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Silicone anode start-ups attract new investment

Fresh money will enable Sila Nanotechnologies and Amprius to ramp up production

by Alex Scott
November 7, 2019 | A version of this story appeared in Volume 97, Issue 44


Photo of pseudosatellite powered by silicon anode lithium-ion battery.
Credit: Airbus
Airbus's pseudosatellite on a test flight

Sila Nanotechnologies and Amprius Technologies, two firms developing silicon-rich materials as alternatives to standard graphite for lithium-ion battery anodes, have secured new private investments to help push their technologies into the marketplace.

Sila has received $45 million from the Canada Pension Plan Investment Board in exchange for equity. The investment takes the California-based company’s funds raised this year to $210 million. Sila says it will use the new cash to ramp up production. It aims to start supplying its silicon nanocomposite anode material to makers of batteries for consumer electronics starting next year.

Meanwhile, Stanford University spin-off Amprius says it has received an undisclosed “strategic investment” from the aerospace firm Airbus. Amprius’s silicon anodes are used in batteries that power Airbus’s Zephyr, a stratosphere-traveling satellite known as a pseudosatellite.

Lux Research analyst Chloe Holzinger says she expects Amprius to use the new funding “to expand production capabilities and develop a higher-capacity silicon nanowire lithium-ion battery, which will likely be used predominately in defense and aerospace applications.”

The investments in Amprius and Sila follow Wacker Chemie’s acquisition in September of a 25% stake in the UK silicon anode start-up Nexeon. The German specialty chemical firm first bought into Nexeon in 2013.

All three start-ups say their silicon-containing anode materials could increase the energy density of lithium-ion batteries by more than 20%. But for their technologies to be effective, they will have to overcome technical challenges associated with the expansion and contraction of silicon anodes during charge and discharge cycles, which can exceed 300%.

“The use of silicon in anodes will steadily increase in the next 5 years,” predicts Alex Holland, technology analyst at the UK market research firm IDTechEx. The element will find widespread use initially in batteries for portable electronics before being taken up by the automotive sector, he says.

To oust current graphite anodes, though, silicon anodes will need lower costs and better performance over a battery’s life, Holzinger says. Moreover, she adds, silicon anodes’ lead “is temporary, as we expect lithium-metal anodes to take off in the 2030s.”



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