The Nickel-Cadmium Nicad Cell

The nickel-cadmium (nicad) cell had widespread popularity from 1950 until recently because it can be recharged. It thus has a much longer useful life than ordinary (Leclanche) dry cells. Nicad batteries have been used in electronic toys, camcorders, and photographic equipment. 

When the battery is delivering power the anode is cadmium, and the cathode is nickel(TV) oxide. The electrolytic solution is basic. The discharge reactions that occur in a nicad battery are 

---

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

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

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

The nickel-cadmium (nicad) battery, a rechargeable "dry cell" used in battery-operated devices, uses the following redox reaction to generate electricity ... 

The ubiquity of power electronic products such as laptops, cell phones, and digital cameras, as well as the growth in popularity of hybrid electric vehicles, drive the need for efficient, long-lasting, rechargeable batteries. The most common types include the nickel-cadmium (NiCad) battery, the nickel-metal hydride (NiMH) battery, and the lithium ion battery. 

Although one of the most common storage batteries is called the nickel/cadmium system ( NiCad ), correctly written (-)Cd/KOH/NiO(OH)(+), cadmium is not usually applied as a metal to form a battery anode. The same can be said with regard to the silver/cadmium [(-) Cd / KOH / AgO (+)] and the MerCad battery [(-)Cd/KOH/HgO(+)]. The metallic negative in these cases may be formed starting with cadmium hydroxide, incorporated in the pore system of a sintered nickel plate or pressed upon a nickel-plated steel current collector (pocket plates), which is subsequently converted to cadmium metal by electrochemical reduction inside the cell (type AB2C2). This operation is done by the customers when they start the application of these (storage)... 

Many types of rechargeable batteries are much more portable than a car battery. For example, there is now a rechargeable version of the alkaline battery. Another example, shown in Figure 11.20, is the rechargeable nickel-cadmium (nicad) battery. Figure 11.21 shows a nickel-cadmium cell, which has a potential of about 1.4 V. A typical nicad battery contains three cells in series to produce a suitable voltage for electronic devices. When the cells in a nicad battery operate as galvanic cells, the half-reactions and the overall cell reaction are as follows. 

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. 

The nickel-cadmium cell (or nicad battery Fig. 17.8) is used in handheld electronic calculators and other cordless electric implements such as portable shavers. Its half-cell reactions during discharge are... 

However, concerns about the toxicity of cadmium have accelerated the replacement of these batteries by nickel-metal hydride batteries, described in Section 9.3.5. In nickel-cadmium (nicad) batteries, the anode is cadmium and the cathode is an unstable nickel oxyhydroxide, formed in the unusual conditions found in the cell, and written variously as Ni(OH)3 or NiO(OH). It is generally formed together with stable nickel hydroxide, Ni(OH)2. The electrolyte is NaOH or KOH. The anode and cathode are assembled in a roll separated by a cellulose separator containing the electrolyte. The cathode/separator/anode roll is contained in a nickel-plated stainless steel can (Figure 9.10). The cell voltage is 1.3 V but the working voltage is usually nearer to 1.2 V. The schematic cell reactions are as follows. 

Nickel-cadmium ("nicad") batteries are very common because, unlike ordinary dry cell batteries, they can be recharged an indefinite number of times. Write the half-reactions for the oxidation and reduction reactions that take place when a nicad battery operates. 

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-cadmium (Nicad) batteries have an anode of solid cadmiiun and a cathode of solid nickeloxy hydroxide, NiO(OH). Aqueous potassium hydroxide is often used as an electrolyte. The reaction taking place in the cell is... 

By contrast, secondary batteries may be reused after regenerating their original redox chemicals. This is achieved by passing a current through the battery in the opposite direction to that during normal battery usage. The most common examples of secondary batteries are the lead-acid cell (there is one inside most cars) and nickel-cadmium batteries (commonly called NiCad batteries). 

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. 

Cadmium, along with nickel, forms a nickel-cadmium alloy used to manufacture nicad batteries that are shaped the same as regular small dry-cell batteries. However, a major difference is that the nicads can be recharged numerous times whereas the common dry cells cannot. A minor difference between the two types of cells is that nicads produce 1.4 volts, and regular carbon-zinc-manganese dioxide dry-cell batteries produce 1.5 volts. 

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

E) Nickel-Cadmium (NiCd or "nicad") secondary (rechargeable) cell, invented by Jugner86 in 1899, uses nickel oxyhydroxide NiO(OH) and Cd metal as electrodes in the discharge mode the cell reaction is... 

Nickel-cadmium cell (nicad battery) A dry cell in which the anode is Cd, the cathode is Ni02, and the electrolyte is basic. 

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 nicad galvanic cell has cadmium anodes, hydrated nickel oxide cathodes, and KOH as the electrolyte. The electrodes are arranged In jelly-roll fashion. 

---