The lithium battery inventor taught the author a thing or two about a breakthrough that has changed the world around us
In October, 2010, I found myself zipping around a test track at the research center of Hiroshi Shimizu, a professor in Keio University’s engineering department. He had built a prototype electric car, the Eliica, that could accelerate from 0 to 100 kph in four seconds and run at speeds of over 350 kph—faster than just about any car outside the super sports car segment. Prof. Shimizu didn’t let me drive, but one of his assistants took me for a spin, and seeing or “feeling,” as he would say, was believing.
Later, while discussing the car’s battery, Shimizu urged me to reach out to another researcher, an employee of Asahi Kasei named Akira Yoshino, who he predicted would one day win the Nobel Prize. I followed up in short order, requesting an interview, while trying to make myself seem more knowledgeable about battery technology than I was. The fact was, batteries are about chemistry, and chemistry was not one of my strong suits as a student.
I didn’t know, frankly, the difference between an anode and a cathode or an electrolyte and separator, the four main components of so-called rechargeable batteries. I did know that Japan was far and away the global leader in both nick-el-metal hydride and lithium-ion batteries, the two leading candidates to replace lead-acid, the industry mainstay. I also knew that Japan had staked out a leadership position in small applications such as personal computers, mobile phones and assorted power tools.
What I didn’t know at the time was that the reason for Japan’s preeminent position, in the case of lithium-ion batteries, involved Yoshino—who, while being well-known in the scientific community, was relatively unknown in the media world.
Asahi Kasei, a global chemical company, responded affirmatively to my request and we scheduled a late-afternoon interview. I arrived with an interpreter, someone well-schooled in chemistry, and we were led to a conference room.
YOSHINO ENTERED THE ROOM, and after perfunctory introductions, he immediately launched into what can best be described as a “lecture” to a college chemistry class, befitting his doctorate in engineering and master’s degree in organic chemistry. He was genial, unassuming, and focused, clearly in an educational mode.
Using a projector, he began a 15-minute slide presentation by explaining what a lithium-ion battery is. “A nonaqueous secondary battery using cabonaceous materials as a negative electrode and transition metal oxides containing lithium-ion—LiCoO2—as a positive electrode,” he said.
This “student” reporter was already lost. But the “professor” had just begun. He then reviewed the evolution of primary and secondary batteries from alkaline, lead-acid and nickel-cadmium to nickel-metal hydride, lithium-metal and lithium-ion and finally to describe the characteristics of lithium-ion batteries and why they had aroused such intense interest among global automakers.
“Small and light,” he noted, “with high electromotive force, high current discharge and no harmful substances such as cadmium or lead. And for energy storage applications: high charge/discharge efficiency and a low self-discharge rate.”
When his talk moved to electrodes, the student gave up.
Yet electrodes, the electric conductors through which current enters or leaves a battery cell, were the centerpiece of Yoshino’s research. And negative electrodes in particular were a major obstacle to mass-producing lithium-ion batteries, which by all accounts is what earned Yoshino his share of the prize.
Lest we forget, the 1980s up through the mid-1990s were the “go-go” days for the Japanese economy and, for manufacturers in general, what later came to be known as “monozukuri” production or the art of “making things.” Yoshino was representative of that period.
THIS ‘STUDENT’ REPORTER WAS ALREADY LOST. BUT THE ‘PROFESSOR’ HAD JUST BEGUN. . . . WHEN HIS TALK MOVED TO ELECTRODES, THE STUDENT GAVE UP.
Yoshino began his research in 1981, working out of a small lab south of Tokyo in Kawasaki. His Asahi Kasei team discovered that polyacetylene—an organic polymer with high electroconductivity—could be used as a negative electrode material, and filed their first big patent in 1983.
“At that time,” Yoshino recalled, “many researchers were working with metallic lithium and there were problems, the most serious being that the material is unstable and prone to overheating and fire.” He showed old lab footage in which a test sample of metallic lithium burst into flames. The polyacetylene electrode, however, did not.
HIS TEAM EVENTUALLY ADOPTED less-costly carbon as the negative electrode material, replacing polyacetylene, and filed their second big patent in 1985. Before they were done, they amassed more than 300 patents while their carbon/lithum-cobaltate battery would become the industry standard. It still is.
Upon reflection, he said, “If my team’s tests had failed I am not sure if lithium-ion batteries ever would have been mass-produced.”
By his own admission, Yoshino never envisioned a world in which we depended on notebook computers and cell phones. There were none in 1980. And electric cars were out of the question. “Our main focus was camcorders,” he said. “We simply couldn’t envision the explosive growth of cell phones and personal computers.”
Yoshino wasn’t alone in trying to achieve a technological breakthrough. Lithium-ion batteries hold four times more energy than lead-acid and a breakthrough, for auto manufacturers, for example, would lead to a move away from internal combustion engines, all of which emit CO 2 into the atmosphere, to electric powertrains, the cleanest of the clean.
In December, 2010, several weeks after our meeting, Nissan’s Leaf, which would become the best-selling electric car ever, went on sale. Interest in electric cars had grown following the 2009 Tokyo Motor Show when almost all the Japanese automakers exhibited an array of future and futuristic electric vehicles powered wholly or partly by batteries.
Since then, of course, thanks to Yoshino’s and other breakthroughs, sales have rocketed as battery costs have plummeted. Lithium batteries cost more than ¥100,000 per kWh, in 2010. Today, prices have fallen to around ¥15,000 per kWh, and Tesla and other automakers are claiming that they are fast approaching ¥10,940 per kWh—one tenth of the 2010 cost.
Experts like Yoshino are skeptical and believe that figure will be difficult to achieve in the near future, since it will depend in part on putting a recycling system in place. But that hasn’t begun in any meaningful way, and most believe it won’t be up and running until after 2025.
Let’s look at some figures.
Since 1995, global manufacturers have sold more than 5 billion personal computers, 12 billion smart phones. Since 2018, the number of electric cars sold has grown to more than 1 million units annually. And by 2030, most analysts expect sales to grow to more than 10 million, with some estimates as high as 15 million.
Battery production, which grew to an estimated 160 gigawatt-hours in 2019, is projected to grow to 1.5 terawatt-hours in 2030. That is 1.5 trillion watt-hours, mostly for the auto industry. This compares to 19 GWh (19 million watt-hours) in 2010, the year Nissan began mass-producing the Leaf.
So why was Akira Yoshino named the co-winner of the Nobel prize for chemistry? A battery expert in the US explains: Yoshino’s Asahi Kasei team “put together the fundamental structure we see in today’s lithium-ion batteries. Every lithium-ion cell in portable electronic devices on the market—computers, phones, power tools, and cameras—derives from Yoshino’s research.”
In an ironical side story, Sony beat Asahi Kasei to market by nearly a year in 1991, with a small battery for an early version of its Handycam camcorder. Asahi Kasei, a global chemical manufacturer and supplier of separators, arguably the most important component in lithium-ion batteries, pursued a different strategy. Instead of marketing its battery technology directly, reminiscent of Sony’s failed Betamax strategy in the 1970s, Asahi Kasei opted to license its technology to more than 10 battery manufacturers including Toshiba (a joint venture partner) and the former Sanyo Electric Co., now part of Panasonic.
Akira Yoshino is now teaching at Meijo University in Nagoya while still serving as a senior advisor to Asahi Kasei.
Roger Schreffler is a veteran business reporter who focuses on the auto sector, and a former FCCJ president.