Ni-Cd cell

From these data, the hydride cells contain approximately 30—50% more capacity than the Ni—Cd cells. The hydride cells exliibit somewhat lower high rate capabiUty and higher rates of self-discharge than nickel—cadmium cells. Life is reported to be 200—500 cycles. Though not yet in full production it has been estimated that these cells should be at a cost parity to nickel—cadmium cells on an energy basis. 

It has been known for some time that lithium can be intercalated between the carbon layers in graphite by chemical reaction at a high temperature. Mori et al. (1989) have reported that lithium can be electrochemically intercalated into carbon formed by thermal decomposition to form LiCg. Sony has used the carbon from the thermal decomposition of polymers such as furfuryl alcohol resin. In Fig. 11.23, the discharge curve for a cylindrical cell with the dimensions (f) 20 mm x 50 mm is shown, where the current is 0.2 A. The energy density for a cutoff voltage of 3.7 V is 219 W h 1 which is about two times higher than that of Ni-Cd cells. The capacity loss with cycle number is only 30% after 1200 cycles. This is not a lithium battery in the spirit of those described in Section 11.2. 

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. 

Sintered nickel electrodes used in nickel iron cells are usually thicker than those used in Ni-Cd cells. These result in high energy density cells, because very high discharge rates are usually not required. 

Ni-Cd cells — The nickel-cadmium cell is a secondary - battery that has a nominal cell potential of 1.20-1.25 V. The negative electrode comprises nickel hydroxide-nickel oxyhydroxide, the positive electrode is cadmium, and the electrolyte solution is based on aqueous potassium hydroxide (KOH, 32% in water). At the anode, the discharge reaction is the oxidation of cadmium metal to cadmium hydroxide with the release of two electrons [i] ... 

A typical Ni-Cd cell construction is presented in the Figure below [ii]. A cylindrical nickel-plated steel case... 

Ni-Cd cell — Figure, nickel-cadmium cell construction... 

Nickel-cadmium cell Ni-Cd cell Nickel-iron rechargeable cell -> Edison cell Nickel-metal hydride cell - Ni-MFlcell Nicotinamide adenine dinucleotide - NADH Nigraniline - poly aniline... 

Refuse to which PCB and dry cells and Ni-Cd cells had been added was tested. It was not possible, however, to observe the behavior of PCB and heavy metals since their concentrations in the slag did not show any marked difference. This may have been due to addition of cells that had each been cut into three pieces, thereby causing spotty distribution of the heavy metals. 

The Ni-Cd cell consists of four base elements, that is, cathode, anode, separator, and electrolyte. Nickel... 

Ni-Cd cells can be categorized into two major groups of batteries, vented and sealed, based on the cell construction. 

Early in 2000, CollectNiCad has issued the first data related to the number of Ni-Cd cells introduced into the european market according to market segments by applications (CollectNiCad 2000). The data compiled by CollectNiCad are presented in Figure 3. It has been calculated that approximately 340 million cells are sold effectively in Europe for an equivalent weight of 13,000 Tonnes. These cells are sold mainly assembled m power packs varying from 20 to 500 grams or more. 

Economic relationships among Ni-Cd cell manufacturers, battery manufacturers, manufacturers of Ni-Cd-powered products, and distribution channels are complex and varied. As a result, effective collection... 

Table 10 shows a comparison of RAM cell performance with other commercially available dry cells [56]. RAM cells have an excellent shelf life comparable with PAM cells and a good cycle life depending on depth of discharge (50-500 cycles), nearly in the range of Ni-Cd cells. The average discharge capacity even exceeds the values for Ni-Cd cells, only PAM cells are better. But one of the most important advantage of RAM cells is the low toxicity (0.025 % Hg... 

Figure 40. Cells disposed created by PAM, RAM (containing 0.025 % mercury per cell weight) and Ni-Cd cells in a Nintendo Gameboy application.

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