Researchers and companies around the world are racing to solve the problem of storing clean energy when the sun isn’t shining on solar farms or the wind isn’t turning turbines. Of course, good batteries are already in common use in electric vehicles and Tesla Power walls, but those batteries rely primarily on lithium, cobalt, manganese, nickel, and other rare materials. They’re expensive, flammable, and their materials are available in limited supplies and from just a few locations, including in China, Congo, and some of the deepest parts of the ocean.
In a future with massive electricity storage needs, batteries made of cheaper, easier-to-obtain ingredients will be a must.
Sadoway says he has developed one that uses aluminum and sulfur, both plentiful and readily available, which he detailed in a recent paper in the journal Nature, and is now in the process of testing.
“With this technology, there’s no need to rely on the Congo or China for the materials,” said Sadoway, a professor emeritus of materials chemistry at the Massachusetts Institute of Technology. “It’s ethically sourced, cheap, effective, and can’t catch fire.”
The battery problem has been looming for some time. While the costs of lithium have risen by as much as three times over the past year from a combination of the rising demand for electric vehicles and supply disruptions in China, lithium-ion batteries have nevertheless become less expensive and more effective in recent years, spurring a boom in the energy storage industry.
Since 2020, the amount of large-scale energy storage designed to back up the electrical grid has more than quadrupled in the United States, with the capacity now to store about 6.5 gigawatts of electricity, according to the American Clean Power Association, an industry trade group. A gigawatt of electricity, or a thousand megawatts, is enough to power roughly 700,000 homes.
Smaller energy storage systems for homes and businesses have also grown significantly, with a record of more than 700 megawatt hours of capacity installed in the first half of this year.
But the nation is likely to require hundreds of gigawatts of storage capacity over the coming years — more than a hundred times what exists today — to ensure the lights stay on when renewable energy sources stop producing electricity or fail to produce enough.
With rising global demand and decreasing supply for the materials used in current batteries, it will be difficult to create a carbon-free economy without new battery technology, energy analysts say.
That pressure on the system will only grow as more offshore wind and solar replace oil and natural gas, requiring storage facilities that can maintain the electricity for longer periods, said Jason Burwen, vice president of energy storage at the American Clean Power Association.
“It’s vital we do everything in the US we can to bring new technology to market,” he said. “It will be critical to the reliability of the system.”
In New England, where the first major offshore wind farm is being developed in waters south of Martha’s Vineyard, there are numerous projects planned for large-scale energy storage. One lithium-ion project in Carver, slated to open in two years and expected to be among the region’s largest such plants, will be able to store 150 megawatts of energy in dozens of shipping container-sized structures near an Eversource substation.
But overall, the promised storage facilities have been slow to materialize, in part because of the global supply chain crisis and challenges connecting battery plants to the grid. Nationally, more than one gigawatt of projects scheduled to come online this year have been delayed or canceled as a result of those issues, according to the American Clean Power Association.
Massachusetts already has more than 300 megawatt hours of energy storage capacity, with 800 more planned, according to the state’s climate plan. The state has set a goal of installing 1,000 megawatt hours of large-scale energy storage by 2025.
Environmental advocates in Massachusetts said they’re hopeful that technological breakthroughs would accelerate the adoption of large battery storage systems, especially as thousands of megawatts of new offshore wind are built in the region’s waters.
Kyle Murray, a senior policy advocate at the Massachusetts Acadia Center, called the state’s current rate of adoption “woefully slow.”
“We need to speed up the process so we can meet our state decarbonization goals and tackle the climate emergency,” he said. “We currently have batteries that can already do some wonderful things for society, and we need to be deploying more of them. That needs to be paired with developing and deploying new, amazing technologies.”
Bringing hope to that wish, the market for new battery technology is suddenly hot. Money has poured into a generation of Massachusetts startups now racing to develop better, lighter, and longer-lasting storage. The landscape is also dotted with those who tried and failed, notably the legendary bankruptcy a decade ago of another MIT spinoff, A123 Systems, which despite promising new technology was unable to be commercially successful.
In his office in Watertown, where 15 employees are working in 20,000 square feet of mainly empty space, Sadoway is hoping for a different outcome, and to upend the market for energy storage.
With $8 million raised from investors for his new company, Avanti — named for an old sports car he loved — Sadoway plans to fill the office with more employees and machinery to test and build his batteries.
“We have to demonstrate that this technology is ready to release into a customer’s hands,” he said.
For electrodes, his batteries use aluminum, the planet’s most abundant metal, and another abundant material, sulphur. In between, they use a widely available molten salt to sustain an electrical current.
In early experiments described in the Nature paper, Sadoway was able to show his battery could undergo hundreds of charging cycles without losing much of its capacity. They cost about one-sixth of the price, per cell, of lithium-ion batteries.
Sadoway’s team is working on a prototype similar to that of a Tesla Powerwall, although they say it should cost half the price and last 10 times longer. They envision the batteries, about the size of a refrigerator, could also eventually store energy from the grid and power vehicles.
“That would be 40 hours of coverage for one house, enough to get through times when you’re not getting all the renewable energy you need,” said Luis Ortiz, Avanti’s chief executive and a former student of Sadoway’s at MIT.
While hopeful the technology will prove viable, other battery researchers are skeptical about Avanti’s ambitions.
“It’s good to be excited, but to call it a holy grail is premature,” said Robert Messinger, an associate professor of chemical engineering at the City College of New York, who has spent years studying batteries. “One should be cautious any time a new battery technology has been proposed.”
He and others noted the operating temperature of the battery is more than 200 degrees, which is considered high, and that the molten salt electrolytes are highly acidic and could be corrosive to other components of the battery.
Juchen Guo, chair of the materials science and engineering program at the University of California Riverside, said “there are questions about this technology that need to be answered.”
“It’s super safe, and the capacity is relatively high, but I remain skeptical,” he said. “The high temperatures could be a big obstacle for wide applications.”
For Sadoway, the next few years will give his company the time to answer the skeptics and prove whether their technology is viable.
Sadoway has a track record of bringing new battery technology from the lab to the market. A previous company he started, Ambri, was just selected to provide its liquid metal battery technology to build a large energy storage facility for Microsoft.
That technology, he said, was designed to provide energy storage for much larger facilities, although it’s possible his newer, cheaper batteries could eventually displace the need for liquid metal. Ambri’s batteries operate at temperatures nearly five times those of the newer ones being developed and can store as much as 100 megawatts of energy.
With significant new tax incentives for battery technology in the recently passed Inflation Reduction Act, Sadoway’s team in Watertown is racing to complete a prototype by the end of 2023.
Their goal is to sell the batteries for no more than $6,000, “as soon as possible,” he said.
“We’re moving as quickly as we can,” Sadoway said.
In response to the skeptics, he noted there were significant doubts raised about the efficacy of lithium-ion batteries when scientists first began proposing them in the 1990s.
“Reading the early literature, who would have believed that chemistry would create a multibillion-dollar industry?” he said. “We have a lot of work to do.”
David Abel can be reached at email@example.com. Follow him on Twitter @davabel.