Lithium-ion batteries just made a big leap into a small product

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

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

Now the company is bringing its product to market for the first time, providing a portion of the anode powder in the battery of the next Howl 4.0, a wearable fitness. It’s a small device but potentially a big step forward for the battery field, where promising lab results often don’t translate into commercial success.

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

Battery cells produced with silicon particles from Sila.


The company’s materials, with a little help from other advancements, increased the energy density in the fitness tracker’s battery by about 17%. That’s a significant gain in a field that is generally advancing a few percentage points a year.

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

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

For the transportation sector, a more energy-dense battery can reduce costs or extend the range of electric vehicles, addressing two of the biggest problems that have discouraged consumers from stopping using gasoline. It also promises to deliver grid batteries that can save more energy from solar and wind farms, or consumer devices that last longer between charges.

Energy density is the key to “electrifying everything,” says Berdichevsky, a Innovator under 35 in 2017.

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

Sulla, who announced $ 590 million in financing In January, it also has partnerships to develop battery materials for automakers like BMW and Daimler. The company has said its technology could eventually pack up to 40% more energy in lithium-ion batteries.

Prevent fires

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

Established a program to systematically evaluate a series of battery pack designs. After hundreds of tests, the company developed a combination of battery arrays, heat transfer materials, and cooling channels that largely prevented wildfires.

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

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

Gene Berdichevsky, CEO and co-founder of Sila.


Berdichevsky returned to Stanford to pursue a master’s program in the study of materials, thermodynamics, and physics, hoping to find ways to improve storage at the fundamental level. After graduation, he spent a year as a resident entrepreneur at Sutter Hill Ventures, looking for ideas that could form the basis of his own business.

During that time, he met a scientist paper identify a method to produce silicon-based particles for lithium-ion battery anodes.

Researchers have long viewed silicon as a promising way to boost energy in batteries, because its atoms can bond with 10 times more lithium ions by weight than graphite. That means they contain many more charged molecules that produce the electrical current in a battery. But the silicon anodes tended to crumble during charging, as they swelled to accommodate the ions that come and go between the electrodes.

The paper, co-authored by Georgia Institute of Technology professor Gleb Yushin, highlighted the possibility of developing rigid silicon materials with a porous core that could more easily accept and release lithium ions.

The following year, Berdichevsky co-founded Sila with Yushin and Alex Jacobs, another former Tesla engineer.

Obstacles and delays

The company spent the next decade fine-tuning its methods and materials, working on more than 50,000 iterations of the chemistry while increasing its manufacturing capacity. From the beginning, it decided to develop direct materials that lithium-ion battery manufacturers could trade in, rather than going the more expensive and risky route of producing complete batteries themselves.

However, Sulla is not as advanced as she originally hoped.

After obtaining several million dollars from the US Department of Energy’s ARPA-E division, the company at one point told the research agency that its materials could be in products by 2017 and in vehicles by 2020. In 2018, when Sila announced his deal with BMW, he said its particles could help power the German automaker’s electric vehicles by 2023.

Berdichevsky says the company now hopes to be in vehicles by “more like 2025.” He says solving the “last mile” problems was simply more difficult than they expected. The challenges included working with battery manufacturers to get the best performance from the new materials.

“We were naively optimistic about the challenges of scaling and bringing products to market,” he said in an email.

The Whoop news indicates that Sila was able to engineer the particles in a way that offers safety, life cycles and other battery performance benchmarks similar to those achieved in existing products.

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