Allessandro Volta was an Italian physicist and chemist who invented the first electric battery in 1799. He experimented with chemically generating electricity using dissimilar metals immersed in saltwater. He determined that zinc and copper produced the best results. He made a voltaic pile by stacking alternating zinc and copper discs with saltwater soaked cloth or cardboard between the discs.
Anyone can perform experiments similar to Volta’s using materials that can be found in many homes or purchased at a hardware, building supply or general merchandise store.
Single-cell Battery
To make a single-cell battery with zinc and copper, the required materials are:
1. About a foot of bare copper wire. Solid wire is best, but stranded wire will work. Thicker wire is better. Most copper wire is covered with insulation that must be removed.
2. Something that is coated with zinc (galvanized). Many steel items such as screws, nails and paperclips are zinc coated. Anything that has a silver color and is attracted to a magnet is likely zinc coated or has a coating that contains zinc.
3. A glass or plastic container that is large enough to contain the zinc item with a little extra space.
4. Enough vinegar to fill the container (preferably distilled white vinegar) or salt to mix with water.
5. Something to detect the voltage produced by the battery. An inexpensive analog multimeter similar to the one shown below can be purchased for about $15. Alternatively, the voltage can be felt as a tingle between the two wires when touched with your tongue.
6. Multimeter (optional)
Procedure
Cut the wire into two pieces. Tightly attach one piece of wire to the zinc item as shown below.
Fill the container with vinegar or salt water and insert the copper wire and zinc item as shown below. The voltage will be less than the voltage of a standard 1.5-volt dry cell. If you hold the two wires close together, but not touching, you can touch them with your tongue to feel that a voltage is produced.
Multi-cell Battery
Several cells can be connected in series to produce a higher voltage as shown below. As shown, the battery will light an LED, but it will not produce enough current to light a flashlight bulb.
Experimentation
1. What happens to the voltage when an LED or flashlight bulb is connected?
2. What happens if you use a copper wire with more surface area? Cut a longer wire and bend it together to fit in the jar.
3. For the zinc piece, try different sizes and materials.