Nickel-zinc storage batteries

The reason for this limited cycle life is the high solubility of the zinc electrode in alkaline electrolyte the zincate ions formed are deposited again during the subsequent charging in the form of dendrites, i.e., of fernlike crystals. They grow in the direction of the counterelectrode and finally cause shorts. 

A remedy could be achieved by a decrease in the zinc solubility in the electrolyte or by suppression of dendrite formation cadmium-, lead-, or bismuth oxide, 

Thus in this system, in addition to the usual requirements, the separator has the task of delaying penetration for as long as possible. A membrane would be regarded as perfect which lets hydroxyl ions pass, but not the larger zincate ions. This requirements is best met by regenerated cellulose ( cellophane ) [10,11], which in swollen condition shows such ion-selective properties but at the same time is also chemically very sensitive and allows only a limited number of cycles the protective effects of additional fleeces of polyamide or polypropylene have already been taken into account. 

A remedy could be achieved by a decrease in the zinc solubility in the electrolyte or by suppression of dendrite formation oxides of cadmium, lead, or bismuth, as well as calcium hydroxide or aluminum hydroxide, have been added to the zinc electrode or the electrolyte for this purpose, but not with long-lasting effectiveness. 

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In acidic electrolytes only lead, because it forms passive layers on the active surfaces, has proven sufficiently chemically stable to produce durable storage batteries. In contrast, in alkaline medium there are several substances basically suitable as electrode materials nickel hydroxide, silver oxide, and manganese dioxide as positive active materials may be combined with zinc, cadmium, iron, or metal hydrides. In each case potassium hydroxide is the electrolyte, at a concentration — depending on battery systems and application — in the range of 1.15 - 1,45 gem"3. Several elec-... 

Thus films can be divided into two groups according to their morphology. Discontinuous films are porous, have a low resistance and are formed at potentials close to the equilibrium potential of the corresponding electrode of the second kind. They often have substantial thickness (up to 1 mm). Films of this kind include halide films on copper, silver, lead and mercury, sulphate films on lead, iron and nickel oxide films on cadmium, zinc and magnesium, etc. Because of their low resistance and the reversible electrode reactions of their formation and dissolution, these films are often very important for electrode systems in storage batteries. 

Batteries vary in size and chemistry. Shown here are an automobile lead-storage battery, rechargeable nickel-cadmium cells, alkaline cells, and zinc-carbon dry cells. 

Barium sulfate Calcium plumbate Cobalt sulfate (ous) Lead Lead oxide, black Lead sulfate Lithium Nickel oxide (ic) batteries, storage/dry cell Zinc... 

An important aspect of lead is that it is a recoverable resource. It has been estimated that more than 95% of the batteries sold in the United States are ultimately recycled, and it takes considerably less energy to recycle lead, a low-melting metal (mp 327.4°C), than to produce the metals used in other storage battery systems (nickel, iron, zinc, silver, and cadmium) in battery-grade quality. 

The nickel-zinc battery does not impose any special handling or storage requirements beyond those of any other commercially available battery. However, it must be realized that any battery does impose some safety and handling issues such as electrical hazards or corrosive electrolyte spillage. A material safety data sheet (MSDS) and operating/handling instructions should be obtained from the battery manufacturer. 

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