The 'Shocking' Story of the Battery
- 2010 10 Mar
What do automobiles, computers, flashlights, and radios all have in common? If you think about it, you'll realize that each one of these things has a battery somewhere inside it. Batteries are devices that store electricity so that we can use it when we want to. Some types of batteries are designed to be used once. When they go "dead," we throw them away. Others are able to be "recharged" and used over and over. As it turns out, it took a long time for people to figure out enough about electricity to be able to invent the battery. It was a fascinating journey that led to an invention that changed the world.
The World Before the Battery
Most people in the United States have heard that Benjamin Franklin discovered electricity one day while flying a kite in a thunderstorm. The truth of the matter is that it was not Benjamin Franklin. No one knows exactly who discovered electricity, but the earliest mention of it is from an observation made by a Greek philosopher named Thales about 600 B.C. Thales noticed that when he rubbed a piece of amber with a wool cloth, small bits of straw seemed to jump and stick to the amber. Although he did not know exactly what was happening, he had discovered static electricity.
Thales' experiment was repeated many times over a period of centuries, but nothing useful ever came from it. Scientists were naturally curious, but they never devised any experiments to investigate this strange phenomenon further. In the mid-1700s, an English physicist named John Canton invented a device called a pith ball electroscope. The device held two small balls by silk threads. When he rubbed a piece of glass with a cloth and moved it toward the ends of the silk threads, the two pith balls moved apart. This was the start of understanding electricity. Something was causing the pith balls to repel one another, but what?
Also in the mid-1700s, a Dutch scientist named Pieter van Musschenbroek invented a device at the University of Leyden which became known as a "Leyden Jar." It was a glass jar that could store electricity! Actually, it was a very special glass jar. The inside was coated with a metal foil. The outside had a second metal foil wrapped around it. By rubbing a piece of glass with cloth, van Musschenbroek could continue to add static electrical charge to this special jar.
What van Mussechenbroek had really invented is an electrical component called a "capacitor." Now scientists could at least store electricity for use in experiments. The problem was, this was static electricity. When someone went to use it, the electricity would "spark" and quickly go away. Have you ever given someone an electrical shock when you touched them? You were storing static electricity in your body. In a way, you were a Leyden Jar! In order for scientists to better understand electricity, they needed a way to store it and control it for their own uses.
Italian scientists made some observations that would help accomplish this task. Believe it or not, the invention of the battery began with an observation made in the late 1700s by Luigi Galvani, a professor of anatomy at Bologna University in Italy. Galvani was studying frogs to try to learn how nerves make muscles move. In order to do this, he had to dissect frogs. One day, when he had freshly killed a frog, a nearby lightning strike caused the frog's leg to move violently. Later, Galvani observed that when he hung a frog's leg on a brass hook, and the hook touched a different kind of metal, the frog's leg would twitch. His conclusion was that he had discovered "animal electricity."
In 1800 at the University of Pavia, also in Italy, a physics professor named Alessandro Volta heard about Galvani's discovery. After studying what Galvani had done, Volta concluded that the electricity was not in the frog, but in the metals. He created a unique experiment to prove this. Volta took some silver disks, some zinc disks, and some pieces of cloth that he had soaked in salt water. He built a stack with a silver disk, a piece of wet cloth, a zinc disk, and another piece of wet cloth. He repeated the sequence to make what was called a "Voltaic Pile." This voltaic pile created a chemical reaction that caused electricity to flow. Volta had built the first battery!
What Volta had done was really very important. People could now manufacture devices to create electricity for experiments. Up until this point, storing static electricity inside a Leyden Jar was the only way to save electricity for use in experiments.
The World of the Battery
Volta had cracked the secret code of batteries: chemical relationships could be used to create electricity. A flurry of battery research activity ensued in the 1800s. Innovation in the field of batteries began to spread across the world. Many different kinds of batteries were developed during this period. A few of the more noteworthy ones are described below.
In 1836, the British chemist and meteorologist John Daniel invented the "Daniel Cell," using copper sulfate and zinc sulfate. The materials that Daniel used were somewhat safer than those used by Volta. The Daniel Cell was able to supply about 1.1 volts of electricity.
