Li-ion batteries: Science 'directly into your hand'

Updated 14 Oct, 2019

On Wednesday, John Goodenough, Stanley Whittingham and Akira Yoshino, the inventors of a technology taken for granted by most, got the most prestigious chemistry nod of all: a Nobel Prize. "They created a rechargeable world," stated the Royal Swedish Academy of Sciences, which awards the accolade.

Only commercialised in 1991, lithium ion batteries now power millions upon millions of cellphones, laptops, tablets, cameras, hearing aids, pacemakers, solar panels, scooters, bikes and even long-distance electric cars. "Over two thirds of the world's population own a mobile device be it a smartphone, a laptop or tablet, and nearly all powered by rechargeable lithium-ion batteries. They are the hidden workhorses of the mobile era," Paul Coxon of the University of Cambridge's Department of Materials Science and Metallurgy told AFP.

They have considerably boosted human mobility, and allowed millions in developing countries to access information and services online with just a mobile phone.

Lithium-ion batteries have also reduced our reliance on planet-warming fossil fuels, especially in electric cars.

Furthermore, they can be used in combination with renewable but fluctuating energy sources such as the Sun or wind, capturing and storing energy to be re-used later.

For Coxon, the lithium ion battery is a worthy Nobel recipient as it plays to the very origins of the prestigious prize. "The practical application of science for the benefit of humanity; fundamental science placed directly into your hand," he said. "I am literally holding a phone in my hand right now."

Unlike their predecessor, lead acid batteries developed in the mid-19th century, li-ion batteries are rechargeable. They are smaller, lighter, longer lasting and can be made to be more powerful. Electric car batteries "no longer weigh two tonnes but 300 kilogrammes (660 pounds)," said Sara Snogerup Linse, a professor in physical chemistry and a member of the Nobel Committee for Chemistry.

When a battery is connected to a circuit, charged ions move inside the battery, usually in a chemical solution, between two electrodes - an anode and a cathode. Chemical reactions take place at each of the electrodes, creating a buildup of electrons on one end. The electrons seek to rebalance, but cannot move through the battery, forcing them to travel through the circuit, giving off electric energy. The positive electrode is made from a composite of lithium - the lightest metal known to man and the key to the design's success, according to Olof Ramstroem, a fellow committee member.

"Lithium has such enormously attractive properties and that means you can get a very lightweight battery that is small with high power and efficiency," he said after Wednesday's announcement in Stockholm. "Lithium is very reactive... which is what we need - we need the electrons from the lithium. This is all about trying to tame that and get it into that small battery package that is really useful to us."

Copyright Agence France-Presse, 2019

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