British defense contractor BAE Systems has entered into a three-year cooperation agreement with lithium-ion battery developer Amprius Technologies, the companies announced last week. Amprius will supply BAE with lightweight and high-energy batteries for electric aviation applications, while leaving the door open to other possible uses in BAE’s defense technologies.
Amprius is a Fremont, California-based company developing high-energy lithium-ion batteries with silicon nanowire anode technology. The company claims that its batteries deliver the highest energy density of any existing lithium-ion batteries.
“Amprius has engaged with many companies to provide our cells to power their electric propulsion systems,” a company spokesperson told FutureFlight. “Amprius has also provided batteries for the high-performance, high-altitude experimental drone aircraft manufactured by Airbus Defense and Space for the U.S Army. The Airbus Zephyr flew for 64 days straight, partially thanks to its Amprius battery packs. Since we offer the only commercially available lithium-ion cells over 450 Wh/kg that contain the performance advantage of a 100 percent silicon anode, Amprius Technologies is well-positioned to capitalize on the growing electric aviation market.”
Whereas most lithium-ion batteries use graphite powder or other carbon materials for their anode—the negatively charged electrode inside the battery—Amprius uses silicon, which can store up to 10 times more lithium and therefore has a significantly higher charging capacity.
However, silicon also tends to swell and crack when charged with lithium, which can cause batteries to stop working. To solve that problem, Amprius has developed anodes with silicon nanowires, a configuration that tolerates the swelling and is resistant to cracking. The silicon nanowire anodes replace the traditional graphite anodes, while the rest of the battery’s components are the same as with other lithium-ion batteries.
“Amprius’s innovative silicon nanowire anode battery cells have the potential to deliver exceptional performance, and so we’re keen to work with them to explore opportunities for the electric products that we’re developing for military applications,” said Dave Holmes, advanced projects, technology and manufacturing director at BAE Systems’ Air.
The Amprius spokesperson told FutureFlight that the company's silicon anode batteries can be used in any product that utilizes battery technology, including any electric products that BAE is developing for military applications. For example, BAE's product portfolio includes electronic warfare systems that detect and disable radio frequency threats, surveillance and reconnaissance sensors, communications equipment, and military vehicles for air, land, and sea.
“BAE Systems is at the technological forefront of the defense industry, and this agreement validates the potential of our silicon nanowire anode technology for rigorous aerial applications,” said Amprius CEO Kang Sun.