The Powerhouse: Inside the Invention of a Battery to Save the World (5 page)

I
n the early 1990s, the researchers at Argonne’s Building 205 were griping openly about oppressive management. The Department of Energy wanted invention on demand but also mandated excessive safety training, the combined impact of which was to “discourage spontaneity.” The lab was no longer as secretive—since Argonne was working on so many nonnuclear projects, it had abandoned the practice of declaring everything classified. Much of the work remained confidential, as basic invention was under way, but often did not involve matters of national security. Scientists no longer had to wear color-coded shoes to protect against nuclear contamination. They could take food and coffee into their offices. And their offices were air-conditioned.
1

Still, you could not enter or move around Argonne without a lab identification badge. They hung by a string from everybody’s neck. Many were imprinted with the word “
COUNTERINTELLIGENCE
.” The IDs were mildly jarring in that the photographs often showed a much younger, college-age version of the scientist. In his, Chamberlain resembled a California surfer, with brushed-back hair that could be mistaken for blond. His hair had long since grayed.

Of course it was no crime to brandish a dated photograph, such as Chris Johnson’s. He had spent his entire career at Argonne. Now in his forties and fullish, Johnson was once a slim professional with a stylishly trimmed beard. You could imagine the go-getting young scientist who, working with Thackeray as his chief researcher, coinvented Argonne’s NMC almost a decade and a half before.

Johnson was an unpretentious and earthy Ohioan. His father taught high school chemistry and strewed science textbooks about the house, but he did not press the subject on the boy. “I just want you to feel like it’s not work when you get up and go to your job,” he told his son. So Johnson did not at first grow up as a science geek. He did not puzzle over test tubes in the garage or ponder garden insects underneath a microscope. But when he reached high school, a science teacher’s enthusiasm infected him, which led Johnson to major in chemistry at the University of North Carolina. There, in the electrochemistry lab, Johnson felt in his element.

In 1991, Johnson joined Argonne as a postdoctoral assistant. Sony had just commercialized lithium-ion.

As he briefed himself by reading scientific journals, Johnson noticed copycat behavior. Papers fixated on the fashion of the day—the Goodenough lithium-cobalt-oxide cathode that had enabled Sony’s new batteries. None seemed to pose daring new ideas—they only plumbed how to make lithium-cobalt-oxide better, and even when they did that, their science seemed “lacking.” But one chemist stood out—Mike Thackeray, who was working back in South Africa after his Oxford stint. Thackeray was talking about his alternate system—manganese oxide, which he said would cost less than lithium-cobalt-oxide. In Johnson’s view, only Thackeray seemed prepared to say something original and produce the data to back it up.

About this time, Thackeray’s South Africa bosses informed him that they were shutting down his lithium-ion program. Notwithstanding Sony’s coup, the lab did not foresee sufficient sales in the lithium-ion play. Thackeray debated the point, but the decision was made. He was to find other projects.

In 1993, Thackeray met a talkative American named Don Vissers at a battery conference in Toronto. Vissers was a senior manager in Argonne’s Battery Department. He and Thackeray agreed that the market for lithium-ion batteries was bound to swell. Yet both were frustratingly on the outside in this discernible trend: while South Africa was erring by abandoning lithium-ion, Argonne was falling behind because of its passiveness in the same field. The Chicago lab continued to work on high-temperature sulfur batteries and had yet to make its own push in the new technology. Vissers suggested that they had a common cause. So why didn’t Thackeray consider a move to Chicago and taking Argonne into the science of lithium-ion?

Thackeray pondered it and a year or so later agreed.

 • • • 

Thackeray’s wife, Lisa, dreaded moving to an unfamiliar land where none of them—not they or their three daughters—knew a soul. Thackeray described reaching O’Hare that February: “As the American Airlines aircraft approached the landing strip with the wheels a few feet from touchdown, the pilot opened the throttle and took the plane back into the air. There was a stunned silence in the aircraft. Lisa, looking at me at her side, said quietly, ‘Thank God—we’re going home!’”