In 1859, the French physicist Gaston Plante invented the first practical lead-acid battery that could be recharged. Plante's battery consisted of two spiral rolls of lead sheeting, separated by a linen cloth and immersed in a solution of sulfuric acid. Lead-acid batteries like Plante's are used in automobiles today.
In 1866, Georges Leclanche invented the carbon-zinc wet cell, and by 1868, over 20,000 of his wet cells were being used with telegraph equipment. This is a perfect example of how the battery helped change the world. It was an important device for use with telegraphs, which opened the doors to modern communications systems.
In 1881, Carl Gassner invented the first commercial zinc-carbon dry cell battery. Instead of using a liquid in the battery, Gassner made a paste from ammonium chloride and Plaster of Paris.
Waldmar Junger, a Swedish scientist, invented the first nickel-cadmium rechargeable battery in 1899. His first batteries were very good, much better in fact than the lead-acid batteries, but they were very expensive at the time they were invented. You may have seen these types of batteries at the store. They are commonly referred to as "NiCad" batteries.
In 1901, Thomas Edison invented the first alkaline battery. Inventors kept working on Edison's invention and began to shrink the battery down in size. You have probably used these kinds of batteries in some of your portable electronics. They often are called "AA" or "AAA" batteries.
The World After the Battery
Many people believe that the Bible is just an old book made up of fictional stories that have no role in our lives today. Nothing could be further from the truth! People who lived several thousand years ago had the same sin nature as people do today. The Bible is as relevant today as when it was originally written.
The reason for bringing this up is that we purposely left off one kind of battery that was invented in the 1800s. Why? Because it's old, outdated information that couldn't possibly affect us today. Or could it? Let's see.
In 1842, a Welsh physical scientist named William Robert Grove invented a device he called a "gas voltaic battery." Grove's invention was able to produce electricity by combining hydrogen and oxygen. Many universities today have rediscovered the principles behind Grove's work. You may have heard of these devices in the news. They are called "fuel cells," and there are many millions of dollars being used to support fuel cell research. Fuel cells hold the potential of providing low-cost, clean energy in the future. Imagine if Grove's work was treated like many treat the Bible! It would have been long forgotten.
The fuel cell is not really a battery. Batteries store their chemical reactants inside a closed case. That's why you can go to the store and buy batteries to use at home: they are encased. Fuel cells are not closed. They consume reactants to keep generating electricity. You have to keep adding materials to keep the reaction running.
Each day when I go to work, I drive by a facility called the Center for Hydrogen Research. They are doing some of the most advanced work in fuel cell technology. The automobile manufacturer, Toyota, has just set up a laboratory there to work on the next generation of fuel cell powered cars. One local manufacturing plant has already started using fuel cell powered lift trucks inside their factory. You will see many new inventions in this area in the near future.
Make Your Own Voltaic Pile
This is simple and pretty neat. You can recreate Volta's experiment using some pennies, some nickels, some paper towels (cut into penny-sized squares), and some salt water. If you have access to an instrument called a voltmeter, you can use it. If not, you could try to find a flashlight bulb with two wires on it.
Lay a nickel on a dish. Wet a piece of the paper towel in salt water, and place it on top of the nickel. Now lay a penny on top on the wet towel, and place another piece of paper towel soaked in salt water on top of it. Repeat the process, creating a stack containing three nickels and three pennies. It's kind of like a layer cake. When I did this, I used a voltmeter to measure the voltage between the bottom nickel and the top penny. I was able to produce nearly five volts using my voltaic pile!
Electrical resistance is measured in Ohms. The opposite of electrical resistance is electrical conductance. What is the unit of electrical conductance? It's the "Mho," which is "Ohm" spelled backwards!
*This article published March 10, 2010.
Ray and Gale Lawson have been homeschooling their three children since 1995. Ray holds a B.S. in Electrical Engineering from the Virginia Military Institute and works for Washington Safety Management Solutions, LLC. Gale holds a B.S. in Mechanical Engineering from the University of South Carolina and is a full-time mom and teacher. They are members of Breezy Hill Baptist Church in Graniteville, SC. Questions, comments, and suggestions are always welcomed and can be emailed to them at email@example.com (Ray) or firstname.lastname@example.org (Gale).
This article was originally published in the July/Aug 2008 issue of Home School Enrichment Magazine. For more information, and to request a FREE sample issue, visit http://HomeSchoolEnrichment.com