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Stellantis partner promises a better, safer EV battery delivering more range

When Siyu Huang was a child, she had a passion for sustainability. Now, she's the CEO of a company developing the electric-vehicle batteries striving to alleviate range anxiety in customers and give the makers of Jeep and Mercedes-Benz confidence in EV safety.

Huang is behind Factorial Inc., a solid-state battery developer based in Woburn, Massachusetts, outside of Boston in the race to make what could be some of the most significant strides in battery technology in decades.

Factorial is the first company, Huang says, to produce a 40-amp-hour solid-state battery that operates at room temperature. Cells that'll go into EVs will need to be bigger than that, but the breakthrough has been enough to get the backing of Stellantis NV, Daimler AG's Mercedes-Benz and Hyundai Motor Co. and Kia Corp., which share many suppliers.

"It delivers the safety to the automotive OEMs," Huang said of Factorial's solid-state batteries. "At the same time, it enables higher energy density, which means there's a longer range."

Factorial's batteries offer 20% to 50% more energy density than the lithium-ion batteries found in today's electric vehicles, Huang says. That's from a lithium metal anode as opposed to the graphite and sometimes silicon materials in conventional EV battery anodes. This helps increase the vehicle's range — the top barrier to EV adoption — from 300 miles with lithium-ion batteries to up to 450 miles with Factorial's batteries.

Its cells catch fire at a temperature more than double that of lithium-ion batteries, too. So, in the instance of a crash or a manufacturing defect like the one that has led to a nearly $2 billion recall of every single Chevrolet Bolt EV that General Motors Co. has produced for a fire risk, they're less likely to ignite.

Huang has a doctorate and a master's in business administration from Cornell University after starting her career in biofuel research in Sweden. Out of a business plan competition at Cornell, she launched Lionano Inc., a provider of materials for lithium-ion batteries. Then came Factorial Energy (Factorial Inc.'s marketed brand), emerging from its secretive work in April with its 40-amp-hour cell.

Factorial has "already overcome a major challenge with that," she said. Growing the size of the technology, "that's really the death valley of battery startups because a lot of companies, they can demonstrate a battery performance as far as small scale, but it's really hard to move to the bigger format."

Huang hopes the batteries will be ready for mass manufacturing starting around 2026 — when Stellantis CEO Carlos Tavares earlier this month said the automaker expects to start production. The partnership, he said, will save on costs and hasten the timeline to the market. 

For comparison, Solid Power, a Colorado-based solid-state battery producer that's received investment from Ford Motor Co. and BMW AG, predicts it will be in production with fully solid-state batteries by 2025 and in vehicles for commercial sale in 2026. Batteries with lithium metal anodes are expected to begin production in 2027.

“Everybody is looking for the potential next big breakthrough,” said Sam Abuelsamid, principal e-mobility analyst for market research firm Guidehouse Inc. “Ideally, they would like today to find somebody with the right mix of technology. If they think it’s the best solution, and they’re the only ones with it, that’s a potential competitive advantage in the marketplace.”

Between Lionano and Factorial, Huang's closed series of financing totaling more than $65 million from venture capital and private equity firms in the United States and Europe. The American Chemical Society last year named Factorial one of 10 startups to watch.

"Siyu is an astonishingly talented individual with an exceptional command of both fundamental and practical (applied) aspects of battery technologies. She also has tremendous business savvy," Héctor Abruña, a Cornell chemistry professor who specializes in battery materials, said in an email. He is a founder of Factorial alongside Huang and Yingchao "Alex" Yu, another Cornell graduate.

Huang "has provided the drive and vision for Factorial Energy’s thrust into solid state batteries."

Factorial's chairman is Joe Taylor, former CEO of battery manufacturer Panasonic Corp. In North America, and its advisory board consists of Daimler's former chairman; Mark Fields, Ford's former CEO; and a member of the Obama administration's auto task force board. The company employs 60 people, with plans to double that over the next year, though the biggest challenge is finding the engineering and scientist talent, Huang said.

In the development of Lionano, "we also recognize that the entire industry is moving to higher and higher energy density, which is what our material was taking to, but also it has a lot of problems with the safety," she said. "Starting from six, seven years ago, we started to contemplate about a technology that can hit high energy density, but also at the same time, provide a great safety profile."

That solution is solid-state batteries, which don't have the flammable liquid electrolyte through which the ions of lithium-ion batteries travel to charge and discharge the battery. Factorial's cells instead use Factorial Electrolyte System Technology, or FEST for short. It's a polymer-based electrolyte whose flashpoint — the temperature at which the compound ignites — is at about 392 degrees Fahrenheit compared to about 158 degrees for lithium-ion batteries. That means Factorial's batteries are less likely to catch fire.

"If there's any damage to the cell or a crash happens or a defect happens, there's a little bit of heating within the cell, which can start explosions very quickly," Huang said of what is known as thermal propagation or thermal runaway in lithium-ion batteries. "Solid-state is safer."

One challenge with solid-state batteries is that because the electrolyte is solid, it takes longer for ions to move within the battery, Abruña said. This reduces conductivity, which can limit acceleration and how many times a battery can be recharged.

FEST, however, uses "solid state battery materials that deliver in all of the promise of solid-state batteries without compromising performance," the professor said.

FEST also is compatible with the existing lithium-ion battery manufacturing processes, which means the investments automakers are making now for battery manufacturing won't go to waste.

"That's really, really important for us as a practical company's view because there are going to be more than $100 billion to $200 billion invested into lithium-ion ore battery manufacturing over the next 10 years," Huang said. "We will be able to adapt to more than 90% of today's lithium-ion manufacturing process with minimal adjustments."

Stellantis has announced plans for two battery plants in North America, one each with LG Energy Solution starting in 2024 and Samsung SDI in 2025.

Technically, Factorial's first-generation batteries are what Huang calls "quasi-solid-state batteries." To scale the manufacturing of fully solid-state batteries requires cells to be put under enormous amounts of external pressure — typically 10 or 20 times atmospheric pressure. Some forms of inorganic solid electrolyte are too brittle to withstand that external force.

Factorial's quasi-solid-state batteries add a liquid to the interface, which is between the solid electrolyte and electrodes — the anode and cathode, which are the positive and negative sides of a battery. This helps to decrease the interfacial resistance so that ions can travel between the electrolyte and the electrodes without as much external pressure. This eases the manufacturing process.

All-solid-state batteries in the long-term are the goal, Huang said, but that timeline is closer to 2030 or later when the commercial scale of the needed materials grows.

In forming partnerships with automakers, Factorial has new investments in its research and development. Its focus now is turning to the module level, which is a cluster of cells, and testing with automakers for vehicle validation.

Eventually, Factorial hopes to form joint ventures with automakers to manufacture its cells, which Huang says will be the fastest way to get the batteries to market.

"We want to produce globally and where it is most convenient," she said. The way to achieve a "minimum carbon footprint is to build something close to our customers."

Twitter: @BreanaCNoble