They were not going home. The pilot looped back around and landed the plane without incident. Emerging later from customs, the Thackerays saw an Argonne man with a sign. Greeting the family, he bestowed a silver dollar on each of the daughters. The gesture swept aside Lisa’s apprehensions about life in a new country.

Work started at once. Thackeray adopted Chris Johnson as a protégé and took him along to an international lithium battery conference in Boston. Arriving there, Johnson watched as a slew of scientists greeted Thackeray in the hotel lobby. “Everyone knew Mike,” Johnson said. “Everyone was coming up to him. ‘How are you doing? I understand you are at Argonne now.’ I am thinking, ‘Wow, he is really major in the field. And this is going to be a really nice relationship.’”

Thackeray began to brief Johnson about his plan. If you reduced the amount of expensive cobalt in the cathode and substituted plentiful manganese in its place, you could make batteries that were both cheaper and safer than Goodenough’s industry-standard chemistry. But you could only use so much manganese because it tended to degrade over time and destroy the battery’s performance. Instead, you needed to deploy it together with nickel, which preserved the manganese and hindered its degradation. That made the ideal compound a combination of nickel, manganese, and cobalt, or NMC, coupled of course with lithium.

Yet while this formulation was striking, it did not break new ground. The problem was that physics stepped in and spoiled Thackeray’s picture. Nickel, manganese, and cobalt, it turned out, would come apart just like Goodenough’s formulation if you sent too much lithium into the shuttling motion between electrodes that created electricity.

Thackeray thought back to South Africa. He had learned that a compound of lithium, manganese, and oxygen that went by the atomic lettering Li
2
MnO
3
was electrochemically inactive. It was normally cast aside as an impurity. But now Thackeray’s intuition told him the story was incomplete—he thought there could be more to the material than anyone knew. His idea was to add a bit of Li
2
MnO
3
to the lithium-laced NMC. Thackeray suspected that this twist would buttress the NMC and keep the cathode intact as the battery was charged and discharged.

In 1994 and 1995, Johnson created test battery cells using the formulation that Thackeray described and intercalated the lithium. He found that he was able to shuttle well over half the lithium between the two electrodes, all while the NMC structure held very much together. It was as though the cathode had been waiting for the Li
2
MnO
3
to provide it stability.

Johnson learned why Thackeray’s intuition was correct. Even though the Li
2
MnO
3
was itself inactive when introduced into a cathode, its manganese and lithium went on to migrate and lodge in the NMC like pillars. These atoms propped up the structure while the lithium in the NMC began to shuttle.

Visually, both NMC and Li
2
MnO
3
resemble a stripped-down house. The floor and ceiling are made of oxygen atoms, and the walls comprise nickel, cobalt, and manganese. Scientists call this framework a lattice. Because the lattices of the NMC and the Li
2
MnO
3
are similar, Johnson could easily integrate the two at the nanoscale.

If the only notable thing was that the compound now held together, Johnson would have been engaged in a mere thought exercise. But stability wasn’t their only success. If you were thinking about an electric car, the NMC led to a better cathode than Goodenough’s lithium-cobalt-oxide, his lithium-iron-phosphate, or Thackeray’s own manganese spinel. Not only was it cheaper and safer, but Thackeray also calculated that the extra lithium in the system improved its performance. The double lattice let you pull out 60 or 70 percent of the lithium before collapsing, well over the 50 percent you could withdraw from Goodenough’s lithium-cobalt-oxide. That extra lithium—the added 10 or 20 percent—meant more energy.

Thackeray called the invention “layered-layered,” or “composite.”

This double lattice had another advantage. It set up Thackeray for future advances. He could swap other metals in and out of the latticework to make more improvements.

As it was, though, the NMC was already potent. It overcame an essential challenge facing batteries if they were ever to compete against gasoline propulsion, and that was that very few people would settle for a single trait in an electric car. The ability to travel a long distance was important, but it was not sufficient; drivers demanded other qualities, too. They wanted the car to take off—immediately—when they pressed the accelerator, and to keep on accelerating to high speeds. They insisted that their vehicle be safe—consumers, not to mention regulators, would reject any car with a chronically explosive battery. The last quality was possibly the hardest to deliver: pushing for such performance in distance and acceleration tended to make the battery more dangerous.

