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The history of batteries
BATTERIES are so ubiquitous today that they’re almost invisible to us.
Yet they are a remarkable invention with a long and storied history, and an equally exciting future.
A battery is essentially a device that stores chemical energy that is converted into electricity. Basically, batteries are small chemical reactors, with the reaction producing electrons, ready to flow through an electircal device.
Batteries have been with us for a long time. In 1938 the Director of the Baghdad Museum found what is now referred to as the “Baghdad Battery” in the basement of the museum.
Analysis dated it at around 250BC and of Mesopotamian origin.
Controversy surrounds this earliest example of a battery but suggested uses may have included electroplating, pain relief or a religious tingling experience.
American scientist and inventor Benjamin Franklin first used the term “battery” in 1749 when he was doing experiments with electricity using a set of linked capacitors.
The first true battery was invented by the Italian physicist Alessandro Volta in 1800.
Volta stacked copper (Cu) and zinc (Zn) discs, separated by cloth soaked in salty water.
Wires connected to either end of the stack produced a continuous stable current.
Each cell (a set of a Copper and Zinc discs and the salt water) produces 0.76 Volts (V).
A multiple of this value is obtained by stacking a number of these cells together.
One of the most enduring batteries - the lead-acid battery - was invented in 1859 and is still the technology used to start most internal combustion engine cars today.
It is the oldest example of rechargeable battery.
In 1980, the American physicist and prolific inventor Professor John Goodenough devised a new type of lithium battery in which the lithium (Li) could migrate through the battery from one electrode to the other as a Li+ ion.
Lithium is one of the lightest elements in the periodic table and it has one of the largest electrochemical potentials, therefore this combination produces some of the highest possible voltages in the most compact and lightest volumes.
Depending on the transition metal used in the lithiumion battery, the cell can have a higher capacity, but can be more reactive and susceptible to a phenomenon known as thermal runaway.
In the case of lithium cobalt oxide (LiCoO2) batteries made by Sony in the 1990s, this led to many such batteries catching fire, and caused a bit of chaos with multiple devices recalled.
As such, the possibility of making battery cathodes from nano-scale material, and hence more reactive, was out of the question.
But in the 1990s Goodenough again made a huge leap in battery technology by introducing a stable lithium-ion cathode based on lithium iron and phosphate.
This cathode is thermally stable. It also means that nano-scale lithium iron phosphate (LiFePO4) or lithium ferro phosphate (LFP) materials can now be made safely into large format cells that can be rapidly charged and discharged.
And now, John Goodenough, might just be about the reinvent the wheel again with solid state batteries - a promising technology that we’ll look into further next week when we discuss the future of batteries.