Batteries components

Battery Average voltage/V Capacity/A h Weight/g Energy density/Wh kg  

The battery case must be resistant to corrosion from both inside and outside and, hence, must be stable to chemical attack by the electrolyte, active materials and the environment at the operating temperature. In addition, it must have the required mechanical strength, be cheap and light and have a simple method of sealing. 

For alkaline batteries, the case is generally steel, while for systems with an acid electrolyte, polypropylene is rapidly replacing materials such as hard rubber. For a few batteries, the case also acts as one of the active materials, e.g. the zinc can in a Leclanche cell. 

the separator must be stable chemically to the electrolyte and to the active materials at the temperature of operation. It is also necessary for the membrane 

In order for the battery to have an acceptable capacity, the active material is almost always a thick layer of a porous, particulate paste and the electronic conductivity of this material is seldom very high. Hence, it is necessary to have a current collector, which is usually a metal grid or sheet, to provide a conducting path through the paste and thereby minimize the resistance of the battery. The current collector also acts as a physical support for the active mass which otherwise would be a very brittle structure. 

Again the separator must be chemically stable to the electrolyte and to the active materials at the temperature of operation. It is also necessary for the membrane to have the correct qualities of wettability, selectivity, resistivity and flexibility for the particular battery system. The cost is very variable in lead/acid batteries the target would be pence per square metre while for some Ni/Cd batteries 1 per square metre may be acceptable. 

Clearly, the current collector must be stable to chemical attack by both electrolyte and active material and this limits the choice of material, e.g. lead is the only widely used material in a lead/acid battery. Corrosion of the collector and shedding of the active paste are the two major causes of battery failure. 

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Uses. The largest use of lithium metal is in the production of organometaUic alkyl and aryl lithium compounds by reactions of lithium dispersions with the corresponding organohaHdes. Lithium metal is also used in organic syntheses for preparations of alkoxides and organosilanes, as weU as for reductions. Other uses for the metal include fabricated lithium battery components and manufacture of lithium alloys. It is also used for production of lithium hydride and lithium nitride. 

Recycling of the major valuable battery components is an important factor influencing the introduction into the market and the economic development of the system. Figure 10 shows a breakdown of the materials and components, their weight fractions and recyclability. 

In many countries starter batteries are almost 100 percent recycled PVC separators can cause some problems here [67]. A prior separation of PVC from other battery components, which is quite tedious, would be desirable, because a PVC content decreases the recycling purity of the container polypropylene and makes further processing of this plastic more difficult. Also, any chlorine compounds liberated can form environmentally hazardous products with other substances the usual remedy is to install costly filter stations, with the residues representing possibly toxic wastes requiring special disposal methods. 

A. Jena and K. Gupta. An innovative technique for pore structure analysis of fuel cell and battery components using flow porometry. Journal of Power Sources 96 (2001) 214-219. 

There is not too much information available on the battery separator market in the literature. It is estimated that about 30% of the rechargeable lithium battery market or 1.5 billion is the size of the battery materials or components market. Battery separators for lithium batteries are about a 330 million market within the total battery components market. ° Recently, the Freedonia Group has reported that the U.S. demand for battery separators will increase to 410 million in 2007 from 237 million in 1977 and 300 million in 2002, respectively. ... 

Uses. Manufacture of dry cell batteries component of fluxes in zinc and tin plating fume is evolved in galvanizing operations mordant in dyeing and printing fertilizer hardener for formaldehyde-based adhesives... 

Secondary battery components containing pherdazl, (V), and triazine, (VI), free radicals were prepared by Nakahara et al. (3). 

At the present time, a large number of spent batteries are disposed of directly into the urban waste stream without proper controls. In addition to the most common systems such as zinc-carbon, alkaline manganese and nickel-cadmium, these now include, at an increasing rate, nickel-metal hydride and lithium cells. Such disposal is of serious concern because of the possible effects of battery components on the environment. Consequently, most countries are now evolving policies for collection and recycling. The majority of lead-acid batteries are recycled, but the number of recycling plants in operation worldwide for other battery systems is still very small due to the unfavourable economic balance of such operations (see Table A3.1). Some of the procedures for the disposal and recycling of battery materials are now briefly described. 

Ren, S. and Frymier, P.D. (2003) Use of multidimensional scaling in the selection of wastewater toxicity test battery components, Water Research 37 (7), 1655-1661. 

High-energy density batteries having superior stability were prepared Morioka [1] using polynitroxyl radicals components, (I). Sulfur, (II), and boron, (III), free radical analogues prepared by Bannai [2] were also effective as secondary battery components. 

The effective specific energy of various batteries amounts presently to some 10-25% of theoretical specific energy (defined as the reversible work of the cell reaction per unit weight of reactive electrode materials). The extent of departure from the theoretical value depends on (1) the weight of nonactive battery components ... 

The safety considerations involve primarily the consequences of the high temperature of the system. No significant reactions of the battery components with air have been observed under conditions of rupture of cells at the operating temperature. A massive short circuit in a 20-kWh module which resulted in generation of 20 kWh of heat did not present any hazard, except for a 100 C increase of the temperature of the vessel. 

Table 2. Relative Health Impact of Major Battery Components...

J.P. Guptil, Disposal of Lithium Batteries and the Potential for Recycling of Lithium Battery Components, presented at the 5th International Seminar on Battery Waste Management, Deerfield Beach, FL, November 1993. 

A different situation exists during battery manufacturing and during battery disposal/recycling operations where workers may come into direct contact with toxic or harmful battery components. In addition, members of a community may be unknowingly exposed to toxic battery materials due to the improper disposal of battery wastes and the injection of toxic battery materials into their ecosystems. The latter may affect both man, animal, and plant life adversely. In general, the toxic effect of a particular material depends upon the nature of the exposure and its concentration whether it be by contact, ingestion, inhalation, or a combination of these. 

Lithium has a number of advantages over other materials for battery manufacture. It is the lightest tme metal, and it also has a high electrochemical reduction potential, that is, it occurs at the bottom of Table 9.1. There is one disadvantage in using lithium in that it is very reactive, a feature that poses problems not only in manufacture but also in the selection of the other battery components. Despite this, there are a large number of lithium-based primary cells available, both in traditional cylindrical form and as button and flat coin cells. 

But before that, let us see what are the battery industry s requirements for the purity of lead used in the manufacture of battery components. 

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