Battery - lead acid composition

Fig. 5. Lead—Acid battery grid design variations showing A lugs, B feet, C frames, and D current carrying wire for (a) rectilinear design, (b) corner lug radial, (c) center lug radial, (d) corner lug expanded metal, and (e) plastic/lead composite.

The conductivity of the grid plays a substantial role in a battery s abiUty to meet high current demands. The importance of grid conductivity for lead—acid batteries has been discussed (1,69). Composition and configuration are important design factors impacting grid conductivity. 

R. T. Johnson and. R. Pierson, "The Impact of Grid Composition on the Performance Attributes of Lead—Acid Batteries," iu L. J. Pearce, ed.. Power Sources 11, International Power Sources Symposium Committee, 1987. 

Lead-acid batteries can be classified into three major types or categories, namely, automotive (SLI), stationary, and motive power (industrial). In addition, there are many special batteries that cannot be easily categorized as either of the above types. As these types of batteries are constructed with different materials and design to meet the requirements of their intended end uses, each requires a particular separator with specific material composition, mechanical design, and physical, chemical, and electrochemical properties that are tailored for the battery and its relevant specific uses. These batteries are generally available in flooded electrolyte or valve regulated (sealed) versions. In this section the types... 

Magneli phase TiO (x = 1.67 to 1.9) is conductive. A proprietary material of this composition in the form of solid sheets or a honeycomb has been patented for use as current-collectors in either monopolar or bipolar lead-acid batteries [15]. The honeycombed structure holds the paste and thereby improves paste adhesion and the mechanical stability of the plate, as well as the electrical conductivity. The material is stable at the potentials of the positive plate [16,17]. 

The beneficial effect of compression in extending the cycle-life of VRLA batteries was confirmed in a project carried out by the Advanced Lead-Acid Battery Consortium (ALABC) [17]. The work also showed that the composition of the micro-fine glass separator has an important influence on cycle-life, namely, a higher... 

Total life cycle analyses may be utilized to establish the relative environmental and human health impacts of battery systems over their entire lifetime, from the production of the raw materials to the ultimate disposal of the spent battery. The three most important factors determining the total life cycle impact appear to be battery composition, battery performance, and the degree to which spent batteries are recycled after their useful lifetime. This assessment examines both rechargeable and non-rechargeable batteries, and includes lead acid, nickel cadmium, nickel metal hydride, lithium ion, carbon zinc and alkaline manganese batteries. 

Finally, the conversion of the primary metal into the product and the form which are actually utilized in the battery system should be considered. For example, the electrode materials in lead acid batteries are normally cast lead or lead-alloy grids. The materials utilized in NiCd batteries are cadmium oxide and high surface area nickel foams or meshes. Technically, all of these factors should be considered to produce a detailed life cycle analysis. However, again, these differences are generally quite small compared to the principal variables - composition, performance and spent battery disposal option. 

The effect of phase composition of the pastes on the performance of lead-acid batteries has been studied by a number of authors. 

The active material comprises the substances that constitute the charge-discharge reaction. In the positive electrode of lead-acid batteries, the active material in the charged state is lead dioxide (PbOj), which is converted into lead sulfate (PbS04) when the electrode is discharged. The active material is the most essential part of a battery, and battery technology has to aim at optimum constitution and performance for the expected application. This does not only concern the chemical composition but also the physical structure and its stability. Specialized methods have been developed to fulfill these requirements, and the primary products as well as the manufacturing process are usually specified by the individual battery manufacturer. 

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