A materials company in Alameda, California, has spent the last decade working to boost the energy stored in lithium-ion batteries, an advance that could enable smaller gadgets and electric vehicles with far greater range.

Sila has developed silicon-based particles that can replace the graphite in anodes and hold more of the lithium ions that carry the current in a battery.

Now the company is delivering its product to the market for the first time, providing a portion of the anode powder in the battery of the forthcoming Whoop 4.0, a fitness wearable. It’s a small device but potentially a big step forward for the battery field, where promising lab results often fail to translate to commercial success.

“Think of the Whoop 4.0 as our Tesla Roadster,” says Gene Berdichevsky, Sila’s CEO, who as Tesla’s seventh employee helped solve some of the critical battery challenges for the company’s first electric vehicle. “It’s really the first device on the market that’s proving this breakthrough.”

Battery cells produced with Sila’s silicon-based particles.SILA

The company’s materials, with a light assist from other advances, increased the energy density in the fitness tracker’s battery by around 17%. That’s a significant gain in a field that generally inches forward by a few percentage points a year.

It’s equivalent to about four years of standard progress, “but in one big jump,” says Venkat Viswanathan, an associate professor of mechanical engineering at Carnegie Mellon University.

Sila still faces some real technical challenges, but the advance is a promising sign for the potential of increasingly capable batteries to help the world shift away from fossil fuels as the dangers of climate change accelerate. Boosting the amount of energy that batteries can store makes it easier for increasingly clean electricity sources to power more of our buildings, vehicles, factories, and businesses.  

For the transportation sector, a more energy-dense battery can reduce the costs or extend the range of electric vehicles, addressing two of the biggest issues that have discouraged consumers from giving up their gas guzzlers. It also promises to deliver grid batteries that can save up more energy from solar and wind farms, or consumer gadgets that last longer between charges.

Energy density is the key to the “electrification of everything,” says Berdichevsky, an Innovator Under 35 in 2017.

In the case of the new fitness wearable, the novel battery materials and other improvements made it possible for Boston-based Whoop to shrink the device by 33% while maintaining five days of battery life. The product is now thin enough to be inserted into “smart apparel” as well as being worn like a watch. It goes on sale September 8.

Sila, which announced $590 million in funding in January, also has partnerships in place to develop battery materials for automakers including BMW and Daimler. The company has said its technology could eventually pack as much as 40% more energy into lithium-ion batteries.

Preventing fires

Berdichevsky interviewed for and landed his job at Tesla before his senior year at Stanford University, where he was working toward a degree in mechanical engineering. He ended up playing a key role in addressing a potentially existential risk for the company: that a fire in any one of the thousands of batteries packed into a vehicle would ignite the whole pack.

He set up a program to systematically evaluate a series of battery pack designs. After hundreds of tests, the company developed a combination of battery arrangements, heat transfer materials, and cooling channels that largely prevented runaway fires.

After Tesla launched the Roadster, Berdichevsky felt he had to either commit to another five years to see the company through development of the next vehicle, the Model S—or take the opportunity to try something new.

In the end, he decided he wanted to build something of his own.

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By: James Temple
Title: Lithium-ion batteries just made a big leap in a tiny product
Sourced From: www.technologyreview.com/2021/09/08/1035143/sila-whoop-lithium-ion-battery-fitness-wearable-evs/
Published Date: Wed, 08 Sep 2021 16:00:00 +0000

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