In-depth interview: dialogue with pioneers of lithium-ion batteries

Lithium-ion batteries - the kind of your phone, laptop and electric car - completely changed the calculations. These batteries are also changing transportation and power grids.

Some of the key features of modern lithium-ion batteries date back to work in Japan in the 1980s, including chemist Akira Yoshino, who helped the chemical giant Asahi Kasai develop some important breakthroughs. Yoshino's work helped produce lithium-ion batteries using carbon and lithium cobalt oxide, and was able to hold more energy than the standard mobile battery of the time.

For his scientific contribution, Yoshino received the Japan Prize earlier this month, a prestigious award given to several scientists and inventors of any nationality each year. Last week, he participated in a celebration attended by the Japanese Emperor Akihito and Empress Michiko to win his award.

A few weeks before the ceremony began I talked to Yoshino, 70, through his office in Tokyo. This is a conversation that is easy to edit and translate.

Fehrenbacher: When I started research many years ago, please tell me about the status of rechargeable batteries. At what time is the battery available?

Yoshino: This was in 1981, 35 years ago, when I started researching batteries. At that time, it was a nickel-cadmium secondary battery that could be used to move a rechargeable battery.

Fehrenbacher: Why is the battery powered?

Yoshino: It was used to charge relatively small electronic devices such as portable radios.

Fehrenbacher: What made you discover the breakthrough of lithium-ion batteries - carbon and lithium cobalt oxide and battery design?

Yoshino: In 1981, the only battery available was nickel cadmium. However, research and development activities at the time were very active in promoting small-sized batteries. But unfortunately, all these research and development efforts have failed.

This is related to the problems associated with the materials used for the anode. The research project is not completely focused on batteries. It begins with a study of polyacetylene [conductive polymer] through which current can flow. Since this is a material through which lithium ions can pass, it is possible to develop an anode for a secondary battery.

In order to develop a battery made of polyacetylene with an anode, the only material that is suitable and available for the cathode is lithium cobaltate. This development was achieved in 1983.

But we continue to evaluate and research and eventually replace the anode material with carbon instead of polyacetylene. This is how you developed lithium-ion batteries today.

Fehrenbacher: For readers who don't know the details of lithium-ion batteries, what do these details do in the battery?

Yoshino: I want to say that the biggest achievement of this breakthrough is that we have created a small and light battery.

The reason behind this major achievement is related to the high voltage in the battery. In the case of a lithium ion battery, its voltage is 4.2 volts. However, in the case of a nickel-cadmium battery, it is only 1.2 volts. I will say that this is the main or biggest advantage or achievement we have achieved.

Fehrenbacher: When you saw the lithium-ion battery market today, are you surprised that its development is so great, is it so important for computers and mobile phones based on these core breakthroughs?

Yoshino: Back in 1985, when we promoted research and development around this battery, our market for batteries was the camera.

The market size of the camera is about 1 million batteries per month. At the time I thought this was a very big market.

The batteries currently available in the total demand for cameras for the recorder market account for only 0.2% of the total battery market. This means that the market we envision at the time actually became 500 times.

Fehrenbacher: Is the battery research you see today particularly interesting for the next generation of batteries?

Yoshino: I want to say that in the past few years, I have made a major breakthrough in the field of solid-state batteries.

The advantage of solid-state batteries is that they have proven to be excellent compared to expectations for output performance and low temperature performance.

From a scientific point of view, we are now seeing interest and research in the basics of lithium-ion battery behavior.

Fehrenbacher: What inspired you to become a chemist and work in energy storage?

Yoshino: I got the first inspiration for science from the elementary school teacher. The teacher is a chemist who taught me a lot about chemistry. He also suggested that I read [Michael] Faraday's book titled "Chemical History of Candles", which is considered an important reading in the field.

Fehrenbacher: What advice do you have for young people who are interested in science, chemistry and battery technology?

Yoshino: Today's society is revolving around the Internet, and we are faced with a lot of information.

Young people tend to misunderstand that there is nothing to explore in the natural sciences, because everything has been discovered and clarified. But I will say that reality is the opposite. In the entire discipline of the natural sciences, what humans have articulated is only a small part of it.

Fehrenbacher: In addition to your battery invention, what is the source of inspiration in your life?

Yoshino: Outside of science, the area I am particularly interested in is history. The reason I am interested in history is that it involves events that happened in the past, which means that there is already an answer.

So if you study history, you will find out how to implement this answer. In this regard, I feel that you have a lot in common with regard to history and the way in which science and science develop.

Fehrenbacher: The Japanese awards ceremony is coming soon. Are you excited? What is your plan?

Yoshino: Yes, I am looking forward to this event. I was invited to attend the grand dinner that his Royal Highness of Japan will attend, and I was fortunate enough to sit next to him.

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