sulfuric acid and different conditions of preparation of the pastes so as to yield active materials of high power and capacity performance characteristics, as demanded for the different battery applications. Though lead oxide is only a starting compound for a number of chemical processes, it exerts an influence on the energetic and capacity performance parameters of lead–acid cells and batteries. Hence, it is essential to produce leady oxides with optimum and stable physico-chemical properties, which would guarantee high battery performance.