Реферат: The Chemistry Of Batteries Essay Research Paper

more sulfuric acid is formed. This secondary cell produces 2V, a number of

these cells are typically combined in series to make up 6 or 12V batteries.

Advances in technology have recently made it possible for lead batteries to

have useful lives of 50 to 70 years. Lead acid batteries are commonly used

in automobiles for starting, lighting, and ignition. Another very important

use is for uninterruptable power supply systems for computer and telephones

systems.

The lead acid battery is known to be the lowest costing of secondary

batteries. When it is used in a way where it is never fully discharged, like

starting an automobile, it can last for up to 20 years and for many recharging

cycles. It has a much shorter lifetime when it is used for other applications,

for example powering a golf cart, when it is greatly discharged. If the

battery is overcharged it will quickly wear out due to internal corrosion and

loss of water. During these times when environmental pollution is such a

problem, over 95 percent of lead acid batteries are recycled into new

batteries.

An improvement on the nickel iron battery that was developed by

inventor Thomas Edison in the 1900 s, is the nickel cadmium battery. The

nickle cadmium battery has a cadmium negative electrode, a potassium

hydroxide electrolyte, a nonwoven fabric separator, and a nickel positive

electrode. It produces 12V and endures many more full discharges cycles

than the lead acid battery ( up to 1000). It s a small cell that is commonly

used in portable tools like telephone, electric toothbrushes and shavers.

Interestingly enough it is also used in air planes where long life is truly

important.

An improvement of the nickle-cadmium cell is the nickel metal

hydride cell, the cadmium negative electrode is replaced with a complex

metal alloy that, absorbs hydrogen gas as it is charged and sends it to the

electrolyte as it discharges. This solves the problem of the hydrogen