Nicad cells

A nicad cell has a cadmium electrode and another electrode that contains nickel(lll) oxyhydroxide, NiO(OH). When the cell is discharging, cadmium is the anode. When the cell is recharging, cadmium is the cathode. The electrolyte is a base, sodium hydroxide or potassium hydroxide. 

The design of alkaline nickel-cadmium (Ni/Cd, nicad ) cells varies ac-... 

Although more expensive, the nickel-cadmium cell is superior to the Leclanche cell in almost all respects, except that the toxicity of cadmium places some restrictions on the disposal of defunct nicad cells. Even the rechargeable Ni/Cd cell has a limited life, due to a memory effect after discharge (i.e., it is not quite fully rechargeable), and consideration must be given to proper disposal or, better, recycling. Peugeot s entry in the ZEV field, the Model 106 electric car, uses 20 liquid-cooled 6 V Ni/Cd cells to deliver 120 V, and the supplier undertakes to recycle the battery at the end of its useful life. 

Beryllium connections and contacts are employed for switchgear and relays. Beryllium oxide is used as substrata for electronic circuits. Cadmium is used in television and fluorescent light phosphors. Cadmium, nickel and mercury are employed in batteries such as "nicad" cells and mercury cells. Mercury is used in fluorescent lamps, electrical switches, and outdoor lamps, as well as instruments for measuring pressure, temperature, and density. Selenium is employed as a photoreceptor in copying machines, and as a semiconductor in rectifiers. Lead applications include lead add storage batteries, a component in color television glass, and, in its oxide form, use as a dielectric material. 

Nickel-Cadmium (NiCad) cells quickly become one of the most popular rechargeable bat-... 

The Lead Storage Battery 21-24 The Nickel-Cadmium (Nicad) Cell... 

The nickel-cadmium (nicad) cell has gained widespread popularity because it can be recharged. It thus has a much longer useful life than ordinary (Leclanche) dry cells. Nicad batteries are used in electronic wristwatches, calculators, and photographic equipment. 

The solid reaction product at each electrode adheres to the electrode surface. Hence, a nicad battery can be recharged by an external source of electricity that is, the electrode reactions can be reversed. Because no gases are produced by the reactions in a nicad battery, the unit can be sealed. The voltage of a nicad cell is about 1.4 volts, slightly less than that of a Leclanche cell. 

The positive electrode, the cathode, is similar to that in nicad cells and consists of a mixture of NiO(OH)/Ni(OH)3 and Ni(OH)2. An alloy that supports hydride formation replaces the cadmium as the negative anode. The alloy most commonly used is derived from LaNis, in which a mixture of other lanthanides replaces the lanthanum, and a nickel-rich alloy replaces the nickel, to give a general formula LnA/5. The anode is composed of an agglomeration of alloy powder. A small amount of potassium hydroxide is added as an electrolyte. The cell voltage is 1.3 V, making these cells suitable for the direct replacement of nicad batteries. The cell construction is identical to that of the nicad cell (Figure 9.10), with the cadmium replaced by metal hydride. The approximate cell reactions are as follows. 

The nickel—cadmium cell (nicad cell) is a conunou storage battery. It is a voltaic cell consisting of an anode of cadmium and a cathode of hydrated nickel oxide (approximately NiOOH) on nickel the electrolyte is potassium hydroxide. Nicad batteries are used in calculators, portable power tools, shavers, and toothbrushes. The half-cell reactions during discharge are... 

Nickel(lll) compounds are used in batteries. For example, in the nickel-cadmium (Nicad) cell, the cathode half-reaction is NiO(OH) + H +... 

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