Donald Sadoway is the Mr. Chips, the Mr. Holland, the Miss Jean Brodie of the Massachusetts Institute of Technology. The elfin 65-year-old from Oshawa, Ontario, is the sort of teacher who alums discuss fondly at reunions. Remember the class on the chemistry of Champagne, when he wore a tuxedo and served flutes of bubbly?
Or how he blasted Handel's Water Music at the start of the class on how hydrogen bonds with oxygen?
Sadoway has won almost every teaching award they have at MIT, some of them multiple times. But he also explodes that nasty old distinction between teachers and doers. He is an inventor with 19 patents, and he's about to launch a battery that could change the world. "As we try to wean ourselves from fossil fuels, what's the big question everyone is trying to answer?" he asks, one of many rhetorical questions he poses in our interview. "It's this: How do you store the energy generated by turbines when the wind isn't blowing, the power from solar panels when the sun isn't shining?"
We meet on the spring day Elon Musk announces Tesla's plan to release a line of batteries for use by homeowners and utilities. (1) It's chilly, but he's wearing khaki shorts. Looking out from his beach house on the California coast, it's hard to discern the line between ocean and sky. Neither the day's gloominess nor Musk's announcement curbs his enthusiasm. "It's a big market," he says. "I'm not the least bit bothered that there are other people out there trying to commercialize batteries." (2)
From Edison's day on, every would-be inventor has had a revolutionary, fail-safe battery in mind. (3) But Sadoway has cause to be optimistic about his molten metal battery. For one thing, it's got Bill Gates backing it.
It is fitting that it was Sadoway's teaching that drew Gates to him: The Microsoft founder took a Sadoway chemistry class online, and had an assistant propose a meeting. "I ignored the e-mail," Sadoway says. "I thought it was a student prank, but when she wrote back, saying she was in fact writing on behalf of Bill Gates, we met in Cambridge and talked about many things: the role of the Internet, engineering education, climate change. I sketched some theory out on a whiteboard. He said if you ever decide to spin this out as a company, let me know."
Sadoway did decide to spin it out, and Gates duly came through as a backer (as did the hotel-owning Pritzker family). And now, some 50 employees at a plant in Marlborough, Massachusetts, are producing the first batteries under the Ambri brand (a name derived from Cambridge). The batteries will generally be eight-inch-square, two-inch-tall units, joined together in varying sizes and able to store one megawatt. So far, a mix of utilities, renewable power generators and military bases have placed orders—Pearl Harbor has bought a supersized one. Phil Giudice, the long-time energy executive Sadoway persuaded to head the start-up, says pricing is yet to be determined. "We'll probably come in at a slightly lower rate than the competition," he says. In our interview, Sadoway outlines his battery's progress. He used MIT students, not battery experts, to refine the concept and move from idea to prototype to product. "Students are idealistic and don't recognize that something is impossible."
When one grad student informed him that an initial proposed battery—involving a metal and sulphur gas—couldn't work, he remembers staring at the periodic table on his desk and realizing "we needed to have two metals that were as different as could be in behaviour. There were strong metals in the northwest part of the table, weaker ones in the southeast. To get a bit technical, one needed to be a good electron donor, the other a good acceptor."
He also wanted the source metals to be both common and readily available in North America. "Petroleum is abundant, but it's maldistributed globally.
I wanted our materials to be as common as dirt here." And so the battery will rely on low-cost materials whose identities remain secret. At 500 C, these mystery metals liquify and send current through a layer of molten salt.
The battery's other key strength, according to Sadoway, is its ability to be recharged frequently, which he contrasts with the popular lithium-ion batteries used in many smartphones and electric vehicles. "Those are high-cost and tend to retain their capacity of charge for two to three years—long enough for a phone, but not for a home, or even a car."
The house on Monterey Bay is a recent purchase by Sadoway and wife Rebecca Rosenberg. There are no other houses visible from this lonely stretch, only sea and sand and sky. The bookshelves are lined with poetry (Seamus Heaney), fiction (Mordecai Richler) and history (much about his ancestral homeland, Ukraine). It's an ideal spot to think big thoughts, and Sadoway closes with a few. "We have the ingenuity to solve the problems we've created. But there's political paralysis—you're a traitor if you reach across the aisle. When I started, all the big companies had massive research departments: Alcan, Stelco, Falconbridge. These have been decimated—and privately funded research now tends to be short-term. It's all about the quarterlies. Still, I remain optimistic. With people like Gates, there's this determination to leave something better behind."
1) Tesla reportedly hired another Canadian academic-inventor, Dalhousie's Jeff Dahn, in connection with its forthcoming nickel-manganese-cobalt battery.
2) Navigant Research projects revenues for the global battery market to rise from last year's $452 million (U.S.) to about $16.5 billion by 2024.
3) Inventors so pestered Thomas Edison that he once commented: "Just as soon as a man gets working on the secondary battery, it brings out his latent capacity for lying."