Batteries button battery

All flashlight batteries, button batteries, compact rechargeable batteries and vehicle storage batteries operate under the same basic principles. An electrochemical cell is constructed of two chemicals with different electron-attracting capabilities. Called an electrochemical couple, these two chemicals, itntncrscd in an electrolyte (material that carries the flow of energy between electrodes), are connected to each other through an external circuit. 

A button battery is much smaller than an alkaline battery. Button batteries are commonly used in watches, as shown in Figure 11.9. Because of its small size, the button battery is also used for hearing aids, pacemakers, and some calculators and cameras. The development of smaller batteries has had an enormous impact on portable devices, as shown in Figure 11.10. 

An increasing number of household batteries are being used today. On average, a person owns about two button batteries, 10 normal (A, AA, AAA, C, D, 9V, etc.) batteries, and throws out about eight household batteries per year. About 3 billion batteries are sold annually in the United States averaging about 32 per family or 10 per person.5 9 Table 29.1 indicates the typical types of household batteries. 

There are two major types of household batteries (a) Primary batteries are those that cannot be reused. They include alkaline/manganese, carbon-zinc, mercuric oxide, zinc-air, silver oxide, and other types of button batteries, (b) Secondary batteries are those that can be reused secondary batteries (rechargeable) include lead-acid, nickel-cadmium, and potentially nickel-hydrogen. 

Mercuric oxide batteries are being gradually replaced by new technologies such as silver oxide and zinc-air button batteries that contain less mercury. 

Mercury oxide and silver oxide button batteries are sometimes collected by jewelers, pharmacies, hospitals, and electronic or hearing aid stores for shipping them to companies that reclaim mercury or silver. Some batteries cannot be recycled. If recycling is not possible, batteries should be saved for disposing of at a hazardous waste collection. Battery recycling and button battery collection may be good options at present, but may change as the mercury concentration in the majority of button batteries continues to decrease. 

Two common types of button batteries both use a zinc container, which acts as the anode, and an inert stainless steel cathode, as shown in Figure 11.11 on the next page. In the mercury button battery, the alkaline electrolyte paste contains mercury(II) oxide, HgO. In the silver button battery, the electrolyte paste contains silver oxide, Ag20. The batteries have similar voltages about 1.3 V for the mercury cell, and about 1.6 V for the silver cell. 

The reaction products in a mercury button battery are solid zinc oxide and liquid mercury. The two half-reactions and the overall equation are as follows. 

A common type of button battery, shown here, contains silver oxide or mercury(ll) oxide. Mercury is cheaper than silver, but discarded mercury batteries release toxic mercury metal into the environment. 

A five-year-old boy swallowed a button battery containing lithium (546). During the 4 days after ingestion, he developed a serum lithium concentration of 0.71 mmol/l without signs of lithium toxicity and with normal renal function. The battery was eventually retrieved by gastrotomy. 

The authors warned that button battery ingestion can be a source of lithium poisoning in youngsters. 

Mahon PT, White JS, Thompson RLE. Systemic absorption of hthium following ingestion of a hthium button battery. Hum Exp Toxicol 2004 23 192-5. 

Litovitz T (2001) Button batteries. In Ford MD, Delaney KA, Ling LJ, and Erickson T (eds.) Clinical Toxicology, pp. 1027-1031. Philadelphia Saunders. 

Litovitz T and Schmitz BE (1992) Ingestion of cylindrical and button batteries An analysis of 2,382 cases. Pediatrics 89 747-757. 

The discharge mode of Ni-Cd batteries is dependent on their applications. The most common one is the constant-current discharge, in which the current can be changed from very low (e.g., in the case of button-batteries) to very large (e.g., for batteries for wireless tools). There are also other discharge modes, such as constant-resistance discharge, content-power discharge, etc. 

From a preliminary screening of importation data from the governmental central statistics office, it was observed that mercury was imported as mercury quicksilver and mercury colloidal suspension. Imported goods that contained mercury were mercury vapour lamps, TV camera tubes, clinical thennometers, batteries (button cell), fluorescent lamps and electrical switches. Mercury could also be present in coal that is imported to be used for power generation and other consumer products (e.g. bleaching creams). 

A primary battery cannot be recharged, so it is discarded when the components have reached their equilibrium concentrations, that is, when the cell is dead. We ll discuss the alkaline battery and the mercury and silver button batteries. 

Mercury and Silver (Button) Batteries Mercury and silver batteries are quite similar. Both use a zinc container as the anode (reducing agent) in a basic medium. The mercury battery employs HgO as the oxidizing agent, the silver uses Ag20, and both use a steel can around the cathode. The solid reactants are compacted with KOH and separated with moist paper. The half-reactions are... 

A silver button battery used in a watch contains 16.0 g of zinc and can run until 80% of the zinc is consumed, (a) How many days can the battery run at a cunent of 4.8 milliamps (b) When the battery dies, 95% of the Ag20 has been consumed. How many grams of Ag was used to make the battery (c) If Ag costs 5.50 per troy ounce (31.10 g), what is the cost of the Ag consumed each day the watch runs ... 

Member States shall prohibit the marketing of all button batteries and accumulators containing more than 2% of mercury by weight as well as the appliances into which they are incorporated. 

As regards batteries and accumulators as well as button batteries and accumulators containing cadmium or mercury above the levels indicated in Article 4.1 and 4.3 or lead above 0,1% of the weight of the battery, the chemical symbol for the metal concerned, Cd, Hg, Pb, shall be indicated. The symbol indicating the heavy metal content shall be printed beneath the symbol referred to in paragraph 1 of this Annex. 

Figure 20.9 Alkaline batteries are more efficient than zinc-carbon dry cells and are useful when smaller batteries are needed. Silver button batteries are even smaller, making them well suited to devices such as watches. 

Button batteries are small disk-shaped batteries used in watches, calculators, and cameras. They contain caustic metal salts such as mercuric chloride that may cause corrosive injury. 

D. Button batteries cause injury by corrosive effects resulting from leakage of the corrosive metal salts, by direct impaction of the disk-shaped foreign body, and possibly by local discharge of electrical current at the site of impaction. 

E. Button batteries usually cause serious injury only if they become impacted in the esophagus, leading to perforation into the aorta or mediastinum. Most cases involve large (25-mm diameter) batteries. If button batteries reach the stomach without impaction in the esophagus, they nearly always pass uneventfully via the stools within several days. 

B. X-rays of the chest and abdomen will usually reveal impacted button batteries. X-rays may also demonstrate air in the mediastinum from esophageal perforation or free abdominal air from gastric perforation. 

C. Specific ieveis. See specific chemical. Urine mercury levels have been reported to be elevated after button battery ingestion. 

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