In June 2019, I had the opportunity to interview Akiro Yoshino, the father of the lithium-ion battery, on the fringes of the 2019 European Inventor Awards. At that time he had just won the Non-European Country category. He had already won a number of impressive prizes before that. Now he has received the highest award of all, the 2019 Nobel Prize in Chemistry.
The Nobel Prize Committee recognized the advancement of the lithium-ion battery. Its milestones can be traced back to John B. Goodenough, M. Stanley Whittingham and Yoshino. Based on the precepts of Whittingham and Goodenough, Yoshino designed the first commercially viable lithium-ion battery in 1985. This lightweight, rechargeable and high-performance battery is still used today in all mobile communication devices and in electric vehicles as well. The battery is also capable of storing significant amounts of solar and wind energy. As such, it has laid the foundation for a wireless, fossil fuel-free society.
In that interview I had with him in June, I also spoke to him about sustainable trends in battery research. At the time, he called for the development of recycling processes for lithium-ion batteries. Read the full interview here:
Yoshino began developing rechargeable batteries in 1981 at a time when batteries were large, heavy and expensive and were not suitable for powering mobile electronic devices. Lighter alternatives based on lithium often exploded or caught fire. Yoshino completely dispensed with lithium metal in the anode battery. Instead, he used a safe, electrically conductive plastic: polyacetylene. He later substituted this with a carbon compound. He then switched the cathode material for lithium cobalt oxide. In addition, he integrated a heat-sensitive polyethylene-based film between the reactive layers. This film melts when the battery becomes too hot, acting as a fuse which prevents the entire battery structure from burning.
The lithium-ion battery patent as we know it today was filed by Yoshino in 1983. In 1991, Sony and Asahi were the first companies to commercialize the lithium-ion battery. Until 2016, Asahi Kasei’s world market share for lithium-ion battery separators was 17 %. In 2017, the global market value for lithium-ion batteries was estimated at 26.5 billion euros. A growth of more than eighty billion euros has been projected for 2025.
You’ve filed sixty patents so far. Are all these patents part of the lithium-ion battery sector?
Yes, all sixty patents are for lithium-ion batteries. These patents are valid for twenty years. Some have already expired, others are still in effect. But all of the technologies are still in use.
What fascinates you most about your research field?
(Laughs) What makes me happy is the fact that new markets are constantly emerging for the technologies I have been developing. Some of these new markets are just appearing. The first devices which required small, lightweight, rechargeable batteries were mobile phones and laptops. Now a new market is emerging for electric vehicles. I find this development incredible and it makes me happy to work in another field with so much potential.
They are still working on improving the safety and efficiency of lithium-ion batteries. What is your current research problem?
Safety is a critical and crucial parameter. We are therefore continuing our research in this area. I think that the solid-state battery will be a big step forward in terms of safety – but also in terms of efficiency. This is a new field.
The lithium-ion battery is still the most efficient. But there are also efforts to develop new battery types – like the magnesium battery at the Helmholtz Institute. How do you feel about that?
It remains to be seen how these new alternative technologies will develop and whether they will make a breakthrough. That’s what matters. What we definitely can say is that the solid-state battery has made a breakthrough. Note that for solid-state batteries, both the electrode and electrolyte types are made of a solid (non-liquid) material. They are quick to load and are non-flammable.
In Europe, there is also research on sustainable batteries, such as those made from leftovers from apples. A research project at the Helmholtz Institute has led to this research. What do you think about sustainability in rechargeable batteries?
(Laughs) When it comes to the sustainability of batteries, there are two approaches: First, a battery must do its job and provide the best possible storage capacity for electricity. This guarantees high efficiency and sustainable use of electricity. The next question is: How to make the battery itself sustainable. We need to develop recycling technologies for batteries. We do not use lithium metal in our anodes. However, the cathode in particular, where we use lithium cobalt oxide, must be recycled.
About Akira Yoshino
Born in 1948 in Suita (Osaka), Yoshino studied petrochemistry and earned a doctorate in engineering. Since 1972 he has been working for the chemical group Asahi Kasei in the Tokyo prefecture. Today he holds the position of General Manager of the Yoshino Laboratory and is also the president of the Lithium-Ion Battery Technology and Evaluation Center (LIBTEC). Since 2017, the researcher has also been a professor at the private Meijō University in the Aichi prefecture. He has already been awarded several prestigious prizes for his work. Yoshino is a Fellow of the Chemical Society of Japan. In 2013 he received the Global Energy Prize (Russia) in 2013, the Charles-Stark-Draper-Prize from the United States National Academy of Engineering in 2014, and the Japan Prize in 2018. Last but certainly not least, in October 2019, Akira Yoshino has received the Nobel Prize in Chemistry.