Cars equipped with Argonne’s NMC formulation could travel forty miles on a single charge, a key technological marker because it was the distance that the average American motorist drove in a day. If you did not meet that metric, you couldn’t really think about putting a model on the road. The NMC also provided the rapid acceleration demanded by Americans. And manganese made the system safe.

All in all, NMC was superior to any cathode thus far produced in the national laboratories, even, some said, to anything designed elsewhere.

The breakthrough bucked up Thackeray, who seemed endlessly curious tinkering with the narrow range of elements on the periodic table relevant to batteries—but only if he intuited the potential for a meaningful advance. No one could predict commercial interest, which often seemed unfathomable. Why, after all these years, did Goodenough’s lithium-cobalt-oxide remain the standard lithium-ion formulation, used in virtually every cell phone, tablet, and laptop on the planet? No one else’s work—even Thackeray’s spinel—had been good enough to eclipse the old man. That illustrated the extremely slender chance of commercializing something new. Still, there had to be the chance of outdoing Goodenough—of progressing toward the ultimate goal, which was challenging the provenance of the internal combustion engine. Otherwise Thackeray was not interested.

He began to assemble a patent application for his NMC.

 • • • 

In May 2000, Thackeray flew to Italy’s Lake Como for a two-week lithium-ion conference. The setting was symbolic—Alessandro Volta was born in Como in 1745. Just eight months earlier, the city had hosted the bicentennial celebration of Volta’s invention of the battery. Some two hundred experts from thirty countries had gathered to mark the occasion. But Thackeray was disappointed to find little feeling of the past at the May event. For starters, it was held at a conference center a train ride away from the city, where he found the atmosphere sterile.

Thackeray delivered one of the opening presentations. Mid-morning the next day, he sat in on a thirty-minute talk by four scientists from New Zealand. In excited language, the men spoke mysteriously of a new approach to batteries coupling chromium with manganese oxide. Later, Thackeray strolled by a poster display manned by one of the New Zealanders, a crystallographer named Brett Ammundsen, and found him frustrated. “You of all people will know what I’m doing,” Ammundsen said. Surely Thackeray, the pioneer of manganese spinel back at Oxford, grasped the significance of the New Zealand advance even if no one else at Como seemed to.

At that moment Thackeray
did
comprehend what the New Zealanders were up to: treading on his turf.

For Thackeray, they were uncomfortably close to his maneuver with Li
2
MnO
3
—
just as he was, they were injecting added lithium to juice the performance of a cathode, in their case a chromium-and-manganese oxide formulation.

An alarmed Thackeray telephoned Chris Johnson in Chicago.

“Quick, do a couple of more experiments and then write up an invention report,” Thackeray said. “We are going to file for a provisional patent.” The patent he had been preparing was not quite ready. But now it needed to be if he was to get the jump on the New Zealanders.

A “provisional patent” was a tactical move—it was what you filed when you had confidence in your idea, were in a race with rivals, but lacked sufficient data. It provided a full year to validate your claim. If you found your data, you could be awarded a full patent, dated when you originally filed. Johnson dropped what he was doing and went to work. When Thackeray arrived back in Chicago, they both began to produce test cells and create electrochemical data that more or less validated their claim to greater performance. They sent off the data to the lab’s outside lawyer. In a diagram, Thackeray claimed broad priority for a cathode combining nickel, manganese, and any third metal. A year later, they filed and were awarded the permanent patent.

They had beaten the New Zealanders. But Thackeray needn’t have worried. It was a long six months after Lake Como before the New Zealand group filed its own patent application. Reading it, Thackeray found it mediocre. The New Zealanders had “missed the big picture,” he thought. It was as though they did not understand that the key to the material was the interaction of the two lattices—the use of the Li
2
MnO
3
to stabilize the NMC structure. Rather than a composite of two structures—the central fact of the formulation, Thackeray posited—the New Zealanders thought it was a homogenous mishmash of metals.