AsianScientist (Apr. 28, 2021) – Anybody over the age of 30 has lived through the remarkable growth and transformation of the rechargeable lithium-ion battery (LIB). When Sony first commercialized it in 1991, it was mostly early adopters and video-camera enthusiasts who came into contact with it.
Yet by miniaturizing energy storage, while negating the need to change single-use batteries, the LIB has powered the consumer electronics boom of the past three decades. This includes everything from Palm Pilots, iPods and early Nokia phones to laptops, smartphones, drones and, most recently, electric vehicles (EVs).
In 2010, the LIB market, in terms of GWh capacity, was almost exclusively comprised of ‘mobile IT’ devices. By 2017, EVs had overtaken mobile IT. And by 2025, EVs will completely dominate the LIB market despite accounting for just 15 percent of new car sales, according to Akira Yoshino, chemistry professor at Meijo University and one of three to win the 2019 Nobel Prize in Chemistry (colloquially known as the ‘lithium-ion trio’).
Yoshino says the EV evolution is proof that LIBs will sit at the heart of a future society defined by its emphasis on mobile IT and sustainability.
“This is the reason for this award,” he said in his Nobel acceptance speech.
Yoshino was born in 1948 in Suita, post-war Japan. There, as a little boy, his interest in chemistry was sparked by reading The Chemical History of a Candle by Michael Faraday. The four best decisions of his life, he says, were: studying petrochemistry at Kyoto University and graduating in 1970; joining Asahi Kasei Corporation in 1972; getting married in 1973; and beginning basic LIB research in 1981 at Asahi (where Yoshino spent his entire career—only the second of Japan’s eight chemistry laureates to come from industry rather than academia).
“The Chinese characters for chemistry are 化学 (kagaku) and these characters mean that ‘one thing transforms into another thing,’” he once said. “It’s this process of transformation that really interested me.”
In 1985, Yoshino created the world’s first commercially viable lithium-ion battery by using polyacetylene, an organic substance that can conduct electricity, as the anode and cobalt oxide the cathode. The cobalt oxide was the brainchild of John Goodenough, one of the trio. (The last, Stanley Whittingham, in the 1970s discovered how electricity could be generated by holding lithium ions between titanium sulfide plates.)
Yoshino separated the anode and cathode with a thin, porous polyethylene-based membrane, and in doing so, overcame a critical safety barrier in lithium-ion batteries: overheating would hitherto melt the membrane and prevent further electrochemical reactions. Among his numerous other subsequent improvements was the development of an aluminum foil current collector.
Yoshino believes that one of the LIB’s main contributions to a fossil-free future is its ability to moderate renewable energy fluctuations.
“The lithium-ion battery plays an important role since it can store surplus energy (from renewable sources) and supply it when necessary. Thus, as a result, the development of the lithium-ion battery will help the growth of renewable energy,” he told The Japan Times.
While today’s electric vehicle LIBs have almost reached adequate performance in terms of energy density and cost, Yoshino says there is still a long way to go in terms of durability—ideally 600,000 km, or 5,000 cycles.
Finally, in a world where global sustainability initiatives are often undermined by international disagreements or divides, it is heartening to see scientific researchers building on the achievements of those far away. The lithium-ion trio are from Japan, the UK (Whittingham) and the US (Goodenough). Yoshino says that he has a ‘parent-child’ relationship with Goodenough, 26 years his senior.
It is telling that Yoshino wears two badges on the lapel of his suit: one bearing the name of Asahi Kaisei, his Japanese lifelong employer; and the other a multicolored wheel denoting the United Nation’s 17 sustainable development goals, which, if they are indeed to be achieved by 2030, will be in no small part thanks to the lithium-ion battery.
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Copyright: Asian Scientist Magazine; Illustration: Lianne Chua.
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