Our History of Batteries Begins with the Baghdad Battery
Why was a battery required 2000 years ago?
In June 1936, workers constructing a new railway near the city of Baghdad uncovered an ancient tomb. Relics in the tomb allowed archeologists to identify it as belonging to the Parthian Empire. The Parthians, although illiterate and nomadic, were the dominating force in the Fertile Crescent area between 190 BC to 224 AD. It is known that in 129 BC they had acquired lands up to the banks of the Tigris River, near Baghdad.
Among the relics found in the tomb was a clay jar or vase, sealed with a pitch at its top opening. An iron rod protruded from the center, surrounded by a cylindrical tube made of wrapped copper sheet. The height of the jar was about 15 cm, and the copper tube was about 4 cm diameter by 12 cm in length. Tests of replicas, when filled with an acidic liquid such as vinegar, showed it could have produced between 1.5 and 2 volts between the iron and copper. It is suspected that this early battery, or more than one in series, may have been used to electroplate gold onto silver artifacts.
A German archeologist, Dr. Wilhelm Konig, identified the clay pot as a possible battery in 1938. While its 2000-year old date would make it the first documented battery invention, there may have been even earlier technology at work. Dr. Konig also found Sumerian vases made of copper, but plated with silver, dating back to 2500 BC. No evidence of Sumerian batteries has been found to date.
1747 – Principle of the telegraph discovered, but not battery-powered.
In 1747 Sir William Watson demonstrated in England that a current could be sent through a long wire, using the conduction through the earth as the other conductor of the circuit. Presumably, the current was from electrostatic discharge, such as from a Leyden jar charged with high voltage. People at that time knew how to generate electrostatic voltages by rubbing dissimilar materials such as glass and fur together. Then in 1753, a certain C.M. in Scotland devised a signaling machine that used an insulated wire for each letter of the alphabet. At the sending end, an electrostatic charge was applied to the selected wire, and a pith ball jumped at the receiving end in response to the voltage.
1786 – Luigi Galvani notices the reaction of frog legs to voltage
He was remarkably close to discovering the principle of the battery but missed it. He thought the reaction was due to a property of the tissues. He used two dissimilar metals in contact with a moist substance to touch dissected frog legs. The resulting current made the muscles in the frog legs twitch. Luigi Galvani made many more important discoveries later when the relationship between magnets and currents became known. The galvanometer is named for him. It is a moving coil set in a permanent magnetic field. Current flowing through the coil deflects it and an attached mirror, which reflects a beam of light. It was the first accurate electrical measuring instrument.
1800 – Alessandro Volta publishes details of a battery
That battery was made by piling up layers of silver, paper or cloth soaked in salt, and zinc. Many triple layers were assembled into a tall pile, without paper or cloth between zinc and silver, until the desired voltage was reached. Even today the French word for the battery is ‘pile’ (English pronunciation “peel”.) Volta also developed the concept of the electrochemical series, which ranks the potential produced when various metals are in contact with an electrolyte. How handy for us that he was well known for his publications and received recognition for this through the naming of the standard unit of electric potential as the volt. Otherwise, we would have to ask “How many galvans does your battery produce?” instead of asking “how many volts does your battery produce?”
1820 – The Daniell Cell
The Voltaic Pile was not good for delivering currents for long periods of time. This restriction was overcome in the Daniell Cell. British researcher John Frederich Daniell developed an arrangement where a copper plate was located at the bottom of a wide-mouthed jar. A cast zinc piece commonly referred to as a crowfoot, because of its shape, was located at the top of the plate, hanging on the rim of the jar. Two electrolytes, or conducting liquids, were employed. A saturated copper sulfate solution covered the copper plate and extended halfway up the remaining distance toward the zinc piece. Then a zinc sulfate solution, a less dense liquid, was carefully poured in to float above the copper sulfate and immerse the zinc. As an alternative to zinc sulfate, magnesium sulfate or dilute sulphuric acid was sometimes used. The Daniell Cell was one of the first to incorporate mercury, by amalgamating it with the zinc anode to reduce corrosion when the batteries were not in use. We now know better than to put mercury into batteries. This battery, which produced about 1.1 volts, was used to power telegraphs, telephones, and even to ring doorbells in homes for over 100 years. The applications were all stationary ones because motion would mix the two electrolyte liquids. The battery jars have become collector’s items, with prices ranging for $4 to $44. Check them out on ebay.com.
1859 – Lead Acid – the Planté Battery
Raymond Gaston Planté made a cell by rolling up two strips of lead sheet separated by pieces of flannel, and the whole assembly was immersed in dilute sulphuric acid. By alternately charging and discharging this cell, its ability to supply current was increased. An improved separator was obviously needed to resist the sulphuric acid.
1866 – The Leclanché carbon-zinc battery
The first cell developed by Georges Leclanché in France was a wet cell having its electrodes immersed in a liquid. Nevertheless, it was rugged and easy to manufacture and had a good shelf life. He later improved the battery by substituting a moist ammonium chloride paste for the liquid electrolyte and sealing the battery. The resulting battery was referred to as a dry cell.
It could be used in various positions and moved about without spilling. Carbon-zinc dry cells are sold to this day in blister packages labeled “heavy-duty” and “transistor power”. The anode of the cell was zinc, which was made into a cup or can which contained the other parts of the battery. The cathode was a mixture of 8 parts manganese dioxide with one part of carbon black, connected to the positive post or button at the top of the battery by a carbon collector rod. The electrolyte paste may also contain some zinc chloride. Around 1960 sales of Leclanché cells were surpassed by the newer alkaline-manganese batteries.
1881 – Camille Faure’s Lead Acid Battery – Suitable for Autos
Camille Faure’s acid battery used a grid of cast lead packed with lead oxide paste, instead of lead sheets. This improved its ability to supply current. It formed the basis of the modern lead-acid battery used in autos, particularly when new separator materials were developed to hold the positive plates in place and prevent particles falling from these plates from shorting out the positive and negative plates from the conductive sediment.
1898 to 1908 – the Edison Battery
Thomas Edison, the most prolific of all American inventors, developed an alkaline cell with the iron as the anode material (-) and nickelic oxide as the cathode material (+). The electrolyte used was potassium hydroxide, the same as in modern nickel-cadmium and alkaline batteries. The cells were well suited to industrial and railroad use. They survived being overcharged or remaining uncharged for long periods of time. Their voltage (1 to 1.35 volts) was an indication of their state of charge.
1893 to 1909 – the Nickel-Cadmium Battery
In parallel with the work of Edison, but independently, Jungner and Berg in Sweden developed the nickel-cadmium cell. In place of the iron used in the Edison cell, they used cadmium, with the result that it operated better at low temperatures, self-discharged itself to a lesser degree than the Edison cell, and could be trickle-charged, that is, charged at a much-reduced rate. In a different format and using the same chemistry, nickel-cadmium cells are still made and sold.
1949 – the Alkaline-Manganese Battery
The alkaline-manganese battery, or as we know it today, the alkaline battery, was developed in 1949 by Lew Urry at the Eveready Battery Company Laboratory in Parma, Ohio. Alkaline batteries could supply more total energy at higher currents than the Leclanché batteries. Further improvements since then have increased the energy storage within a given size package.
1950 – The zinc-mercuric oxide alkaline battery by Ruben
Samuel Ruben (an independent inventor) developed the zinc-mercuric oxide alkaline battery, which was licensed to the P.R. Mallory Co. later became Duracell, International. Mercury compounds have since been eliminated from batteries to protect the environment.
1964 – Duracell is formed (incorporated)