When a Nobel laureate in chemistry endorses a battery

[The Conversation] - Published on January 6, 2020 in Science and Society

It is no coincidence that the 2019 Nobel Prize in Chemistry was awarded to the pioneers of the lithium-ion battery.

Laure Monconduit, University of Montpellier

This type of battery currently powers smartphones and laptops, cameras, MP3 players, and the vast majority of electric and hybrid vehicles currently on the market, while opening up new horizons in renewable energy storage. In other words, as Jean-Marie Tarascon, professor at the Collège de France and holder of the Chair of Solid-State and Energy Chemistry, recently stated on a television channel, “it is one of the great advances of the last century, alongside the transistor and fiber optics.”

Three Men for a Nobel Prize

Three men were awarded this prize on October 9: the Anglo-American Michael Stanley Whittingham, the American John Bannister Goodenough, and the Japanese Akira Yoshino. These three researchers, who are well known to all scientists working in the fields of chemistry and materials physics and chemistry, have been making significant contributions to the field of energy storage for over forty years. And they are, of course, responsible for numerous breakthroughs in the field of lithium-ion batteries.

It all began in the 1970s with the work of chemist M. S. Whittingham. A graduate of the University of Oxford, where he earned his bachelor’s, master’s, and doctoral degrees, he first completed a postdoctoral fellowship at Stanford University before joining Exxon Research and Engineering in 1972. There, for 16 years, he worked on developing energy sources that did not rely on fossil fuels. He then joined Schlumberger, before being appointed professor at Binghamton University in 1988.

Based on research into so-called superconducting materials, he discovered one that was particularly interesting: titanium disulfide (_TiS₂). As early as 1965, the German chemist Walter Rüdorff had demonstrated the possibility of intercalating lithium ions (Li⁺) in solution into_TiS₂. However, the French chemist Jean Rouxel, and later M. S. Whittingham himself along with his Exxon colleague, the American Fred R. Gamble, subsequently proved that it was possible to intercalate more lithium into titanium disulfide than Rüdorff had done, without significantly altering the material’s crystallographic structure.

In fact, as early as 1973, M.S. Whittingham had discovered that the intercalation of lithium into an electrochemical cell was a reversible process. Titanium disulfide, with its layered structure, could therefore serve as an ideal material for a rechargeable lithium battery. The principle works as follows: lithium ions, released by an anode (negative electrode) made of metallic lithium, are stored at the cathode (positive electrode) between the layers of titanium disulfide. The first rechargeable lithium battery was born, with a voltage exceeding 2 volts.

A new material: cobalt oxide

For his part, the American J.B. Goodenough earned his Ph.D. in physics in 1952 from the University of Chicago. Initially a researcher at the Massachusetts Institute of Technology (MIT) laboratory, he worked with his team on computer random-access memory, also known as magnetic random-access memory. He then became head of the inorganic chemistry laboratory at the University of Oxford, where he developed a material for the cathode of the rechargeable lithium-ion battery (cobalt oxide), before joining the University of Texas at Austin in 1986, in the mechanical and electrical engineering departments of the Cockrell School of Engineering: where he remains very active, having recently published, along with his team, very promising results for a battery in which the electrolyte would be solid, thereby improving safety.

His work on cobalt oxide, as a replacement for titanium disulfide, paved the way for batteries capable of delivering a voltage of 4 volts. And this cathode material has been used in nearly all commercial batteries. However, this battery, which used a lithium metal anode, proved too dangerous, with a risk of lithium dendrite formation that could cause the cathode and anode to come into contact, leading to short circuits or even an explosion. It was therefore quickly withdrawn from the market.

The first commercially available lithium-ion battery

The last of the three researchers awarded the Nobel Prize in Chemistry, Akira Yoshino, first earned a master’s degree in engineering from Kyoto University in 1972, before devoting several years to archaeology. But he returned to his first love and earned a doctorate in engineering from Osaka University in 2005. And it was he who, in 1986, developed the first commercially viable lithium-ion battery, a battery in which the overly reactive lithium anode had been replaced by a carbon-based anode (petroleum coke), into which lithium ions could be inserted.

Replacing lithium metal with carbon extended the battery’s runtime while improving its safety. But above all, it was the essential step toward bringing the technology to market. Sony was the first to commercialize this technology in 1991, using cobalt dioxide and lithium as the cathode and carbon as the anode. Many other companies followed suit, including Toyota, LG, Samsung, Panasonic, and others.

With a global race for battery technology now in full swing, the 2019 Nobel Prize in Chemistry highlights the importance of research in the field of energy storage. This research is all the more important given the need to store energy in a “clean” way—without relying on fossil fuels—and thereby help combat global warming.

Laure Monconduit, Researcher – DR1, AIME Team, University of Montpellier

This article is republished from The Conversation under a Creative Commons license. Readthe original article.

Keywords: Economy, Innovation, Research, Science