The 2019 Nobel Prize in Chemistry has been awarded to Stanley Whittingham, John Goodenough and Akira Yoshino for their development of the lithium-ion battery. The three scientists over their respective careers have shaped up what is the now the most-preferred battery across all rechargeable devices such as smartphones, laptops and electric vehicles. These batteries are lightweight, rechargeable and powerful and, besides being compact in size, they can store significant amounts of energy from solar and wind power.
What has each scientist contributed?
The foundation of lithium-ion batteries was laid back in the 1970s during the oil crisis. Stanley Whittingham, an English-American scientist, worked towards developing methods by which fossil-fuel-free technologies could be made. He began to research superconductors and discovered a highly energy-rich material, that he used for creating an innovative cathode in a lithium battery. This cathode was made from titanium disulphide which, at the molecular level, has spaces that can contain – intercalate – lithium ions. The anode of the battery was made partially from metallic lithium. This led to a battery that had a potential of over 2 volts. But, metallic lithium is reactive and the battery was too explosive to be used.
Around this time, John Goodenough, an American scientist, had predicted that a cathode would have greater potential if it was made by using a metal oxide instead of metal sulphide. In 1980, following a systematic search, Goodenough demonstrated cobalt oxide with intercalated lithium ions could produce as much as 4 volts. This was a key breakthrough in the field of batteries and would lead to the creation of much-powerful batteries.
Using Goodenough’s cathode as basis, Japanese chemist Akira Yoshino made the first commercially viable lithium-ion battery in 1985. Instead of using reactive lithium in the anode, he used petroleum coke, a carbon material, which can intercalate lithium ions just like the cathode’s cobalt oxide. As a result, a lightweight, hardwearing battery was created which could get charged hundreds of times before the performance of the battery deteriorated. Lithium-ion batteries have an advantage that they are not based on the chemical reactions which break down electrodes. Instead, they are based on the lithium ions that are flowing back and forth between the anode and cathode of the battery.
How does a lithium-ion battery function?
These days there are four key components inside a lithium-ion battery: the cathode which has lithium on the positive electrode, the anode which contains graphite on the negative electrode, an electrolyte which acts as a catalyst and electron barrier, and an outer circuit by which the electrons move. When in use, the ions inside the battery move from the anode to the cathode forcing the electrons to do the same, in this process the power is supplied to the smartphone. When the phone is put on charge, the ions and electrons move in a reverse flow that is from the lithium cathode to the graphite anode where the charge is stored.
Where all is lithium-ion battery used?
Ever since lithium-ion batteries were launched in the market back in 1991, they have revolutionised the way humans use portable devices. Today, lithium-ion batteries are used in almost all types of gadgets such as smartphones, laptops, electric vehicles, cameras, smartwatches and more.