Story of the world’s most powerful battery
Lithium and its ion
Lithium is a metal. It has just one electron in its outer electron shell. It is easy to remove this electron, leaving a positively charged lithium ion which is more stable than the atom. The ion forms salts; in fact, pure lithium has a tendency to catch fire and so must be stored in oil so it does not react with air. Lithium’s weakness – its reactivity – is also its strength.
In the early 1970s, Stanley Whittingham used lithium’s enormous drive to release its outer electron when he developed the first functional lithium battery. In 1980, John Goodenough doubled the battery’s potential, creating the right conditions for a vastly more powerful and useful battery. In 1985, Akira Yoshino succeeded in eliminating pure lithium from the battery, instead basing it wholly on lithium ions, which are safer than pure lithium. This made the battery workable in practice. Lithium-ion batteries have brought the greatest benefit to humankind, as they have enabled the development of laptop computers, mobile phones, electric vehicles and the storage of energy generated by solar and wind power. Ultimately this fetched them the Chemistry Nobel prize in Nov, 2019. How did they achieve all this?

Did you know?
In the mid-20th century, there were really only two types of rechargeable batteries: the heavy lead battery that had been invented 100 years earlier in 1859 (and which is still used as a starter battery in petrol-driven cars) and the nickel-cadmium battery that was developed in the first half of the 20th century.

How to tame the Lithium tiger
Whittingham was from Stanford University. He was working on solid materials with atom-sized spaces in which charged ions can attach. This phenomenon is called intercalation. The materials’ properties change when ions are caught inside them. Whittingham added potassium ions to tantalum disulphide, which is a superconductor.
He observed that it had a very high energy density. The interactions that arose between the potassium ions and the tantalum disulphide were surprisingly energy rich and, when he measured the material’s voltage, it was a couple of volts. This was better than many of that time’s batteries. Stanley Whittingham quickly realised that he could develop new technology that could store energy for the electric vehicles of the future.
However, tantalum is one of the heavier elements and the market did not need to be laden with more heavy batteries – so he replaced tantalum with titanium, an element which has similar properties but is much lighter.

Where is the Lithium? 
To have a battery, you need both positive and negative electrodes (cathodes and anodes) and lithium was a good choice of anode. That's because of its ability to give away its valence electron. The result was a rechargeable lithium battery that worked at room temperature and – literally – had great potential.

The first set-back
Unfortunately, there was a hitch: as the new lithium battery was repeatedly charged, thin whiskers of lithium grew from the lithium electrode. When they reached the other electrode, the battery short-circuited which could lead to an explosion. The fire brigade had to put out a number of fires and finally threatened to make the laboratory pay for the special chemicals used to extinguish lithium fires.
To make the battery safer, aluminium was added to the metallic lithium electrode and the electrolyte between the electrodes was changed. Stanley Whittingham announced his discovery in 1976 and the battery began to be produced on a small scale for a Swiss clockmaker that wanted to use it in solar-powered timepieces.

Enter Goodenough
John Goodenough knew about Whittingham’s revolutionary battery, and he was an inorganic chemist. His specialised knowledge told him that its cathode could have a higher potential if it was built using a metal oxide instead of a metal sulphide. His research group began to search for a suitable oxide and they were successful. Whittingham’s battery generated more than two volts, but Goodenough discovered that the battery with a cathode made of lithium cobalt oxide was almost twice as powerful, at four volts.
How did they achieve this? An old-style battery is already charged when bought in the store. But Goodenough realised that batteries did not have to be manufactured in their charged state. Instead, they could be charged afterwards. (Sounds familiar today?!) In 1980, he published the discovery of this new, energy-dense cathode material which, despite its low weight, resulted in powerful, high-capacity batteries. This was a decisive step towards the wireless revolution.

Japan and the electronic revolution
Japanese companies were looking for lightweight, rechargeable batteries that could power innovative electronics, such as video cameras, cordless telephones and computers. One person who saw this need was Akira Yoshino from the Asahi Kasei Corporation. While Goodenough’s lithium-cobalt oxide as the cathode was fine, Yoshino tried to further decrease the weight of the battery by using various carbon-based materials as the anode.

Changing the anode
Researchers had previously shown that lithium ions could be intercalated in the molecular layers in graphite, but the graphite was broken down by the battery’s electrolyte. Akira Yoshino tried using petroleum coke, a by-product of the oil industry. When he charged the petroleum coke with electrons, the lithium ions were drawn into the material. Then, when he turned on the battery, the electrons and lithium ions flowed towards the cobalt oxide in the cathode, which has a much higher potential. So the lithium ions move back and forth between the two electrodes, which gives the battery a long life.
The battery developed by Akira Yoshino is stable, lightweight, has a high capacity and produces a remarkable four volts. The greatest advantage of the lithium-ion battery is that the ions are intercalated in the electrodes. Most other batteries are based on chemical reactions in which the electrodes are slowly but surely changed.
When a lithium-ion battery is charged or used, the ions flow between the electrodes without reacting with their surroundings. This means the battery has a long life and can be charged hundreds of times before its performance deteriorates. Another big advantage is that the battery has no pure lithium, which is important for safety.
Like almost everything else, the production of lithium-ion batteries has an impact on the environment, but there are also huge environmental benefits. The battery has enabled the development of cleaner energy technologies and electric vehicles, thus contributing to reduced emissions of green-house gases and particulates. Through their work, John Goodenough, Stanley Whittingham and Akira Yoshino have created the right conditions for a wireless and fossil fuel-free society, and so brought the greatest benefit to humankind.
Source: Nobel Prize Foundation website: www.nobel.org