This week’s question was asked by Dennis Newman, fifth frade, Camp Douglas Elementary School.
Teacher: Jan Schmidt.
QUESTION: Who made the first battery?
Primitive batteries were crafted by the Parthians in Baghdad around 250 BC. They took a clay jar and filled it with vinegar. A copper cylinder was placed inside the clay jar with an iron rod poking out the top. Their crude battery was used to electroplate silver.
The modern battery was invented by an Italian by the name of Alessandro Volta in 1800. You might guess that the unit of electrical pressure, the volt, is named after him. Volta made a pile or stack of zinc and copper plates with vinegar or salt brine, pieces of leather or heavy paper placed between each plate.
The plates were stacked in alternating form with one on top of the other. The bottom plate (zinc) was the negative terminal and the top plate (copper) was the positive terminal. Volta demonstrated and explained the principle of the “electric column” to Napoleon in 1801. Volta’s battery was the first device to provide a continuous current.
Lithium-ion batteries are all the rage these days. They can be found in laptops and cell phones. Pound for pound, lithium-ions pack a powerful punch. They are lightweight and rechargeable and six times more efficient than a lead-acid battery in a typical car or truck. They’ve been in the news this past year. A few have burst into flames. It’s only two or three per million batteries, but the possibility does produce a potential problem. If it happens on an airliner, for example, it’s really bad news.
Lithium-ions do have some drawbacks. If completely discharged, they’re ruined. They degrade rather quickly as soon as they leave the factory, whether they’re used or not. Lithium-ion batteries deteriorate rapidly when operating in a high temperature environment.
You may remember other rechargeable batteries that were around for many years. The Ni-Cad (nickel-cadmium) and NiMH (nickel-metal hydride) batteries were the first really good rechargeables. But they had a “memory effect.” If not completely discharged before recharging, you could never really get them back to their full charge. These batteries gradually lost their maximum energy capacity if they were repeatedly recharged after being only partially discharged. The battery appeared to “remember” the smaller capacity.
Li-Po (lithium polymer) batteries are cousins to the lithium-ion batteries. The electrolyte is a paste instead of liquid. Li-Po batteries are popular rechargeable batteries for computer tablets and radio-controlled planes and helicopters in which weight is a consideration.
Batteries consists of an anode, cathode and electrolyte. The zinc-carbon chemistry is common in many inexpensive AAA, AA, C and D dry cell batteries. The cathode (negative terminal or case) is zinc, the anode (positive terminal or button on top) is manganese dioxide, and the electrolyte is a paste of ammonium chloride or zinc chloride.
Alkaline batteries are also common in AA, C and D dry cell batteries. The anode is composed of a manganese dioxide mixture, while the cathode is a zinc powder.
The assigning of positive and negative can be confusing. Conventional flow is from positive to negative and used by electrical engineers. Electron flow, negative to positive, is most often seen in introductory textbooks, writings of scientists, and solid-state physicists.
Due to a chemical reaction within the battery, the cathode builds up an excess of electrons. This causes an electrical difference between the anode and the cathode. When the circuit is closed, with the help of a “conductive path” between the anode and cathode, the electrons travel to the anode. This, in turn provides power to any appliance placed along the way.
Alessandro Volta was a humble man and given many honors but preferred the domestic life of farm and family. He was knighted by Napoleon in 1810, was a professor of physics and chemistry in the northern Italian lake country around Como. He was revered by his students and consulted with scientists from all over Europe. He was the first to isolate methane and found it was explosive when mixed with air and subjected to an electric spark. It’s the basis of all internal combustion engines in cars and trucks.
At age 74, Volta retired to his country farm to spend time with his wife, Maria Teresa. They had raised three sons. He died in March, 1827, at age 82.
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