Nickel-cadmium battery electrolyte

Spontaneous low resistance internal short circuits can develop in silver—zinc and nickel—cadmium batteries. In high capacity cells heat generated by such short circuits can result in electrolyte boiling, cell case melting, and cell fires. Therefore cells that exhibit high resistance internal short circuits should not continue to be used. Excessive overcharge that can lead to dry out and short circuits should be avoided. 

The nickel-cadmium battery was invented by Jungner in 1899. The battery used nickel hydroxide for the positive electrode, cadmium hydroxide for the negative electrode, and an alkaline solution for the electrolyte. Jungner s nickel-cadmium battery has undergone various forms of the development using improved materials and manufacturing processes to achieve a superior level of performance. 

Jahn-Teller distortions 309 ff Japanese separators 264, 267 Joule effect, heat losses 13 jump frequency, solid electrolytes 532 Jungner nickel cadmium batteries 22... 

In 1899, the nickel-cadmium battery, the first alkaline battery, was invented by a Swedish scientist named Waldmar Jungner. The special feature of this battery was its potential to be recharged. In construction, nickel and cadmium electrodes in a potassium hydroxide solution, it was the first battery to use an alkaline electrolyte. This battery was commercialized in Sweden in 1910 and reached the Unites States in 1946. The first models were robust and had significantly better energy density than lead-acid batteries, but nevertheless, their wide use was limited because of the high costs. 

Subcategory A encompasses the manufacture of all batteries in which cadmium is the reactive anode material. Cadmium anode batteries currently manufactured are based on nickel-cadmium, silver-cadmium, and mercury-cadmium couples (Table 32.1). The manufacture of cadmium anode batteries uses various raw materials, which comprises cadmium or cadmium salts (mainly nitrates and oxides) to produce cell cathodes nickel powder and either nickel or nickel-plated steel screen to make the electrode support structures nylon and polypropylene, for use in manufacturing the cell separators and either sodium or potassium hydroxide, for use as process chemicals and as the cell electrolyte. Cobalt salts may be added to some electrodes. Batteries of this subcategory are predominantly rechargeable and find application in calculators, cell phones, laptops, and other portable electronic devices, in addition to a variety of industrial applications.1-4 A typical example is the nickel-cadmium battery described below. 

Lead hydroxide is used in making porous glass in electrical-insulating paper in electrolytes in sealed nickel-cadmium batteries in recovery of uranium from seawater and as a catalyst for oxidation of cyclododecanol. 

When is a nickel cadmium battery an electrolytic cell ... 

Rote et al. (1993, 1994) used a carotid thrombosis model in dogs. A calibrated electromagnetic flow meter was placed on each common carotid artery proximal to both the point of insertion of an intravascular electrode and a mechanical constrictor. The external constrictor was adjusted with a screw until the pulsatile flow pattern decreased by 25 % without altering the mean blood flow. Electrolytic injury to the intimal surface was accomplished with the use of an intravascular electrode composed of a Teflon-insulated silver-coated copper wire connected to the positive pole of a 9-V nickel-cadmium battery in series with a 250000 ohm variable resistor. The cathode was connected to a subcutaneous site. Injury was initiated in the right carotid artery by application of a 150 xA continuous pulse anodal direct current to the intimal surface of the vessel for a maximum duration of 3 h or for 30 min beyond the time of complete vessel occlusion as determined by the blood flow recording. Upon completion of the study on the right carotid, the procedure for induction of vessel wall injury was repeated on the left carotid artery after administration of the test drug. 

Flooded battery — A battery (or a cell) containing an excess of electrolytic solution (in contrast to starved electrolyte batteries). Usually relevant to rechargeable -> lead-acid and -> nickel-cadmium batteries. Flooded battery design is typically applicable for heavy duty batteries, equipped with a vent valve that releases pressure buildup due to gas evolution. The excess electrolyte affects more sturdy batteries to become less susceptible to damage due to overcharge. In addition, the thermal conductivity of the electrolyte affords more efficient heat dissipation and thus higher -> power densities. 

Starved electrolyte battery — A -> battery with minimum amount of -> electrolyte. The electrolyte in starved electrolyte cells or batteries exists in the porous structure of the - electrodes and absorbed in the separator, so it contains little or no free fluid electrolytic solution. This type of batteries is used in certain constructions of sealed - lead-acid and -> nickel-cadmium batteries that rely on gas diffusion and recombination on the electrodes during charging or overcharging in order to maintain maintenance-free conditions, and to suppress pressure buildup. Starved electrolyte batteries benefit from larger - energy density due to the reduced amount of electrolyte. This design may suffer from poor heat dissipation compared with -> flooded batteries, thus for high power applications this point has to be taken into account. 

A metal hydride battery similar to the nickel-cadmium battery has been developed by Sharp corporation. The battery is shaped in the form of a button of 20 mm diameter and can give 1.2 V. The anode in the battery is made of La-Ni-Sn alloy hydride, and the cathode is nickel oxide. Potassium hydroxide solution in polyamide-resin is the electrolyte. The battery exhibits high energy density (i.e.) 1.5 to 2.0 times that of the Ni-Cd battery, good cycling life and superior low temperature behaviours. 

In 1899, Waldmar Jungner (Sweden) invented the nickel-cadmium battery (Ni/Cd) [6]. The battery used nickel for the cathode, cadmium for the anode, and an aqueous solution of potassium hydroxide for the electrolyte. The applications of these batteries were limited because of the high cost of the materials compared to other battery systems (lead acid). In 1901, Edison (USA) modified the design of the battery by replacing the anode material with iron [7]. This design is known as the... 

Nickel-cadmium batteries use a hydrate nickel oxide as positive electrode, a metallic cadmium as negative electrode and an aqueous solution of potassium hydroxide as electrolyte [17]. The production of electrons at the negative plate during discharge occurs via the following semi-reaction ... 

With hydrometallurgical processes, the presence of NiCd or NiMH batteries requires an additional stage in order to isolate the cadmimn, in nickel-cadmium batteries, and the nickel found in certain batteries at a content of less than 0.1% and in the form of nickel steel or an electrolytic nickel coating. 

The negative electrodes in nickel-cadmium batteries are made up of finely distributed cadmium. The positive electrodes are composed of Ni(III) oxide hydroxide (with graphite or Ni powder added to enhance the conductivity). The electrolyte is usually a 20 % potassium hydroxide solution. 

The cell potential has an average value of 1.25 V. Although the overall reaction does not apparently involve the electrolyte, the KOH does in fact participate in each of the half-cell reactions. Although the Edison battery is designed and suitable for regular cyclic service, the efficiency of charge is only 60% thus, it has now been almost completely replaced by the more efficient (72%) nickel-cadmium battery, which is itself inferior in energy efficiency to the lead-acid battery with an efficiency of about 80%. 

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