Battery Nicad

In a nickel-cadmium battery (Nicad), cadmium is oxidized to Cd(OH)2 at the anode, while Ni203 is reduced to Ni(OH)2 at the cathode. A portable CD player uses 0.175 amp of current. How many grams of Cd and Ni203 are consumed when the CD player is used for an hour and a half ... 

Another problem encountered by manufacturers and users of NiCads batteries is the breakdown, by electrolysis, of water. This ought to be prevented otherwise the cells may explode. As with lead-acid batteries, NiCads are also prone to electrolysis-mediated breaking down of water in the electrolyte into potentially explosive hydrogen and oxygen. Battery manufacturers take great steps... 

Much of the cadmium produced worldwide is used in nickel-cadmium (nicad or Ni-Cd) batteries. Nicad batteries can be used over and over. When a nicad battery has lost some or all of its power, it is inserted into a unit that plugs into an electrical oudet. Electricity from the oudet recharges the battery. 

One of cadmiums primary uses is in the manufacture of batteries. Nickel-cadmium batteries, also known as nicad batteries, can be recharged many times with only small losses of efficiency. This makes nicad batteries more durable and longer lasting than rechargeable lead batteries. Nicad batteries are also more convenient... 

Nickel-metal hydride is a popular alternative to Nicad batteries since they are capable of operating 75 percent longer after each charge, are less likely to suffer memoiy effects, and pose less of an environmental disposal problem. The difference between nickel-metal and Nicad batteries is that the negative... 

Lithium-Ion Cells. Lithium-ion cells and the newer alternative, lithium-ion-polymer, can usually run much longer on a charge than comparable-size Nicad and nickel-metal hydride batteries. Usually is the keyword here since it depends on the battery s application. If the product using the battery requires low levels of sustained current, the lithium battery will perform very well however, for high-power technology, lithium cells do not perform as well as Nicad or nickel-metal hydride batteries. 

After use, a nickel-cadmium (Nicad) battery has 0.129 g of Cd(OH)2 deposited on the anode. The battery is inserted into a recharger, which supplies 0.175 A. How many hours does the Nicad battery need for recharging so that all the Cd(OH)2 is converted back to Cd Assume that the recharger is 100% efficient. (See Problem 76 for a description of the Nicad 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)... 

Nickel, Ni, is also used in alloys. It is a hard, silver-white metal used mainly for the production of stainless steel and for alloying with copper to produce cupronickels, the alloys used for nickel coins (which are about 25% Ni and 75% Cu). Nickel is also used in nicad batteries and as a catalyst, especially for the addition of hydrogen to organic compounds, as in the hydrogenation of vegetable oils (Section 18.6). 

Flaving had over 150 years of technical development behind them, lead-acid batteries can be custom-tailored to specific applications, such as those requiring deep discharge cycles (e.g., where the batteries are used as the sole power source for electrical equipment) and for battery backup uses such as in large uninterruptible power supply systems in data centers. Moreover, lead-acid cells not only have low internal resistance but also experience no memory effect as do some more exotic cell designs, such as NiCads. This enables these cells to produce enormous currents and have a moderately long, predictable life.1... 

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). 

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. 

Like many technological innovations, nickel-cadmium batteries carry risks as well as benefits. After being discharged repeatedly, they eventually wear out. In theory, worn-out nicad batteries should be recycled. In practice, however, many end up in garbage dumps. Over time, discarded nicad batteries release toxic cadmium. The toxicity of this substance makes it hazardous to the environment, as cadmium can enter the food chain. Long-term exposure to low levels of cadmium can have serious medical effects on humans, such as high blood pressure and heart disease. 

Write the two half-reactions and the overall cell reaction for the process that occurs when a nicad battery is being recharged. 

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. 

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. 

Cadmium is close to lead and mercury as a metal of current toxicological concern.12346 Extraction of lead and zinc ores, which contain cadmium, pollutes the environment with cadmium. The use of cadmium before 1900 was infrequent however, its valuable metallurgical properties, such as resistance to corrosion, increased its use markedly, for example in the manufacture of alloys and as a coating on steel. It is also now widely used in nickel cadmium ( nicad ) batteries. Coal and other fossil fuels contain cadmium which is released into the environment on combustion. 

What kind of system (open, closed, or isolated) is each of the following cells (a) dry cell (b) fuel cell (c) nicad battery ... 

Since portable computers have unique characteristics as a result of the portability, they have unique accessories as well. First of all, portable computers can use either of two power sources batteries or AC power. There are many different sizes and shapes of batteries, but most of them are either Nickel-Cadmium (NiCad), Lithium Ion, or Nickel Metal Hydride (NiMH). All of these perform equally well as batteries, but NiCad batteries can only be recharged a finite number of times. After a time, they develop a memory and must be recharged on a special deep charging machine. NiMH and Lithium Ion batteries don t normally develop a memory and can be recharged many times, but they re a little more expensive. 

Among the most important uses of cadmium in the United States is in the production of nicad (nickel-cadmium), or rechargeable, batteries. It is also used in pigments, coatings and plating, manufacture of plastic products, and alloys. An alloy is made by melting and mixing two or more metals. The mixture has properties different from those of the individual metals. 

Nicad batteries are used in a large variety of appliances, including compact disc players, cell phones, pocket recorders, handheld power tools, cordless telephones, laptop computers, camcorders, and scanner radios. A few automobile manufacturers have explored the possibility of using nicad batteries in electric cars. For example, the Mitsubishi Corporation of Japan built and marketed an experimental car called the Libro EV that operated on either traditional lead batteries or on nicad batteries. 

Nicad (nickel-cadmium) batteries can be recharged in a plug-in unit such as this one. IMAGE COPYRIGHT 2009, WETC. USED UNDER LICENSE FROM SHUTTERSTOCK.COM. 

Nickel is also very popular in the manufacture of batteries. Nickel-cadmium (nicad) and nickel-metal hydride (NiMH) batteries are the most popular of these batteries. They are used in a great variety of appliances and electronics, including hand-held power tools, compact disc (CD)... 

NiMH and nicad batteries are used in electronic devices including laptops and cell phones. lAAAGE COPYRIGHT 2009, ROZBYSHAKA. USED UNDER LICENSE FROM SHUTTtRSTOCK.COM. 

Cordless tools and phones often use rechargeable batteries, such as the NiCad type, for power. The battery pack in the phone is recharged when the handset is replaced on the base. In this case, the base is plugged into an electrical outlet, which supplies the power to drive the nonspon-taneous recharge reaction. 

Anaiyze and Conciude Zinc-carbon, alkaline, mercury, lithium, and NiCad batteries all contain a separator between the anode and cathode that allows exchange of ions but keeps the anode and cathode reactants from mixing. No such separator is present (or needed) in a lead-acid battery. 

---