The invention of rechargeable batteries: An interview with Dr. Akira Yoshino, 2019 Nobel laureate

• Author: Tomoki Sawai
• Position: WIPO Japan Office

Dr. Yoshino invented and patented the world’s first lithium-ion battery and has since worked continuously to improve the technology. He has secured over 60 patents on lithium-ion battery technology during his career. Dr. Yoshino talks about the challenges he overcame in developing lithium-ion batteries and the role that strategic use of patents rights has played in building a booming global market for them.

What motivated you to take up chemistry?

I have always been interested in the natural world. And when I was in elementary school one of my teachers suggested that I read The Chemical History of a Candle by Michael Faraday. And that stirred up a lot of questions for me. I hadn’t been interested in chemistry until then. That’s how it all started. I then went on to study quantum organic chemistry at the University of Kyoto.

And how did you come to work on lithium-ion batteries?

In the early 1970s, I joined the Exploratory Research Team at Asahi Kasei Corporation to explore new general-purpose materials. The projects I worked on initially didn’t work out, so I was looking for a new research focus. At the time, there was great interest in polyacetylene, a fascinating electro-conductive polymer that had been predicted by Dr. Kenichi Fukui, Japan’s first Nobel Laureate in Chemistry, and discovered by Dr. Hideki Shirakawa, winner of the 2000 Nobel Prize for Chemistry.

At first, I explored practical applications for polyacetylene. But at the time, Japan’s electronics industry was looking for a new lightweight and compact rechargeable battery to power the mobile devices they were developing. Many researchers were working on this, but existing anode materials were unstable and raised serious safety concerns – a new anode material was required. My research on polyacetylene suggested that it could be used as an anode material (because lithium-like cations move in and out of it), so I started experimenting with it and it worked.

My basic research on lithium-ion batteries began in earnest in 1981, the year Professor Fukui won the Nobel Prize for Chemistry. Interestingly, research into lithium-ion batteries has been supported by eight Nobel laureates, which gives an indication of how challenging their development has been.

By 1983, I had come up with a new type of rechargeable battery using a combination of polyacetylene for the anode and lithium cobalt oxide for the cathode. Dr. John Goodenough, one of my fellow laureates, had identified lithium cobalt oxide, the first cathode material to contain lithium ions, in 1980.

How did your research evolve following this breakthrough?

All went well for a while. The prototype was one-third lighter than a standard nickel-cadmium battery, which was good, but we only achieved a slight weight reduction and were unable to reduce the size of the battery. This put the whole venture into question...